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deparse.c
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1 /*-------------------------------------------------------------------------
2  *
3  * deparse.c
4  * Query deparser for postgres_fdw
5  *
6  * This file includes functions that examine query WHERE clauses to see
7  * whether they're safe to send to the remote server for execution, as
8  * well as functions to construct the query text to be sent. The latter
9  * functionality is annoyingly duplicative of ruleutils.c, but there are
10  * enough special considerations that it seems best to keep this separate.
11  * One saving grace is that we only need deparse logic for node types that
12  * we consider safe to send.
13  *
14  * We assume that the remote session's search_path is exactly "pg_catalog",
15  * and thus we need schema-qualify all and only names outside pg_catalog.
16  *
17  * We do not consider that it is ever safe to send COLLATE expressions to
18  * the remote server: it might not have the same collation names we do.
19  * (Later we might consider it safe to send COLLATE "C", but even that would
20  * fail on old remote servers.) An expression is considered safe to send
21  * only if all operator/function input collations used in it are traceable to
22  * Var(s) of the foreign table. That implies that if the remote server gets
23  * a different answer than we do, the foreign table's columns are not marked
24  * with collations that match the remote table's columns, which we can
25  * consider to be user error.
26  *
27  * Portions Copyright (c) 2012-2024, PostgreSQL Global Development Group
28  *
29  * IDENTIFICATION
30  * contrib/postgres_fdw/deparse.c
31  *
32  *-------------------------------------------------------------------------
33  */
34 #include "postgres.h"
35 
36 #include "access/htup_details.h"
37 #include "access/sysattr.h"
38 #include "access/table.h"
39 #include "catalog/pg_aggregate.h"
40 #include "catalog/pg_authid.h"
41 #include "catalog/pg_collation.h"
42 #include "catalog/pg_namespace.h"
43 #include "catalog/pg_operator.h"
44 #include "catalog/pg_opfamily.h"
45 #include "catalog/pg_proc.h"
46 #include "catalog/pg_ts_config.h"
47 #include "catalog/pg_ts_dict.h"
48 #include "catalog/pg_type.h"
49 #include "commands/defrem.h"
50 #include "nodes/nodeFuncs.h"
51 #include "nodes/plannodes.h"
52 #include "optimizer/optimizer.h"
53 #include "optimizer/prep.h"
54 #include "optimizer/tlist.h"
55 #include "parser/parsetree.h"
56 #include "postgres_fdw.h"
57 #include "utils/builtins.h"
58 #include "utils/lsyscache.h"
59 #include "utils/rel.h"
60 #include "utils/syscache.h"
61 #include "utils/typcache.h"
62 
63 /*
64  * Global context for foreign_expr_walker's search of an expression tree.
65  */
66 typedef struct foreign_glob_cxt
67 {
68  PlannerInfo *root; /* global planner state */
69  RelOptInfo *foreignrel; /* the foreign relation we are planning for */
70  Relids relids; /* relids of base relations in the underlying
71  * scan */
72 } foreign_glob_cxt;
73 
74 /*
75  * Local (per-tree-level) context for foreign_expr_walker's search.
76  * This is concerned with identifying collations used in the expression.
77  */
78 typedef enum
79 {
80  FDW_COLLATE_NONE, /* expression is of a noncollatable type, or
81  * it has default collation that is not
82  * traceable to a foreign Var */
83  FDW_COLLATE_SAFE, /* collation derives from a foreign Var */
84  FDW_COLLATE_UNSAFE, /* collation is non-default and derives from
85  * something other than a foreign Var */
86 } FDWCollateState;
87 
88 typedef struct foreign_loc_cxt
89 {
90  Oid collation; /* OID of current collation, if any */
91  FDWCollateState state; /* state of current collation choice */
92 } foreign_loc_cxt;
93 
94 /*
95  * Context for deparseExpr
96  */
97 typedef struct deparse_expr_cxt
98 {
99  PlannerInfo *root; /* global planner state */
100  RelOptInfo *foreignrel; /* the foreign relation we are planning for */
101  RelOptInfo *scanrel; /* the underlying scan relation. Same as
102  * foreignrel, when that represents a join or
103  * a base relation. */
104  StringInfo buf; /* output buffer to append to */
105  List **params_list; /* exprs that will become remote Params */
106 } deparse_expr_cxt;
107 
108 #define REL_ALIAS_PREFIX "r"
109 /* Handy macro to add relation name qualification */
110 #define ADD_REL_QUALIFIER(buf, varno) \
111  appendStringInfo((buf), "%s%d.", REL_ALIAS_PREFIX, (varno))
112 #define SUBQUERY_REL_ALIAS_PREFIX "s"
113 #define SUBQUERY_COL_ALIAS_PREFIX "c"
114 
115 /*
116  * Functions to determine whether an expression can be evaluated safely on
117  * remote server.
118  */
119 static bool foreign_expr_walker(Node *node,
120  foreign_glob_cxt *glob_cxt,
121  foreign_loc_cxt *outer_cxt,
122  foreign_loc_cxt *case_arg_cxt);
123 static char *deparse_type_name(Oid type_oid, int32 typemod);
124 
125 /*
126  * Functions to construct string representation of a node tree.
127  */
128 static void deparseTargetList(StringInfo buf,
129  RangeTblEntry *rte,
130  Index rtindex,
131  Relation rel,
132  bool is_returning,
133  Bitmapset *attrs_used,
134  bool qualify_col,
135  List **retrieved_attrs);
136 static void deparseExplicitTargetList(List *tlist,
137  bool is_returning,
138  List **retrieved_attrs,
139  deparse_expr_cxt *context);
140 static void deparseSubqueryTargetList(deparse_expr_cxt *context);
141 static void deparseReturningList(StringInfo buf, RangeTblEntry *rte,
142  Index rtindex, Relation rel,
143  bool trig_after_row,
144  List *withCheckOptionList,
145  List *returningList,
146  List **retrieved_attrs);
147 static void deparseColumnRef(StringInfo buf, int varno, int varattno,
148  RangeTblEntry *rte, bool qualify_col);
149 static void deparseRelation(StringInfo buf, Relation rel);
150 static void deparseExpr(Expr *node, deparse_expr_cxt *context);
151 static void deparseVar(Var *node, deparse_expr_cxt *context);
152 static void deparseConst(Const *node, deparse_expr_cxt *context, int showtype);
153 static void deparseParam(Param *node, deparse_expr_cxt *context);
154 static void deparseSubscriptingRef(SubscriptingRef *node, deparse_expr_cxt *context);
155 static void deparseFuncExpr(FuncExpr *node, deparse_expr_cxt *context);
156 static void deparseOpExpr(OpExpr *node, deparse_expr_cxt *context);
157 static bool isPlainForeignVar(Expr *node, deparse_expr_cxt *context);
158 static void deparseOperatorName(StringInfo buf, Form_pg_operator opform);
159 static void deparseDistinctExpr(DistinctExpr *node, deparse_expr_cxt *context);
160 static void deparseScalarArrayOpExpr(ScalarArrayOpExpr *node,
161  deparse_expr_cxt *context);
162 static void deparseRelabelType(RelabelType *node, deparse_expr_cxt *context);
163 static void deparseBoolExpr(BoolExpr *node, deparse_expr_cxt *context);
164 static void deparseNullTest(NullTest *node, deparse_expr_cxt *context);
165 static void deparseCaseExpr(CaseExpr *node, deparse_expr_cxt *context);
166 static void deparseArrayExpr(ArrayExpr *node, deparse_expr_cxt *context);
167 static void printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod,
168  deparse_expr_cxt *context);
169 static void printRemotePlaceholder(Oid paramtype, int32 paramtypmod,
170  deparse_expr_cxt *context);
171 static void deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_attrs,
172  deparse_expr_cxt *context);
173 static void deparseLockingClause(deparse_expr_cxt *context);
174 static void appendOrderByClause(List *pathkeys, bool has_final_sort,
175  deparse_expr_cxt *context);
176 static void appendLimitClause(deparse_expr_cxt *context);
177 static void appendConditions(List *exprs, deparse_expr_cxt *context);
178 static void deparseFromExprForRel(StringInfo buf, PlannerInfo *root,
179  RelOptInfo *foreignrel, bool use_alias,
180  Index ignore_rel, List **ignore_conds,
181  List **additional_conds,
182  List **params_list);
183 static void appendWhereClause(List *exprs, List *additional_conds,
184  deparse_expr_cxt *context);
185 static void deparseFromExpr(List *quals, deparse_expr_cxt *context);
186 static void deparseRangeTblRef(StringInfo buf, PlannerInfo *root,
187  RelOptInfo *foreignrel, bool make_subquery,
188  Index ignore_rel, List **ignore_conds,
189  List **additional_conds, List **params_list);
190 static void deparseAggref(Aggref *node, deparse_expr_cxt *context);
191 static void appendGroupByClause(List *tlist, deparse_expr_cxt *context);
192 static void appendOrderBySuffix(Oid sortop, Oid sortcoltype, bool nulls_first,
193  deparse_expr_cxt *context);
194 static void appendAggOrderBy(List *orderList, List *targetList,
195  deparse_expr_cxt *context);
196 static void appendFunctionName(Oid funcid, deparse_expr_cxt *context);
197 static Node *deparseSortGroupClause(Index ref, List *tlist, bool force_colno,
198  deparse_expr_cxt *context);
199 
200 /*
201  * Helper functions
202  */
203 static bool is_subquery_var(Var *node, RelOptInfo *foreignrel,
204  int *relno, int *colno);
205 static void get_relation_column_alias_ids(Var *node, RelOptInfo *foreignrel,
206  int *relno, int *colno);
207 
208 
209 /*
210  * Examine each qual clause in input_conds, and classify them into two groups,
211  * which are returned as two lists:
212  * - remote_conds contains expressions that can be evaluated remotely
213  * - local_conds contains expressions that can't be evaluated remotely
214  */
215 void
216 classifyConditions(PlannerInfo *root,
217  RelOptInfo *baserel,
218  List *input_conds,
219  List **remote_conds,
220  List **local_conds)
221 {
222  ListCell *lc;
223 
224  *remote_conds = NIL;
225  *local_conds = NIL;
226 
227  foreach(lc, input_conds)
228  {
229  RestrictInfo *ri = lfirst_node(RestrictInfo, lc);
230 
231  if (is_foreign_expr(root, baserel, ri->clause))
232  *remote_conds = lappend(*remote_conds, ri);
233  else
234  *local_conds = lappend(*local_conds, ri);
235  }
236 }
237 
238 /*
239  * Returns true if given expr is safe to evaluate on the foreign server.
240  */
241 bool
242 is_foreign_expr(PlannerInfo *root,
243  RelOptInfo *baserel,
244  Expr *expr)
245 {
246  foreign_glob_cxt glob_cxt;
247  foreign_loc_cxt loc_cxt;
248  PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) (baserel->fdw_private);
249 
250  /*
251  * Check that the expression consists of nodes that are safe to execute
252  * remotely.
253  */
254  glob_cxt.root = root;
255  glob_cxt.foreignrel = baserel;
256 
257  /*
258  * For an upper relation, use relids from its underneath scan relation,
259  * because the upperrel's own relids currently aren't set to anything
260  * meaningful by the core code. For other relation, use their own relids.
261  */
262  if (IS_UPPER_REL(baserel))
263  glob_cxt.relids = fpinfo->outerrel->relids;
264  else
265  glob_cxt.relids = baserel->relids;
266  loc_cxt.collation = InvalidOid;
267  loc_cxt.state = FDW_COLLATE_NONE;
268  if (!foreign_expr_walker((Node *) expr, &glob_cxt, &loc_cxt, NULL))
269  return false;
270 
271  /*
272  * If the expression has a valid collation that does not arise from a
273  * foreign var, the expression can not be sent over.
274  */
275  if (loc_cxt.state == FDW_COLLATE_UNSAFE)
276  return false;
277 
278  /*
279  * An expression which includes any mutable functions can't be sent over
280  * because its result is not stable. For example, sending now() remote
281  * side could cause confusion from clock offsets. Future versions might
282  * be able to make this choice with more granularity. (We check this last
283  * because it requires a lot of expensive catalog lookups.)
284  */
285  if (contain_mutable_functions((Node *) expr))
286  return false;
287 
288  /* OK to evaluate on the remote server */
289  return true;
290 }
291 
292 /*
293  * Check if expression is safe to execute remotely, and return true if so.
294  *
295  * In addition, *outer_cxt is updated with collation information.
296  *
297  * case_arg_cxt is NULL if this subexpression is not inside a CASE-with-arg.
298  * Otherwise, it points to the collation info derived from the arg expression,
299  * which must be consulted by any CaseTestExpr.
300  *
301  * We must check that the expression contains only node types we can deparse,
302  * that all types/functions/operators are safe to send (they are "shippable"),
303  * and that all collations used in the expression derive from Vars of the
304  * foreign table. Because of the latter, the logic is pretty close to
305  * assign_collations_walker() in parse_collate.c, though we can assume here
306  * that the given expression is valid. Note function mutability is not
307  * currently considered here.
308  */
309 static bool
310 foreign_expr_walker(Node *node,
311  foreign_glob_cxt *glob_cxt,
312  foreign_loc_cxt *outer_cxt,
313  foreign_loc_cxt *case_arg_cxt)
314 {
315  bool check_type = true;
316  PgFdwRelationInfo *fpinfo;
317  foreign_loc_cxt inner_cxt;
318  Oid collation;
319  FDWCollateState state;
320 
321  /* Need do nothing for empty subexpressions */
322  if (node == NULL)
323  return true;
324 
325  /* May need server info from baserel's fdw_private struct */
326  fpinfo = (PgFdwRelationInfo *) (glob_cxt->foreignrel->fdw_private);
327 
328  /* Set up inner_cxt for possible recursion to child nodes */
329  inner_cxt.collation = InvalidOid;
330  inner_cxt.state = FDW_COLLATE_NONE;
331 
332  switch (nodeTag(node))
333  {
334  case T_Var:
335  {
336  Var *var = (Var *) node;
337 
338  /*
339  * If the Var is from the foreign table, we consider its
340  * collation (if any) safe to use. If it is from another
341  * table, we treat its collation the same way as we would a
342  * Param's collation, ie it's not safe for it to have a
343  * non-default collation.
344  */
345  if (bms_is_member(var->varno, glob_cxt->relids) &&
346  var->varlevelsup == 0)
347  {
348  /* Var belongs to foreign table */
349 
350  /*
351  * System columns other than ctid should not be sent to
352  * the remote, since we don't make any effort to ensure
353  * that local and remote values match (tableoid, in
354  * particular, almost certainly doesn't match).
355  */
356  if (var->varattno < 0 &&
357  var->varattno != SelfItemPointerAttributeNumber)
358  return false;
359 
360  /* Else check the collation */
361  collation = var->varcollid;
362  state = OidIsValid(collation) ? FDW_COLLATE_SAFE : FDW_COLLATE_NONE;
363  }
364  else
365  {
366  /* Var belongs to some other table */
367  collation = var->varcollid;
368  if (collation == InvalidOid ||
369  collation == DEFAULT_COLLATION_OID)
370  {
371  /*
372  * It's noncollatable, or it's safe to combine with a
373  * collatable foreign Var, so set state to NONE.
374  */
375  state = FDW_COLLATE_NONE;
376  }
377  else
378  {
379  /*
380  * Do not fail right away, since the Var might appear
381  * in a collation-insensitive context.
382  */
383  state = FDW_COLLATE_UNSAFE;
384  }
385  }
386  }
387  break;
388  case T_Const:
389  {
390  Const *c = (Const *) node;
391 
392  /*
393  * Constants of regproc and related types can't be shipped
394  * unless the referenced object is shippable. But NULL's ok.
395  * (See also the related code in dependency.c.)
396  */
397  if (!c->constisnull)
398  {
399  switch (c->consttype)
400  {
401  case REGPROCOID:
402  case REGPROCEDUREOID:
403  if (!is_shippable(DatumGetObjectId(c->constvalue),
404  ProcedureRelationId, fpinfo))
405  return false;
406  break;
407  case REGOPEROID:
408  case REGOPERATOROID:
409  if (!is_shippable(DatumGetObjectId(c->constvalue),
410  OperatorRelationId, fpinfo))
411  return false;
412  break;
413  case REGCLASSOID:
414  if (!is_shippable(DatumGetObjectId(c->constvalue),
415  RelationRelationId, fpinfo))
416  return false;
417  break;
418  case REGTYPEOID:
419  if (!is_shippable(DatumGetObjectId(c->constvalue),
420  TypeRelationId, fpinfo))
421  return false;
422  break;
423  case REGCOLLATIONOID:
424  if (!is_shippable(DatumGetObjectId(c->constvalue),
425  CollationRelationId, fpinfo))
426  return false;
427  break;
428  case REGCONFIGOID:
429 
430  /*
431  * For text search objects only, we weaken the
432  * normal shippability criterion to allow all OIDs
433  * below FirstNormalObjectId. Without this, none
434  * of the initdb-installed TS configurations would
435  * be shippable, which would be quite annoying.
436  */
437  if (DatumGetObjectId(c->constvalue) >= FirstNormalObjectId &&
438  !is_shippable(DatumGetObjectId(c->constvalue),
439  TSConfigRelationId, fpinfo))
440  return false;
441  break;
442  case REGDICTIONARYOID:
443  if (DatumGetObjectId(c->constvalue) >= FirstNormalObjectId &&
444  !is_shippable(DatumGetObjectId(c->constvalue),
445  TSDictionaryRelationId, fpinfo))
446  return false;
447  break;
448  case REGNAMESPACEOID:
449  if (!is_shippable(DatumGetObjectId(c->constvalue),
450  NamespaceRelationId, fpinfo))
451  return false;
452  break;
453  case REGROLEOID:
454  if (!is_shippable(DatumGetObjectId(c->constvalue),
455  AuthIdRelationId, fpinfo))
456  return false;
457  break;
458  }
459  }
460 
461  /*
462  * If the constant has nondefault collation, either it's of a
463  * non-builtin type, or it reflects folding of a CollateExpr.
464  * It's unsafe to send to the remote unless it's used in a
465  * non-collation-sensitive context.
466  */
467  collation = c->constcollid;
468  if (collation == InvalidOid ||
469  collation == DEFAULT_COLLATION_OID)
470  state = FDW_COLLATE_NONE;
471  else
472  state = FDW_COLLATE_UNSAFE;
473  }
474  break;
475  case T_Param:
476  {
477  Param *p = (Param *) node;
478 
479  /*
480  * If it's a MULTIEXPR Param, punt. We can't tell from here
481  * whether the referenced sublink/subplan contains any remote
482  * Vars; if it does, handling that is too complicated to
483  * consider supporting at present. Fortunately, MULTIEXPR
484  * Params are not reduced to plain PARAM_EXEC until the end of
485  * planning, so we can easily detect this case. (Normal
486  * PARAM_EXEC Params are safe to ship because their values
487  * come from somewhere else in the plan tree; but a MULTIEXPR
488  * references a sub-select elsewhere in the same targetlist,
489  * so we'd be on the hook to evaluate it somehow if we wanted
490  * to handle such cases as direct foreign updates.)
491  */
492  if (p->paramkind == PARAM_MULTIEXPR)
493  return false;
494 
495  /*
496  * Collation rule is same as for Consts and non-foreign Vars.
497  */
498  collation = p->paramcollid;
499  if (collation == InvalidOid ||
500  collation == DEFAULT_COLLATION_OID)
501  state = FDW_COLLATE_NONE;
502  else
503  state = FDW_COLLATE_UNSAFE;
504  }
505  break;
506  case T_SubscriptingRef:
507  {
508  SubscriptingRef *sr = (SubscriptingRef *) node;
509 
510  /* Assignment should not be in restrictions. */
511  if (sr->refassgnexpr != NULL)
512  return false;
513 
514  /*
515  * Recurse into the remaining subexpressions. The container
516  * subscripts will not affect collation of the SubscriptingRef
517  * result, so do those first and reset inner_cxt afterwards.
518  */
519  if (!foreign_expr_walker((Node *) sr->refupperindexpr,
520  glob_cxt, &inner_cxt, case_arg_cxt))
521  return false;
522  inner_cxt.collation = InvalidOid;
523  inner_cxt.state = FDW_COLLATE_NONE;
524  if (!foreign_expr_walker((Node *) sr->reflowerindexpr,
525  glob_cxt, &inner_cxt, case_arg_cxt))
526  return false;
527  inner_cxt.collation = InvalidOid;
528  inner_cxt.state = FDW_COLLATE_NONE;
529  if (!foreign_expr_walker((Node *) sr->refexpr,
530  glob_cxt, &inner_cxt, case_arg_cxt))
531  return false;
532 
533  /*
534  * Container subscripting typically yields same collation as
535  * refexpr's, but in case it doesn't, use same logic as for
536  * function nodes.
537  */
538  collation = sr->refcollid;
539  if (collation == InvalidOid)
540  state = FDW_COLLATE_NONE;
541  else if (inner_cxt.state == FDW_COLLATE_SAFE &&
542  collation == inner_cxt.collation)
543  state = FDW_COLLATE_SAFE;
544  else if (collation == DEFAULT_COLLATION_OID)
545  state = FDW_COLLATE_NONE;
546  else
547  state = FDW_COLLATE_UNSAFE;
548  }
549  break;
550  case T_FuncExpr:
551  {
552  FuncExpr *fe = (FuncExpr *) node;
553 
554  /*
555  * If function used by the expression is not shippable, it
556  * can't be sent to remote because it might have incompatible
557  * semantics on remote side.
558  */
559  if (!is_shippable(fe->funcid, ProcedureRelationId, fpinfo))
560  return false;
561 
562  /*
563  * Recurse to input subexpressions.
564  */
565  if (!foreign_expr_walker((Node *) fe->args,
566  glob_cxt, &inner_cxt, case_arg_cxt))
567  return false;
568 
569  /*
570  * If function's input collation is not derived from a foreign
571  * Var, it can't be sent to remote.
572  */
573  if (fe->inputcollid == InvalidOid)
574  /* OK, inputs are all noncollatable */ ;
575  else if (inner_cxt.state != FDW_COLLATE_SAFE ||
576  fe->inputcollid != inner_cxt.collation)
577  return false;
578 
579  /*
580  * Detect whether node is introducing a collation not derived
581  * from a foreign Var. (If so, we just mark it unsafe for now
582  * rather than immediately returning false, since the parent
583  * node might not care.)
584  */
585  collation = fe->funccollid;
586  if (collation == InvalidOid)
587  state = FDW_COLLATE_NONE;
588  else if (inner_cxt.state == FDW_COLLATE_SAFE &&
589  collation == inner_cxt.collation)
590  state = FDW_COLLATE_SAFE;
591  else if (collation == DEFAULT_COLLATION_OID)
592  state = FDW_COLLATE_NONE;
593  else
594  state = FDW_COLLATE_UNSAFE;
595  }
596  break;
597  case T_OpExpr:
598  case T_DistinctExpr: /* struct-equivalent to OpExpr */
599  {
600  OpExpr *oe = (OpExpr *) node;
601 
602  /*
603  * Similarly, only shippable operators can be sent to remote.
604  * (If the operator is shippable, we assume its underlying
605  * function is too.)
606  */
607  if (!is_shippable(oe->opno, OperatorRelationId, fpinfo))
608  return false;
609 
610  /*
611  * Recurse to input subexpressions.
612  */
613  if (!foreign_expr_walker((Node *) oe->args,
614  glob_cxt, &inner_cxt, case_arg_cxt))
615  return false;
616 
617  /*
618  * If operator's input collation is not derived from a foreign
619  * Var, it can't be sent to remote.
620  */
621  if (oe->inputcollid == InvalidOid)
622  /* OK, inputs are all noncollatable */ ;
623  else if (inner_cxt.state != FDW_COLLATE_SAFE ||
624  oe->inputcollid != inner_cxt.collation)
625  return false;
626 
627  /* Result-collation handling is same as for functions */
628  collation = oe->opcollid;
629  if (collation == InvalidOid)
630  state = FDW_COLLATE_NONE;
631  else if (inner_cxt.state == FDW_COLLATE_SAFE &&
632  collation == inner_cxt.collation)
633  state = FDW_COLLATE_SAFE;
634  else if (collation == DEFAULT_COLLATION_OID)
635  state = FDW_COLLATE_NONE;
636  else
637  state = FDW_COLLATE_UNSAFE;
638  }
639  break;
640  case T_ScalarArrayOpExpr:
641  {
642  ScalarArrayOpExpr *oe = (ScalarArrayOpExpr *) node;
643 
644  /*
645  * Again, only shippable operators can be sent to remote.
646  */
647  if (!is_shippable(oe->opno, OperatorRelationId, fpinfo))
648  return false;
649 
650  /*
651  * Recurse to input subexpressions.
652  */
653  if (!foreign_expr_walker((Node *) oe->args,
654  glob_cxt, &inner_cxt, case_arg_cxt))
655  return false;
656 
657  /*
658  * If operator's input collation is not derived from a foreign
659  * Var, it can't be sent to remote.
660  */
661  if (oe->inputcollid == InvalidOid)
662  /* OK, inputs are all noncollatable */ ;
663  else if (inner_cxt.state != FDW_COLLATE_SAFE ||
664  oe->inputcollid != inner_cxt.collation)
665  return false;
666 
667  /* Output is always boolean and so noncollatable. */
668  collation = InvalidOid;
669  state = FDW_COLLATE_NONE;
670  }
671  break;
672  case T_RelabelType:
673  {
674  RelabelType *r = (RelabelType *) node;
675 
676  /*
677  * Recurse to input subexpression.
678  */
679  if (!foreign_expr_walker((Node *) r->arg,
680  glob_cxt, &inner_cxt, case_arg_cxt))
681  return false;
682 
683  /*
684  * RelabelType must not introduce a collation not derived from
685  * an input foreign Var (same logic as for a real function).
686  */
687  collation = r->resultcollid;
688  if (collation == InvalidOid)
689  state = FDW_COLLATE_NONE;
690  else if (inner_cxt.state == FDW_COLLATE_SAFE &&
691  collation == inner_cxt.collation)
692  state = FDW_COLLATE_SAFE;
693  else if (collation == DEFAULT_COLLATION_OID)
694  state = FDW_COLLATE_NONE;
695  else
696  state = FDW_COLLATE_UNSAFE;
697  }
698  break;
699  case T_BoolExpr:
700  {
701  BoolExpr *b = (BoolExpr *) node;
702 
703  /*
704  * Recurse to input subexpressions.
705  */
706  if (!foreign_expr_walker((Node *) b->args,
707  glob_cxt, &inner_cxt, case_arg_cxt))
708  return false;
709 
710  /* Output is always boolean and so noncollatable. */
711  collation = InvalidOid;
712  state = FDW_COLLATE_NONE;
713  }
714  break;
715  case T_NullTest:
716  {
717  NullTest *nt = (NullTest *) node;
718 
719  /*
720  * Recurse to input subexpressions.
721  */
722  if (!foreign_expr_walker((Node *) nt->arg,
723  glob_cxt, &inner_cxt, case_arg_cxt))
724  return false;
725 
726  /* Output is always boolean and so noncollatable. */
727  collation = InvalidOid;
728  state = FDW_COLLATE_NONE;
729  }
730  break;
731  case T_CaseExpr:
732  {
733  CaseExpr *ce = (CaseExpr *) node;
734  foreign_loc_cxt arg_cxt;
735  foreign_loc_cxt tmp_cxt;
736  ListCell *lc;
737 
738  /*
739  * Recurse to CASE's arg expression, if any. Its collation
740  * has to be saved aside for use while examining CaseTestExprs
741  * within the WHEN expressions.
742  */
743  arg_cxt.collation = InvalidOid;
744  arg_cxt.state = FDW_COLLATE_NONE;
745  if (ce->arg)
746  {
747  if (!foreign_expr_walker((Node *) ce->arg,
748  glob_cxt, &arg_cxt, case_arg_cxt))
749  return false;
750  }
751 
752  /* Examine the CaseWhen subexpressions. */
753  foreach(lc, ce->args)
754  {
755  CaseWhen *cw = lfirst_node(CaseWhen, lc);
756 
757  if (ce->arg)
758  {
759  /*
760  * In a CASE-with-arg, the parser should have produced
761  * WHEN clauses of the form "CaseTestExpr = RHS",
762  * possibly with an implicit coercion inserted above
763  * the CaseTestExpr. However in an expression that's
764  * been through the optimizer, the WHEN clause could
765  * be almost anything (since the equality operator
766  * could have been expanded into an inline function).
767  * In such cases forbid pushdown, because
768  * deparseCaseExpr can't handle it.
769  */
770  Node *whenExpr = (Node *) cw->expr;
771  List *opArgs;
772 
773  if (!IsA(whenExpr, OpExpr))
774  return false;
775 
776  opArgs = ((OpExpr *) whenExpr)->args;
777  if (list_length(opArgs) != 2 ||
778  !IsA(strip_implicit_coercions(linitial(opArgs)),
779  CaseTestExpr))
780  return false;
781  }
782 
783  /*
784  * Recurse to WHEN expression, passing down the arg info.
785  * Its collation doesn't affect the result (really, it
786  * should be boolean and thus not have a collation).
787  */
788  tmp_cxt.collation = InvalidOid;
789  tmp_cxt.state = FDW_COLLATE_NONE;
790  if (!foreign_expr_walker((Node *) cw->expr,
791  glob_cxt, &tmp_cxt, &arg_cxt))
792  return false;
793 
794  /* Recurse to THEN expression. */
795  if (!foreign_expr_walker((Node *) cw->result,
796  glob_cxt, &inner_cxt, case_arg_cxt))
797  return false;
798  }
799 
800  /* Recurse to ELSE expression. */
801  if (!foreign_expr_walker((Node *) ce->defresult,
802  glob_cxt, &inner_cxt, case_arg_cxt))
803  return false;
804 
805  /*
806  * Detect whether node is introducing a collation not derived
807  * from a foreign Var. (If so, we just mark it unsafe for now
808  * rather than immediately returning false, since the parent
809  * node might not care.) This is the same as for function
810  * nodes, except that the input collation is derived from only
811  * the THEN and ELSE subexpressions.
812  */
813  collation = ce->casecollid;
814  if (collation == InvalidOid)
815  state = FDW_COLLATE_NONE;
816  else if (inner_cxt.state == FDW_COLLATE_SAFE &&
817  collation == inner_cxt.collation)
818  state = FDW_COLLATE_SAFE;
819  else if (collation == DEFAULT_COLLATION_OID)
820  state = FDW_COLLATE_NONE;
821  else
822  state = FDW_COLLATE_UNSAFE;
823  }
824  break;
825  case T_CaseTestExpr:
826  {
827  CaseTestExpr *c = (CaseTestExpr *) node;
828 
829  /* Punt if we seem not to be inside a CASE arg WHEN. */
830  if (!case_arg_cxt)
831  return false;
832 
833  /*
834  * Otherwise, any nondefault collation attached to the
835  * CaseTestExpr node must be derived from foreign Var(s) in
836  * the CASE arg.
837  */
838  collation = c->collation;
839  if (collation == InvalidOid)
840  state = FDW_COLLATE_NONE;
841  else if (case_arg_cxt->state == FDW_COLLATE_SAFE &&
842  collation == case_arg_cxt->collation)
843  state = FDW_COLLATE_SAFE;
844  else if (collation == DEFAULT_COLLATION_OID)
845  state = FDW_COLLATE_NONE;
846  else
847  state = FDW_COLLATE_UNSAFE;
848  }
849  break;
850  case T_ArrayExpr:
851  {
852  ArrayExpr *a = (ArrayExpr *) node;
853 
854  /*
855  * Recurse to input subexpressions.
856  */
857  if (!foreign_expr_walker((Node *) a->elements,
858  glob_cxt, &inner_cxt, case_arg_cxt))
859  return false;
860 
861  /*
862  * ArrayExpr must not introduce a collation not derived from
863  * an input foreign Var (same logic as for a function).
864  */
865  collation = a->array_collid;
866  if (collation == InvalidOid)
867  state = FDW_COLLATE_NONE;
868  else if (inner_cxt.state == FDW_COLLATE_SAFE &&
869  collation == inner_cxt.collation)
870  state = FDW_COLLATE_SAFE;
871  else if (collation == DEFAULT_COLLATION_OID)
872  state = FDW_COLLATE_NONE;
873  else
874  state = FDW_COLLATE_UNSAFE;
875  }
876  break;
877  case T_List:
878  {
879  List *l = (List *) node;
880  ListCell *lc;
881 
882  /*
883  * Recurse to component subexpressions.
884  */
885  foreach(lc, l)
886  {
887  if (!foreign_expr_walker((Node *) lfirst(lc),
888  glob_cxt, &inner_cxt, case_arg_cxt))
889  return false;
890  }
891 
892  /*
893  * When processing a list, collation state just bubbles up
894  * from the list elements.
895  */
896  collation = inner_cxt.collation;
897  state = inner_cxt.state;
898 
899  /* Don't apply exprType() to the list. */
900  check_type = false;
901  }
902  break;
903  case T_Aggref:
904  {
905  Aggref *agg = (Aggref *) node;
906  ListCell *lc;
907 
908  /* Not safe to pushdown when not in grouping context */
909  if (!IS_UPPER_REL(glob_cxt->foreignrel))
910  return false;
911 
912  /* Only non-split aggregates are pushable. */
913  if (agg->aggsplit != AGGSPLIT_SIMPLE)
914  return false;
915 
916  /* As usual, it must be shippable. */
917  if (!is_shippable(agg->aggfnoid, ProcedureRelationId, fpinfo))
918  return false;
919 
920  /*
921  * Recurse to input args. aggdirectargs, aggorder and
922  * aggdistinct are all present in args, so no need to check
923  * their shippability explicitly.
924  */
925  foreach(lc, agg->args)
926  {
927  Node *n = (Node *) lfirst(lc);
928 
929  /* If TargetEntry, extract the expression from it */
930  if (IsA(n, TargetEntry))
931  {
932  TargetEntry *tle = (TargetEntry *) n;
933 
934  n = (Node *) tle->expr;
935  }
936 
937  if (!foreign_expr_walker(n,
938  glob_cxt, &inner_cxt, case_arg_cxt))
939  return false;
940  }
941 
942  /*
943  * For aggorder elements, check whether the sort operator, if
944  * specified, is shippable or not.
945  */
946  if (agg->aggorder)
947  {
948  foreach(lc, agg->aggorder)
949  {
950  SortGroupClause *srt = (SortGroupClause *) lfirst(lc);
951  Oid sortcoltype;
952  TypeCacheEntry *typentry;
953  TargetEntry *tle;
954 
955  tle = get_sortgroupref_tle(srt->tleSortGroupRef,
956  agg->args);
957  sortcoltype = exprType((Node *) tle->expr);
958  typentry = lookup_type_cache(sortcoltype,
959  TYPECACHE_LT_OPR | TYPECACHE_GT_OPR);
960  /* Check shippability of non-default sort operator. */
961  if (srt->sortop != typentry->lt_opr &&
962  srt->sortop != typentry->gt_opr &&
963  !is_shippable(srt->sortop, OperatorRelationId,
964  fpinfo))
965  return false;
966  }
967  }
968 
969  /* Check aggregate filter */
970  if (!foreign_expr_walker((Node *) agg->aggfilter,
971  glob_cxt, &inner_cxt, case_arg_cxt))
972  return false;
973 
974  /*
975  * If aggregate's input collation is not derived from a
976  * foreign Var, it can't be sent to remote.
977  */
978  if (agg->inputcollid == InvalidOid)
979  /* OK, inputs are all noncollatable */ ;
980  else if (inner_cxt.state != FDW_COLLATE_SAFE ||
981  agg->inputcollid != inner_cxt.collation)
982  return false;
983 
984  /*
985  * Detect whether node is introducing a collation not derived
986  * from a foreign Var. (If so, we just mark it unsafe for now
987  * rather than immediately returning false, since the parent
988  * node might not care.)
989  */
990  collation = agg->aggcollid;
991  if (collation == InvalidOid)
992  state = FDW_COLLATE_NONE;
993  else if (inner_cxt.state == FDW_COLLATE_SAFE &&
994  collation == inner_cxt.collation)
995  state = FDW_COLLATE_SAFE;
996  else if (collation == DEFAULT_COLLATION_OID)
997  state = FDW_COLLATE_NONE;
998  else
999  state = FDW_COLLATE_UNSAFE;
1000  }
1001  break;
1002  default:
1003 
1004  /*
1005  * If it's anything else, assume it's unsafe. This list can be
1006  * expanded later, but don't forget to add deparse support below.
1007  */
1008  return false;
1009  }
1010 
1011  /*
1012  * If result type of given expression is not shippable, it can't be sent
1013  * to remote because it might have incompatible semantics on remote side.
1014  */
1015  if (check_type && !is_shippable(exprType(node), TypeRelationId, fpinfo))
1016  return false;
1017 
1018  /*
1019  * Now, merge my collation information into my parent's state.
1020  */
1021  if (state > outer_cxt->state)
1022  {
1023  /* Override previous parent state */
1024  outer_cxt->collation = collation;
1025  outer_cxt->state = state;
1026  }
1027  else if (state == outer_cxt->state)
1028  {
1029  /* Merge, or detect error if there's a collation conflict */
1030  switch (state)
1031  {
1032  case FDW_COLLATE_NONE:
1033  /* Nothing + nothing is still nothing */
1034  break;
1035  case FDW_COLLATE_SAFE:
1036  if (collation != outer_cxt->collation)
1037  {
1038  /*
1039  * Non-default collation always beats default.
1040  */
1041  if (outer_cxt->collation == DEFAULT_COLLATION_OID)
1042  {
1043  /* Override previous parent state */
1044  outer_cxt->collation = collation;
1045  }
1046  else if (collation != DEFAULT_COLLATION_OID)
1047  {
1048  /*
1049  * Conflict; show state as indeterminate. We don't
1050  * want to "return false" right away, since parent
1051  * node might not care about collation.
1052  */
1053  outer_cxt->state = FDW_COLLATE_UNSAFE;
1054  }
1055  }
1056  break;
1057  case FDW_COLLATE_UNSAFE:
1058  /* We're still conflicted ... */
1059  break;
1060  }
1061  }
1062 
1063  /* It looks OK */
1064  return true;
1065 }
1066 
1067 /*
1068  * Returns true if given expr is something we'd have to send the value of
1069  * to the foreign server.
1070  *
1071  * This should return true when the expression is a shippable node that
1072  * deparseExpr would add to context->params_list. Note that we don't care
1073  * if the expression *contains* such a node, only whether one appears at top
1074  * level. We need this to detect cases where setrefs.c would recognize a
1075  * false match between an fdw_exprs item (which came from the params_list)
1076  * and an entry in fdw_scan_tlist (which we're considering putting the given
1077  * expression into).
1078  */
1079 bool
1080 is_foreign_param(PlannerInfo *root,
1081  RelOptInfo *baserel,
1082  Expr *expr)
1083 {
1084  if (expr == NULL)
1085  return false;
1086 
1087  switch (nodeTag(expr))
1088  {
1089  case T_Var:
1090  {
1091  /* It would have to be sent unless it's a foreign Var */
1092  Var *var = (Var *) expr;
1093  PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) (baserel->fdw_private);
1094  Relids relids;
1095 
1096  if (IS_UPPER_REL(baserel))
1097  relids = fpinfo->outerrel->relids;
1098  else
1099  relids = baserel->relids;
1100 
1101  if (bms_is_member(var->varno, relids) && var->varlevelsup == 0)
1102  return false; /* foreign Var, so not a param */
1103  else
1104  return true; /* it'd have to be a param */
1105  break;
1106  }
1107  case T_Param:
1108  /* Params always have to be sent to the foreign server */
1109  return true;
1110  default:
1111  break;
1112  }
1113  return false;
1114 }
1115 
1116 /*
1117  * Returns true if it's safe to push down the sort expression described by
1118  * 'pathkey' to the foreign server.
1119  */
1120 bool
1121 is_foreign_pathkey(PlannerInfo *root,
1122  RelOptInfo *baserel,
1123  PathKey *pathkey)
1124 {
1125  EquivalenceClass *pathkey_ec = pathkey->pk_eclass;
1126  PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) baserel->fdw_private;
1127 
1128  /*
1129  * is_foreign_expr would detect volatile expressions as well, but checking
1130  * ec_has_volatile here saves some cycles.
1131  */
1132  if (pathkey_ec->ec_has_volatile)
1133  return false;
1134 
1135  /* can't push down the sort if the pathkey's opfamily is not shippable */
1136  if (!is_shippable(pathkey->pk_opfamily, OperatorFamilyRelationId, fpinfo))
1137  return false;
1138 
1139  /* can push if a suitable EC member exists */
1140  return (find_em_for_rel(root, pathkey_ec, baserel) != NULL);
1141 }
1142 
1143 /*
1144  * Convert type OID + typmod info into a type name we can ship to the remote
1145  * server. Someplace else had better have verified that this type name is
1146  * expected to be known on the remote end.
1147  *
1148  * This is almost just format_type_with_typemod(), except that if left to its
1149  * own devices, that function will make schema-qualification decisions based
1150  * on the local search_path, which is wrong. We must schema-qualify all
1151  * type names that are not in pg_catalog. We assume here that built-in types
1152  * are all in pg_catalog and need not be qualified; otherwise, qualify.
1153  */
1154 static char *
1155 deparse_type_name(Oid type_oid, int32 typemod)
1156 {
1157  bits16 flags = FORMAT_TYPE_TYPEMOD_GIVEN;
1158 
1159  if (!is_builtin(type_oid))
1160  flags |= FORMAT_TYPE_FORCE_QUALIFY;
1161 
1162  return format_type_extended(type_oid, typemod, flags);
1163 }
1164 
1165 /*
1166  * Build the targetlist for given relation to be deparsed as SELECT clause.
1167  *
1168  * The output targetlist contains the columns that need to be fetched from the
1169  * foreign server for the given relation. If foreignrel is an upper relation,
1170  * then the output targetlist can also contain expressions to be evaluated on
1171  * foreign server.
1172  */
1173 List *
1174 build_tlist_to_deparse(RelOptInfo *foreignrel)
1175 {
1176  List *tlist = NIL;
1177  PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1178  ListCell *lc;
1179 
1180  /*
1181  * For an upper relation, we have already built the target list while
1182  * checking shippability, so just return that.
1183  */
1184  if (IS_UPPER_REL(foreignrel))
1185  return fpinfo->grouped_tlist;
1186 
1187  /*
1188  * We require columns specified in foreignrel->reltarget->exprs and those
1189  * required for evaluating the local conditions.
1190  */
1191  tlist = add_to_flat_tlist(tlist,
1192  pull_var_clause((Node *) foreignrel->reltarget->exprs,
1193  PVC_RECURSE_PLACEHOLDERS));
1194  foreach(lc, fpinfo->local_conds)
1195  {
1196  RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
1197 
1198  tlist = add_to_flat_tlist(tlist,
1199  pull_var_clause((Node *) rinfo->clause,
1200  PVC_RECURSE_PLACEHOLDERS));
1201  }
1202 
1203  return tlist;
1204 }
1205 
1206 /*
1207  * Deparse SELECT statement for given relation into buf.
1208  *
1209  * tlist contains the list of desired columns to be fetched from foreign server.
1210  * For a base relation fpinfo->attrs_used is used to construct SELECT clause,
1211  * hence the tlist is ignored for a base relation.
1212  *
1213  * remote_conds is the list of conditions to be deparsed into the WHERE clause
1214  * (or, in the case of upper relations, into the HAVING clause).
1215  *
1216  * If params_list is not NULL, it receives a list of Params and other-relation
1217  * Vars used in the clauses; these values must be transmitted to the remote
1218  * server as parameter values.
1219  *
1220  * If params_list is NULL, we're generating the query for EXPLAIN purposes,
1221  * so Params and other-relation Vars should be replaced by dummy values.
1222  *
1223  * pathkeys is the list of pathkeys to order the result by.
1224  *
1225  * is_subquery is the flag to indicate whether to deparse the specified
1226  * relation as a subquery.
1227  *
1228  * List of columns selected is returned in retrieved_attrs.
1229  */
1230 void
1231 deparseSelectStmtForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *rel,
1232  List *tlist, List *remote_conds, List *pathkeys,
1233  bool has_final_sort, bool has_limit, bool is_subquery,
1234  List **retrieved_attrs, List **params_list)
1235 {
1236  deparse_expr_cxt context;
1237  PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) rel->fdw_private;
1238  List *quals;
1239 
1240  /*
1241  * We handle relations for foreign tables, joins between those and upper
1242  * relations.
1243  */
1244  Assert(IS_JOIN_REL(rel) || IS_SIMPLE_REL(rel) || IS_UPPER_REL(rel));
1245 
1246  /* Fill portions of context common to upper, join and base relation */
1247  context.buf = buf;
1248  context.root = root;
1249  context.foreignrel = rel;
1250  context.scanrel = IS_UPPER_REL(rel) ? fpinfo->outerrel : rel;
1251  context.params_list = params_list;
1252 
1253  /* Construct SELECT clause */
1254  deparseSelectSql(tlist, is_subquery, retrieved_attrs, &context);
1255 
1256  /*
1257  * For upper relations, the WHERE clause is built from the remote
1258  * conditions of the underlying scan relation; otherwise, we can use the
1259  * supplied list of remote conditions directly.
1260  */
1261  if (IS_UPPER_REL(rel))
1262  {
1263  PgFdwRelationInfo *ofpinfo;
1264 
1265  ofpinfo = (PgFdwRelationInfo *) fpinfo->outerrel->fdw_private;
1266  quals = ofpinfo->remote_conds;
1267  }
1268  else
1269  quals = remote_conds;
1270 
1271  /* Construct FROM and WHERE clauses */
1272  deparseFromExpr(quals, &context);
1273 
1274  if (IS_UPPER_REL(rel))
1275  {
1276  /* Append GROUP BY clause */
1277  appendGroupByClause(tlist, &context);
1278 
1279  /* Append HAVING clause */
1280  if (remote_conds)
1281  {
1282  appendStringInfoString(buf, " HAVING ");
1283  appendConditions(remote_conds, &context);
1284  }
1285  }
1286 
1287  /* Add ORDER BY clause if we found any useful pathkeys */
1288  if (pathkeys)
1289  appendOrderByClause(pathkeys, has_final_sort, &context);
1290 
1291  /* Add LIMIT clause if necessary */
1292  if (has_limit)
1293  appendLimitClause(&context);
1294 
1295  /* Add any necessary FOR UPDATE/SHARE. */
1296  deparseLockingClause(&context);
1297 }
1298 
1299 /*
1300  * Construct a simple SELECT statement that retrieves desired columns
1301  * of the specified foreign table, and append it to "buf". The output
1302  * contains just "SELECT ... ".
1303  *
1304  * We also create an integer List of the columns being retrieved, which is
1305  * returned to *retrieved_attrs, unless we deparse the specified relation
1306  * as a subquery.
1307  *
1308  * tlist is the list of desired columns. is_subquery is the flag to
1309  * indicate whether to deparse the specified relation as a subquery.
1310  * Read prologue of deparseSelectStmtForRel() for details.
1311  */
1312 static void
1313 deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_attrs,
1314  deparse_expr_cxt *context)
1315 {
1316  StringInfo buf = context->buf;
1317  RelOptInfo *foreignrel = context->foreignrel;
1318  PlannerInfo *root = context->root;
1319  PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1320 
1321  /*
1322  * Construct SELECT list
1323  */
1324  appendStringInfoString(buf, "SELECT ");
1325 
1326  if (is_subquery)
1327  {
1328  /*
1329  * For a relation that is deparsed as a subquery, emit expressions
1330  * specified in the relation's reltarget. Note that since this is for
1331  * the subquery, no need to care about *retrieved_attrs.
1332  */
1333  deparseSubqueryTargetList(context);
1334  }
1335  else if (IS_JOIN_REL(foreignrel) || IS_UPPER_REL(foreignrel))
1336  {
1337  /*
1338  * For a join or upper relation the input tlist gives the list of
1339  * columns required to be fetched from the foreign server.
1340  */
1341  deparseExplicitTargetList(tlist, false, retrieved_attrs, context);
1342  }
1343  else
1344  {
1345  /*
1346  * For a base relation fpinfo->attrs_used gives the list of columns
1347  * required to be fetched from the foreign server.
1348  */
1349  RangeTblEntry *rte = planner_rt_fetch(foreignrel->relid, root);
1350 
1351  /*
1352  * Core code already has some lock on each rel being planned, so we
1353  * can use NoLock here.
1354  */
1355  Relation rel = table_open(rte->relid, NoLock);
1356 
1357  deparseTargetList(buf, rte, foreignrel->relid, rel, false,
1358  fpinfo->attrs_used, false, retrieved_attrs);
1359  table_close(rel, NoLock);
1360  }
1361 }
1362 
1363 /*
1364  * Construct a FROM clause and, if needed, a WHERE clause, and append those to
1365  * "buf".
1366  *
1367  * quals is the list of clauses to be included in the WHERE clause.
1368  * (These may or may not include RestrictInfo decoration.)
1369  */
1370 static void
1371 deparseFromExpr(List *quals, deparse_expr_cxt *context)
1372 {
1373  StringInfo buf = context->buf;
1374  RelOptInfo *scanrel = context->scanrel;
1375  List *additional_conds = NIL;
1376 
1377  /* For upper relations, scanrel must be either a joinrel or a baserel */
1378  Assert(!IS_UPPER_REL(context->foreignrel) ||
1379  IS_JOIN_REL(scanrel) || IS_SIMPLE_REL(scanrel));
1380 
1381  /* Construct FROM clause */
1382  appendStringInfoString(buf, " FROM ");
1383  deparseFromExprForRel(buf, context->root, scanrel,
1384  (bms_membership(scanrel->relids) == BMS_MULTIPLE),
1385  (Index) 0, NULL, &additional_conds,
1386  context->params_list);
1387  appendWhereClause(quals, additional_conds, context);
1388  if (additional_conds != NIL)
1389  list_free_deep(additional_conds);
1390 }
1391 
1392 /*
1393  * Emit a target list that retrieves the columns specified in attrs_used.
1394  * This is used for both SELECT and RETURNING targetlists; the is_returning
1395  * parameter is true only for a RETURNING targetlist.
1396  *
1397  * The tlist text is appended to buf, and we also create an integer List
1398  * of the columns being retrieved, which is returned to *retrieved_attrs.
1399  *
1400  * If qualify_col is true, add relation alias before the column name.
1401  */
1402 static void
1403 deparseTargetList(StringInfo buf,
1404  RangeTblEntry *rte,
1405  Index rtindex,
1406  Relation rel,
1407  bool is_returning,
1408  Bitmapset *attrs_used,
1409  bool qualify_col,
1410  List **retrieved_attrs)
1411 {
1412  TupleDesc tupdesc = RelationGetDescr(rel);
1413  bool have_wholerow;
1414  bool first;
1415  int i;
1416 
1417  *retrieved_attrs = NIL;
1418 
1419  /* If there's a whole-row reference, we'll need all the columns. */
1420  have_wholerow = bms_is_member(0 - FirstLowInvalidHeapAttributeNumber,
1421  attrs_used);
1422 
1423  first = true;
1424  for (i = 1; i <= tupdesc->natts; i++)
1425  {
1426  Form_pg_attribute attr = TupleDescAttr(tupdesc, i - 1);
1427 
1428  /* Ignore dropped attributes. */
1429  if (attr->attisdropped)
1430  continue;
1431 
1432  if (have_wholerow ||
1433  bms_is_member(i - FirstLowInvalidHeapAttributeNumber,
1434  attrs_used))
1435  {
1436  if (!first)
1437  appendStringInfoString(buf, ", ");
1438  else if (is_returning)
1439  appendStringInfoString(buf, " RETURNING ");
1440  first = false;
1441 
1442  deparseColumnRef(buf, rtindex, i, rte, qualify_col);
1443 
1444  *retrieved_attrs = lappend_int(*retrieved_attrs, i);
1445  }
1446  }
1447 
1448  /*
1449  * Add ctid if needed. We currently don't support retrieving any other
1450  * system columns.
1451  */
1452  if (bms_is_member(SelfItemPointerAttributeNumber - FirstLowInvalidHeapAttributeNumber,
1453  attrs_used))
1454  {
1455  if (!first)
1456  appendStringInfoString(buf, ", ");
1457  else if (is_returning)
1458  appendStringInfoString(buf, " RETURNING ");
1459  first = false;
1460 
1461  if (qualify_col)
1462  ADD_REL_QUALIFIER(buf, rtindex);
1463  appendStringInfoString(buf, "ctid");
1464 
1465  *retrieved_attrs = lappend_int(*retrieved_attrs,
1466  SelfItemPointerAttributeNumber);
1467  }
1468 
1469  /* Don't generate bad syntax if no undropped columns */
1470  if (first && !is_returning)
1471  appendStringInfoString(buf, "NULL");
1472 }
1473 
1474 /*
1475  * Deparse the appropriate locking clause (FOR UPDATE or FOR SHARE) for a
1476  * given relation (context->scanrel).
1477  */
1478 static void
1479 deparseLockingClause(deparse_expr_cxt *context)
1480 {
1481  StringInfo buf = context->buf;
1482  PlannerInfo *root = context->root;
1483  RelOptInfo *rel = context->scanrel;
1484  PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) rel->fdw_private;
1485  int relid = -1;
1486 
1487  while ((relid = bms_next_member(rel->relids, relid)) >= 0)
1488  {
1489  /*
1490  * Ignore relation if it appears in a lower subquery. Locking clause
1491  * for such a relation is included in the subquery if necessary.
1492  */
1493  if (bms_is_member(relid, fpinfo->lower_subquery_rels))
1494  continue;
1495 
1496  /*
1497  * Add FOR UPDATE/SHARE if appropriate. We apply locking during the
1498  * initial row fetch, rather than later on as is done for local
1499  * tables. The extra roundtrips involved in trying to duplicate the
1500  * local semantics exactly don't seem worthwhile (see also comments
1501  * for RowMarkType).
1502  *
1503  * Note: because we actually run the query as a cursor, this assumes
1504  * that DECLARE CURSOR ... FOR UPDATE is supported, which it isn't
1505  * before 8.3.
1506  */
1507  if (bms_is_member(relid, root->all_result_relids) &&
1508  (root->parse->commandType == CMD_UPDATE ||
1509  root->parse->commandType == CMD_DELETE))
1510  {
1511  /* Relation is UPDATE/DELETE target, so use FOR UPDATE */
1512  appendStringInfoString(buf, " FOR UPDATE");
1513 
1514  /* Add the relation alias if we are here for a join relation */
1515  if (IS_JOIN_REL(rel))
1516  appendStringInfo(buf, " OF %s%d", REL_ALIAS_PREFIX, relid);
1517  }
1518  else
1519  {
1520  PlanRowMark *rc = get_plan_rowmark(root->rowMarks, relid);
1521 
1522  if (rc)
1523  {
1524  /*
1525  * Relation is specified as a FOR UPDATE/SHARE target, so
1526  * handle that. (But we could also see LCS_NONE, meaning this
1527  * isn't a target relation after all.)
1528  *
1529  * For now, just ignore any [NO] KEY specification, since (a)
1530  * it's not clear what that means for a remote table that we
1531  * don't have complete information about, and (b) it wouldn't
1532  * work anyway on older remote servers. Likewise, we don't
1533  * worry about NOWAIT.
1534  */
1535  switch (rc->strength)
1536  {
1537  case LCS_NONE:
1538  /* No locking needed */
1539  break;
1540  case LCS_FORKEYSHARE:
1541  case LCS_FORSHARE:
1542  appendStringInfoString(buf, " FOR SHARE");
1543  break;
1544  case LCS_FORNOKEYUPDATE:
1545  case LCS_FORUPDATE:
1546  appendStringInfoString(buf, " FOR UPDATE");
1547  break;
1548  }
1549 
1550  /* Add the relation alias if we are here for a join relation */
1551  if (bms_membership(rel->relids) == BMS_MULTIPLE &&
1552  rc->strength != LCS_NONE)
1553  appendStringInfo(buf, " OF %s%d", REL_ALIAS_PREFIX, relid);
1554  }
1555  }
1556  }
1557 }
1558 
1559 /*
1560  * Deparse conditions from the provided list and append them to buf.
1561  *
1562  * The conditions in the list are assumed to be ANDed. This function is used to
1563  * deparse WHERE clauses, JOIN .. ON clauses and HAVING clauses.
1564  *
1565  * Depending on the caller, the list elements might be either RestrictInfos
1566  * or bare clauses.
1567  */
1568 static void
1569 appendConditions(List *exprs, deparse_expr_cxt *context)
1570 {
1571  int nestlevel;
1572  ListCell *lc;
1573  bool is_first = true;
1574  StringInfo buf = context->buf;
1575 
1576  /* Make sure any constants in the exprs are printed portably */
1577  nestlevel = set_transmission_modes();
1578 
1579  foreach(lc, exprs)
1580  {
1581  Expr *expr = (Expr *) lfirst(lc);
1582 
1583  /* Extract clause from RestrictInfo, if required */
1584  if (IsA(expr, RestrictInfo))
1585  expr = ((RestrictInfo *) expr)->clause;
1586 
1587  /* Connect expressions with "AND" and parenthesize each condition. */
1588  if (!is_first)
1589  appendStringInfoString(buf, " AND ");
1590 
1591  appendStringInfoChar(buf, '(');
1592  deparseExpr(expr, context);
1593  appendStringInfoChar(buf, ')');
1594 
1595  is_first = false;
1596  }
1597 
1598  reset_transmission_modes(nestlevel);
1599 }
1600 
1601 /*
1602  * Append WHERE clause, containing conditions from exprs and additional_conds,
1603  * to context->buf.
1604  */
1605 static void
1606 appendWhereClause(List *exprs, List *additional_conds, deparse_expr_cxt *context)
1607 {
1608  StringInfo buf = context->buf;
1609  bool need_and = false;
1610  ListCell *lc;
1611 
1612  if (exprs != NIL || additional_conds != NIL)
1613  appendStringInfoString(buf, " WHERE ");
1614 
1615  /*
1616  * If there are some filters, append them.
1617  */
1618  if (exprs != NIL)
1619  {
1620  appendConditions(exprs, context);
1621  need_and = true;
1622  }
1623 
1624  /*
1625  * If there are some EXISTS conditions, coming from SEMI-JOINS, append
1626  * them.
1627  */
1628  foreach(lc, additional_conds)
1629  {
1630  if (need_and)
1631  appendStringInfoString(buf, " AND ");
1632  appendStringInfoString(buf, (char *) lfirst(lc));
1633  need_and = true;
1634  }
1635 }
1636 
1637 /* Output join name for given join type */
1638 const char *
1639 get_jointype_name(JoinType jointype)
1640 {
1641  switch (jointype)
1642  {
1643  case JOIN_INNER:
1644  return "INNER";
1645 
1646  case JOIN_LEFT:
1647  return "LEFT";
1648 
1649  case JOIN_RIGHT:
1650  return "RIGHT";
1651 
1652  case JOIN_FULL:
1653  return "FULL";
1654 
1655  case JOIN_SEMI:
1656  return "SEMI";
1657 
1658  default:
1659  /* Shouldn't come here, but protect from buggy code. */
1660  elog(ERROR, "unsupported join type %d", jointype);
1661  }
1662 
1663  /* Keep compiler happy */
1664  return NULL;
1665 }
1666 
1667 /*
1668  * Deparse given targetlist and append it to context->buf.
1669  *
1670  * tlist is list of TargetEntry's which in turn contain Var nodes.
1671  *
1672  * retrieved_attrs is the list of continuously increasing integers starting
1673  * from 1. It has same number of entries as tlist.
1674  *
1675  * This is used for both SELECT and RETURNING targetlists; the is_returning
1676  * parameter is true only for a RETURNING targetlist.
1677  */
1678 static void
1679 deparseExplicitTargetList(List *tlist,
1680  bool is_returning,
1681  List **retrieved_attrs,
1682  deparse_expr_cxt *context)
1683 {
1684  ListCell *lc;
1685  StringInfo buf = context->buf;
1686  int i = 0;
1687 
1688  *retrieved_attrs = NIL;
1689 
1690  foreach(lc, tlist)
1691  {
1692  TargetEntry *tle = lfirst_node(TargetEntry, lc);
1693 
1694  if (i > 0)
1695  appendStringInfoString(buf, ", ");
1696  else if (is_returning)
1697  appendStringInfoString(buf, " RETURNING ");
1698 
1699  deparseExpr((Expr *) tle->expr, context);
1700 
1701  *retrieved_attrs = lappend_int(*retrieved_attrs, i + 1);
1702  i++;
1703  }
1704 
1705  if (i == 0 && !is_returning)
1706  appendStringInfoString(buf, "NULL");
1707 }
1708 
1709 /*
1710  * Emit expressions specified in the given relation's reltarget.
1711  *
1712  * This is used for deparsing the given relation as a subquery.
1713  */
1714 static void
1715 deparseSubqueryTargetList(deparse_expr_cxt *context)
1716 {
1717  StringInfo buf = context->buf;
1718  RelOptInfo *foreignrel = context->foreignrel;
1719  bool first;
1720  ListCell *lc;
1721 
1722  /* Should only be called in these cases. */
1723  Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
1724 
1725  first = true;
1726  foreach(lc, foreignrel->reltarget->exprs)
1727  {
1728  Node *node = (Node *) lfirst(lc);
1729 
1730  if (!first)
1731  appendStringInfoString(buf, ", ");
1732  first = false;
1733 
1734  deparseExpr((Expr *) node, context);
1735  }
1736 
1737  /* Don't generate bad syntax if no expressions */
1738  if (first)
1739  appendStringInfoString(buf, "NULL");
1740 }
1741 
1742 /*
1743  * Construct FROM clause for given relation
1744  *
1745  * The function constructs ... JOIN ... ON ... for join relation. For a base
1746  * relation it just returns schema-qualified tablename, with the appropriate
1747  * alias if so requested.
1748  *
1749  * 'ignore_rel' is either zero or the RT index of a target relation. In the
1750  * latter case the function constructs FROM clause of UPDATE or USING clause
1751  * of DELETE; it deparses the join relation as if the relation never contained
1752  * the target relation, and creates a List of conditions to be deparsed into
1753  * the top-level WHERE clause, which is returned to *ignore_conds.
1754  *
1755  * 'additional_conds' is a pointer to a list of strings to be appended to
1756  * the WHERE clause, coming from lower-level SEMI-JOINs.
1757  */
1758 static void
1759 deparseFromExprForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
1760  bool use_alias, Index ignore_rel, List **ignore_conds,
1761  List **additional_conds, List **params_list)
1762 {
1763  PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1764 
1765  if (IS_JOIN_REL(foreignrel))
1766  {
1767  StringInfoData join_sql_o;
1768  StringInfoData join_sql_i;
1769  RelOptInfo *outerrel = fpinfo->outerrel;
1770  RelOptInfo *innerrel = fpinfo->innerrel;
1771  bool outerrel_is_target = false;
1772  bool innerrel_is_target = false;
1773  List *additional_conds_i = NIL;
1774  List *additional_conds_o = NIL;
1775 
1776  if (ignore_rel > 0 && bms_is_member(ignore_rel, foreignrel->relids))
1777  {
1778  /*
1779  * If this is an inner join, add joinclauses to *ignore_conds and
1780  * set it to empty so that those can be deparsed into the WHERE
1781  * clause. Note that since the target relation can never be
1782  * within the nullable side of an outer join, those could safely
1783  * be pulled up into the WHERE clause (see foreign_join_ok()).
1784  * Note also that since the target relation is only inner-joined
1785  * to any other relation in the query, all conditions in the join
1786  * tree mentioning the target relation could be deparsed into the
1787  * WHERE clause by doing this recursively.
1788  */
1789  if (fpinfo->jointype == JOIN_INNER)
1790  {
1791  *ignore_conds = list_concat(*ignore_conds,
1792  fpinfo->joinclauses);
1793  fpinfo->joinclauses = NIL;
1794  }
1795 
1796  /*
1797  * Check if either of the input relations is the target relation.
1798  */
1799  if (outerrel->relid == ignore_rel)
1800  outerrel_is_target = true;
1801  else if (innerrel->relid == ignore_rel)
1802  innerrel_is_target = true;
1803  }
1804 
1805  /* Deparse outer relation if not the target relation. */
1806  if (!outerrel_is_target)
1807  {
1808  initStringInfo(&join_sql_o);
1809  deparseRangeTblRef(&join_sql_o, root, outerrel,
1810  fpinfo->make_outerrel_subquery,
1811  ignore_rel, ignore_conds, &additional_conds_o,
1812  params_list);
1813 
1814  /*
1815  * If inner relation is the target relation, skip deparsing it.
1816  * Note that since the join of the target relation with any other
1817  * relation in the query is an inner join and can never be within
1818  * the nullable side of an outer join, the join could be
1819  * interchanged with higher-level joins (cf. identity 1 on outer
1820  * join reordering shown in src/backend/optimizer/README), which
1821  * means it's safe to skip the target-relation deparsing here.
1822  */
1823  if (innerrel_is_target)
1824  {
1825  Assert(fpinfo->jointype == JOIN_INNER);
1826  Assert(fpinfo->joinclauses == NIL);
1827  appendBinaryStringInfo(buf, join_sql_o.data, join_sql_o.len);
1828  /* Pass EXISTS conditions to upper level */
1829  if (additional_conds_o != NIL)
1830  {
1831  Assert(*additional_conds == NIL);
1832  *additional_conds = additional_conds_o;
1833  }
1834  return;
1835  }
1836  }
1837 
1838  /* Deparse inner relation if not the target relation. */
1839  if (!innerrel_is_target)
1840  {
1841  initStringInfo(&join_sql_i);
1842  deparseRangeTblRef(&join_sql_i, root, innerrel,
1843  fpinfo->make_innerrel_subquery,
1844  ignore_rel, ignore_conds, &additional_conds_i,
1845  params_list);
1846 
1847  /*
1848  * SEMI-JOIN is deparsed as the EXISTS subquery. It references
1849  * outer and inner relations, so it should be evaluated as the
1850  * condition in the upper-level WHERE clause. We deparse the
1851  * condition and pass it to upper level callers as an
1852  * additional_conds list. Upper level callers are responsible for
1853  * inserting conditions from the list where appropriate.
1854  */
1855  if (fpinfo->jointype == JOIN_SEMI)
1856  {
1857  deparse_expr_cxt context;
1858  StringInfoData str;
1859 
1860  /* Construct deparsed condition from this SEMI-JOIN */
1861  initStringInfo(&str);
1862  appendStringInfo(&str, "EXISTS (SELECT NULL FROM %s",
1863  join_sql_i.data);
1864 
1865  context.buf = &str;
1866  context.foreignrel = foreignrel;
1867  context.scanrel = foreignrel;
1868  context.root = root;
1869  context.params_list = params_list;
1870 
1871  /*
1872  * Append SEMI-JOIN clauses and EXISTS conditions from lower
1873  * levels to the current EXISTS subquery
1874  */
1875  appendWhereClause(fpinfo->joinclauses, additional_conds_i, &context);
1876 
1877  /*
1878  * EXISTS conditions, coming from lower join levels, have just
1879  * been processed.
1880  */
1881  if (additional_conds_i != NIL)
1882  {
1883  list_free_deep(additional_conds_i);
1884  additional_conds_i = NIL;
1885  }
1886 
1887  /* Close parentheses for EXISTS subquery */
1888  appendStringInfoChar(&str, ')');
1889 
1890  *additional_conds = lappend(*additional_conds, str.data);
1891  }
1892 
1893  /*
1894  * If outer relation is the target relation, skip deparsing it.
1895  * See the above note about safety.
1896  */
1897  if (outerrel_is_target)
1898  {
1899  Assert(fpinfo->jointype == JOIN_INNER);
1900  Assert(fpinfo->joinclauses == NIL);
1901  appendBinaryStringInfo(buf, join_sql_i.data, join_sql_i.len);
1902  /* Pass EXISTS conditions to the upper call */
1903  if (additional_conds_i != NIL)
1904  {
1905  Assert(*additional_conds == NIL);
1906  *additional_conds = additional_conds_i;
1907  }
1908  return;
1909  }
1910  }
1911 
1912  /* Neither of the relations is the target relation. */
1913  Assert(!outerrel_is_target && !innerrel_is_target);
1914 
1915  /*
1916  * For semijoin FROM clause is deparsed as an outer relation. An inner
1917  * relation and join clauses are converted to EXISTS condition and
1918  * passed to the upper level.
1919  */
1920  if (fpinfo->jointype == JOIN_SEMI)
1921  {
1922  appendBinaryStringInfo(buf, join_sql_o.data, join_sql_o.len);
1923  }
1924  else
1925  {
1926  /*
1927  * For a join relation FROM clause, entry is deparsed as
1928  *
1929  * ((outer relation) <join type> (inner relation) ON
1930  * (joinclauses))
1931  */
1932  appendStringInfo(buf, "(%s %s JOIN %s ON ", join_sql_o.data,
1933  get_jointype_name(fpinfo->jointype), join_sql_i.data);
1934 
1935  /* Append join clause; (TRUE) if no join clause */
1936  if (fpinfo->joinclauses)
1937  {
1938  deparse_expr_cxt context;
1939 
1940  context.buf = buf;
1941  context.foreignrel = foreignrel;
1942  context.scanrel = foreignrel;
1943  context.root = root;
1944  context.params_list = params_list;
1945 
1946  appendStringInfoChar(buf, '(');
1947  appendConditions(fpinfo->joinclauses, &context);
1948  appendStringInfoChar(buf, ')');
1949  }
1950  else
1951  appendStringInfoString(buf, "(TRUE)");
1952 
1953  /* End the FROM clause entry. */
1954  appendStringInfoChar(buf, ')');
1955  }
1956 
1957  /*
1958  * Construct additional_conds to be passed to the upper caller from
1959  * current level additional_conds and additional_conds, coming from
1960  * inner and outer rels.
1961  */
1962  if (additional_conds_o != NIL)
1963  {
1964  *additional_conds = list_concat(*additional_conds,
1965  additional_conds_o);
1966  list_free(additional_conds_o);
1967  }
1968 
1969  if (additional_conds_i != NIL)
1970  {
1971  *additional_conds = list_concat(*additional_conds,
1972  additional_conds_i);
1973  list_free(additional_conds_i);
1974  }
1975  }
1976  else
1977  {
1978  RangeTblEntry *rte = planner_rt_fetch(foreignrel->relid, root);
1979 
1980  /*
1981  * Core code already has some lock on each rel being planned, so we
1982  * can use NoLock here.
1983  */
1984  Relation rel = table_open(rte->relid, NoLock);
1985 
1986  deparseRelation(buf, rel);
1987 
1988  /*
1989  * Add a unique alias to avoid any conflict in relation names due to
1990  * pulled up subqueries in the query being built for a pushed down
1991  * join.
1992  */
1993  if (use_alias)
1994  appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, foreignrel->relid);
1995 
1996  table_close(rel, NoLock);
1997  }
1998 }
1999 
2000 /*
2001  * Append FROM clause entry for the given relation into buf.
2002  * Conditions from lower-level SEMI-JOINs are appended to additional_conds
2003  * and should be added to upper level WHERE clause.
2004  */
2005 static void
2006 deparseRangeTblRef(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
2007  bool make_subquery, Index ignore_rel, List **ignore_conds,
2008  List **additional_conds, List **params_list)
2009 {
2010  PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
2011 
2012  /* Should only be called in these cases. */
2013  Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
2014 
2015  Assert(fpinfo->local_conds == NIL);
2016 
2017  /* If make_subquery is true, deparse the relation as a subquery. */
2018  if (make_subquery)
2019  {
2020  List *retrieved_attrs;
2021  int ncols;
2022 
2023  /*
2024  * The given relation shouldn't contain the target relation, because
2025  * this should only happen for input relations for a full join, and
2026  * such relations can never contain an UPDATE/DELETE target.
2027  */
2028  Assert(ignore_rel == 0 ||
2029  !bms_is_member(ignore_rel, foreignrel->relids));
2030 
2031  /* Deparse the subquery representing the relation. */
2032  appendStringInfoChar(buf, '(');
2033  deparseSelectStmtForRel(buf, root, foreignrel, NIL,
2034  fpinfo->remote_conds, NIL,
2035  false, false, true,
2036  &retrieved_attrs, params_list);
2037  appendStringInfoChar(buf, ')');
2038 
2039  /* Append the relation alias. */
2040  appendStringInfo(buf, " %s%d", SUBQUERY_REL_ALIAS_PREFIX,
2041  fpinfo->relation_index);
2042 
2043  /*
2044  * Append the column aliases if needed. Note that the subquery emits
2045  * expressions specified in the relation's reltarget (see
2046  * deparseSubqueryTargetList).
2047  */
2048  ncols = list_length(foreignrel->reltarget->exprs);
2049  if (ncols > 0)
2050  {
2051  int i;
2052 
2053  appendStringInfoChar(buf, '(');
2054  for (i = 1; i <= ncols; i++)
2055  {
2056  if (i > 1)
2057  appendStringInfoString(buf, ", ");
2058 
2059  appendStringInfo(buf, "%s%d", SUBQUERY_COL_ALIAS_PREFIX, i);
2060  }
2061  appendStringInfoChar(buf, ')');
2062  }
2063  }
2064  else
2065  deparseFromExprForRel(buf, root, foreignrel, true, ignore_rel,
2066  ignore_conds, additional_conds,
2067  params_list);
2068 }
2069 
2070 /*
2071  * deparse remote INSERT statement
2072  *
2073  * The statement text is appended to buf, and we also create an integer List
2074  * of the columns being retrieved by WITH CHECK OPTION or RETURNING (if any),
2075  * which is returned to *retrieved_attrs.
2076  *
2077  * This also stores end position of the VALUES clause, so that we can rebuild
2078  * an INSERT for a batch of rows later.
2079  */
2080 void
2081 deparseInsertSql(StringInfo buf, RangeTblEntry *rte,
2082  Index rtindex, Relation rel,
2083  List *targetAttrs, bool doNothing,
2084  List *withCheckOptionList, List *returningList,
2085  List **retrieved_attrs, int *values_end_len)
2086 {
2087  TupleDesc tupdesc = RelationGetDescr(rel);
2088  AttrNumber pindex;
2089  bool first;
2090  ListCell *lc;
2091 
2092  appendStringInfoString(buf, "INSERT INTO ");
2093  deparseRelation(buf, rel);
2094 
2095  if (targetAttrs)
2096  {
2097  appendStringInfoChar(buf, '(');
2098 
2099  first = true;
2100  foreach(lc, targetAttrs)
2101  {
2102  int attnum = lfirst_int(lc);
2103 
2104  if (!first)
2105  appendStringInfoString(buf, ", ");
2106  first = false;
2107 
2108  deparseColumnRef(buf, rtindex, attnum, rte, false);
2109  }
2110 
2111  appendStringInfoString(buf, ") VALUES (");
2112 
2113  pindex = 1;
2114  first = true;
2115  foreach(lc, targetAttrs)
2116  {
2117  int attnum = lfirst_int(lc);
2118  Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
2119 
2120  if (!first)
2121  appendStringInfoString(buf, ", ");
2122  first = false;
2123 
2124  if (attr->attgenerated)
2125  appendStringInfoString(buf, "DEFAULT");
2126  else
2127  {
2128  appendStringInfo(buf, "$%d", pindex);
2129  pindex++;
2130  }
2131  }
2132 
2133  appendStringInfoChar(buf, ')');
2134  }
2135  else
2136  appendStringInfoString(buf, " DEFAULT VALUES");
2137  *values_end_len = buf->len;
2138 
2139  if (doNothing)
2140  appendStringInfoString(buf, " ON CONFLICT DO NOTHING");
2141 
2142  deparseReturningList(buf, rte, rtindex, rel,
2143  rel->trigdesc && rel->trigdesc->trig_insert_after_row,
2144  withCheckOptionList, returningList, retrieved_attrs);
2145 }
2146 
2147 /*
2148  * rebuild remote INSERT statement
2149  *
2150  * Provided a number of rows in a batch, builds INSERT statement with the
2151  * right number of parameters.
2152  */
2153 void
2154 rebuildInsertSql(StringInfo buf, Relation rel,
2155  char *orig_query, List *target_attrs,
2156  int values_end_len, int num_params,
2157  int num_rows)
2158 {
2159  TupleDesc tupdesc = RelationGetDescr(rel);
2160  int i;
2161  int pindex;
2162  bool first;
2163  ListCell *lc;
2164 
2165  /* Make sure the values_end_len is sensible */
2166  Assert((values_end_len > 0) && (values_end_len <= strlen(orig_query)));
2167 
2168  /* Copy up to the end of the first record from the original query */
2169  appendBinaryStringInfo(buf, orig_query, values_end_len);
2170 
2171  /*
2172  * Add records to VALUES clause (we already have parameters for the first
2173  * row, so start at the right offset).
2174  */
2175  pindex = num_params + 1;
2176  for (i = 0; i < num_rows; i++)
2177  {
2178  appendStringInfoString(buf, ", (");
2179 
2180  first = true;
2181  foreach(lc, target_attrs)
2182  {
2183  int attnum = lfirst_int(lc);
2184  Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
2185 
2186  if (!first)
2187  appendStringInfoString(buf, ", ");
2188  first = false;
2189 
2190  if (attr->attgenerated)
2191  appendStringInfoString(buf, "DEFAULT");
2192  else
2193  {
2194  appendStringInfo(buf, "$%d", pindex);
2195  pindex++;
2196  }
2197  }
2198 
2199  appendStringInfoChar(buf, ')');
2200  }
2201 
2202  /* Copy stuff after VALUES clause from the original query */
2203  appendStringInfoString(buf, orig_query + values_end_len);
2204 }
2205 
2206 /*
2207  * deparse remote UPDATE statement
2208  *
2209  * The statement text is appended to buf, and we also create an integer List
2210  * of the columns being retrieved by WITH CHECK OPTION or RETURNING (if any),
2211  * which is returned to *retrieved_attrs.
2212  */
2213 void
2214 deparseUpdateSql(StringInfo buf, RangeTblEntry *rte,
2215  Index rtindex, Relation rel,
2216  List *targetAttrs,
2217  List *withCheckOptionList, List *returningList,
2218  List **retrieved_attrs)
2219 {
2220  TupleDesc tupdesc = RelationGetDescr(rel);
2221  AttrNumber pindex;
2222  bool first;
2223  ListCell *lc;
2224 
2225  appendStringInfoString(buf, "UPDATE ");
2226  deparseRelation(buf, rel);
2227  appendStringInfoString(buf, " SET ");
2228 
2229  pindex = 2; /* ctid is always the first param */
2230  first = true;
2231  foreach(lc, targetAttrs)
2232  {
2233  int attnum = lfirst_int(lc);
2234  Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
2235 
2236  if (!first)
2237  appendStringInfoString(buf, ", ");
2238  first = false;
2239 
2240  deparseColumnRef(buf, rtindex, attnum, rte, false);
2241  if (attr->attgenerated)
2242  appendStringInfoString(buf, " = DEFAULT");
2243  else
2244  {
2245  appendStringInfo(buf, " = $%d", pindex);
2246  pindex++;
2247  }
2248  }
2249  appendStringInfoString(buf, " WHERE ctid = $1");
2250 
2251  deparseReturningList(buf, rte, rtindex, rel,
2252  rel->trigdesc && rel->trigdesc->trig_update_after_row,
2253  withCheckOptionList, returningList, retrieved_attrs);
2254 }
2255 
2256 /*
2257  * deparse remote UPDATE statement
2258  *
2259  * 'buf' is the output buffer to append the statement to
2260  * 'rtindex' is the RT index of the associated target relation
2261  * 'rel' is the relation descriptor for the target relation
2262  * 'foreignrel' is the RelOptInfo for the target relation or the join relation
2263  * containing all base relations in the query
2264  * 'targetlist' is the tlist of the underlying foreign-scan plan node
2265  * (note that this only contains new-value expressions and junk attrs)
2266  * 'targetAttrs' is the target columns of the UPDATE
2267  * 'remote_conds' is the qual clauses that must be evaluated remotely
2268  * '*params_list' is an output list of exprs that will become remote Params
2269  * 'returningList' is the RETURNING targetlist
2270  * '*retrieved_attrs' is an output list of integers of columns being retrieved
2271  * by RETURNING (if any)
2272  */
2273 void
2274 deparseDirectUpdateSql(StringInfo buf, PlannerInfo *root,
2275  Index rtindex, Relation rel,
2276  RelOptInfo *foreignrel,
2277  List *targetlist,
2278  List *targetAttrs,
2279  List *remote_conds,
2280  List **params_list,
2281  List *returningList,
2282  List **retrieved_attrs)
2283 {
2284  deparse_expr_cxt context;
2285  int nestlevel;
2286  bool first;
2287  RangeTblEntry *rte = planner_rt_fetch(rtindex, root);
2288  ListCell *lc,
2289  *lc2;
2290  List *additional_conds = NIL;
2291 
2292  /* Set up context struct for recursion */
2293  context.root = root;
2294  context.foreignrel = foreignrel;
2295  context.scanrel = foreignrel;
2296  context.buf = buf;
2297  context.params_list = params_list;
2298 
2299  appendStringInfoString(buf, "UPDATE ");
2300  deparseRelation(buf, rel);
2301  if (foreignrel->reloptkind == RELOPT_JOINREL)
2302  appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, rtindex);
2303  appendStringInfoString(buf, " SET ");
2304 
2305  /* Make sure any constants in the exprs are printed portably */
2306  nestlevel = set_transmission_modes();
2307 
2308  first = true;
2309  forboth(lc, targetlist, lc2, targetAttrs)
2310  {
2311  TargetEntry *tle = lfirst_node(TargetEntry, lc);
2312  int attnum = lfirst_int(lc2);
2313 
2314  /* update's new-value expressions shouldn't be resjunk */
2315  Assert(!tle->resjunk);
2316 
2317  if (!first)
2318  appendStringInfoString(buf, ", ");
2319  first = false;
2320 
2321  deparseColumnRef(buf, rtindex, attnum, rte, false);
2322  appendStringInfoString(buf, " = ");
2323  deparseExpr((Expr *) tle->expr, &context);
2324  }
2325 
2326  reset_transmission_modes(nestlevel);
2327 
2328  if (foreignrel->reloptkind == RELOPT_JOINREL)
2329  {
2330  List *ignore_conds = NIL;
2331 
2332 
2333  appendStringInfoString(buf, " FROM ");
2334  deparseFromExprForRel(buf, root, foreignrel, true, rtindex,
2335  &ignore_conds, &additional_conds, params_list);
2336  remote_conds = list_concat(remote_conds, ignore_conds);
2337  }
2338 
2339  appendWhereClause(remote_conds, additional_conds, &context);
2340 
2341  if (additional_conds != NIL)
2342  list_free_deep(additional_conds);
2343 
2344  if (foreignrel->reloptkind == RELOPT_JOINREL)
2345  deparseExplicitTargetList(returningList, true, retrieved_attrs,
2346  &context);
2347  else
2348  deparseReturningList(buf, rte, rtindex, rel, false,
2349  NIL, returningList, retrieved_attrs);
2350 }
2351 
2352 /*
2353  * deparse remote DELETE statement
2354  *
2355  * The statement text is appended to buf, and we also create an integer List
2356  * of the columns being retrieved by RETURNING (if any), which is returned
2357  * to *retrieved_attrs.
2358  */
2359 void
2360 deparseDeleteSql(StringInfo buf, RangeTblEntry *rte,
2361  Index rtindex, Relation rel,
2362  List *returningList,
2363  List **retrieved_attrs)
2364 {
2365  appendStringInfoString(buf, "DELETE FROM ");
2366  deparseRelation(buf, rel);
2367  appendStringInfoString(buf, " WHERE ctid = $1");
2368 
2369  deparseReturningList(buf, rte, rtindex, rel,
2370  rel->trigdesc && rel->trigdesc->trig_delete_after_row,
2371  NIL, returningList, retrieved_attrs);
2372 }
2373 
2374 /*
2375  * deparse remote DELETE statement
2376  *
2377  * 'buf' is the output buffer to append the statement to
2378  * 'rtindex' is the RT index of the associated target relation
2379  * 'rel' is the relation descriptor for the target relation
2380  * 'foreignrel' is the RelOptInfo for the target relation or the join relation
2381  * containing all base relations in the query
2382  * 'remote_conds' is the qual clauses that must be evaluated remotely
2383  * '*params_list' is an output list of exprs that will become remote Params
2384  * 'returningList' is the RETURNING targetlist
2385  * '*retrieved_attrs' is an output list of integers of columns being retrieved
2386  * by RETURNING (if any)
2387  */
2388 void
2389 deparseDirectDeleteSql(StringInfo buf, PlannerInfo *root,
2390  Index rtindex, Relation rel,
2391  RelOptInfo *foreignrel,
2392  List *remote_conds,
2393  List **params_list,
2394  List *returningList,
2395  List **retrieved_attrs)
2396 {
2397  deparse_expr_cxt context;
2398  List *additional_conds = NIL;
2399 
2400  /* Set up context struct for recursion */
2401  context.root = root;
2402  context.foreignrel = foreignrel;
2403  context.scanrel = foreignrel;
2404  context.buf = buf;
2405  context.params_list = params_list;
2406 
2407  appendStringInfoString(buf, "DELETE FROM ");
2408  deparseRelation(buf, rel);
2409  if (foreignrel->reloptkind == RELOPT_JOINREL)
2410  appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, rtindex);
2411 
2412  if (foreignrel->reloptkind == RELOPT_JOINREL)
2413  {
2414  List *ignore_conds = NIL;
2415 
2416  appendStringInfoString(buf, " USING ");
2417  deparseFromExprForRel(buf, root, foreignrel, true, rtindex,
2418  &ignore_conds, &additional_conds, params_list);
2419  remote_conds = list_concat(remote_conds, ignore_conds);
2420  }
2421 
2422  appendWhereClause(remote_conds, additional_conds, &context);
2423 
2424  if (additional_conds != NIL)
2425  list_free_deep(additional_conds);
2426 
2427  if (foreignrel->reloptkind == RELOPT_JOINREL)
2428  deparseExplicitTargetList(returningList, true, retrieved_attrs,
2429  &context);
2430  else
2431  deparseReturningList(buf, planner_rt_fetch(rtindex, root),
2432  rtindex, rel, false,
2433  NIL, returningList, retrieved_attrs);
2434 }
2435 
2436 /*
2437  * Add a RETURNING clause, if needed, to an INSERT/UPDATE/DELETE.
2438  */
2439 static void
2440 deparseReturningList(StringInfo buf, RangeTblEntry *rte,
2441  Index rtindex, Relation rel,
2442  bool trig_after_row,
2443  List *withCheckOptionList,
2444  List *returningList,
2445  List **retrieved_attrs)
2446 {
2447  Bitmapset *attrs_used = NULL;
2448 
2449  if (trig_after_row)
2450  {
2451  /* whole-row reference acquires all non-system columns */
2452  attrs_used =
2453  bms_make_singleton(0 - FirstLowInvalidHeapAttributeNumber);
2454  }
2455 
2456  if (withCheckOptionList != NIL)
2457  {
2458  /*
2459  * We need the attrs, non-system and system, mentioned in the local
2460  * query's WITH CHECK OPTION list.
2461  *
2462  * Note: we do this to ensure that WCO constraints will be evaluated
2463  * on the data actually inserted/updated on the remote side, which
2464  * might differ from the data supplied by the core code, for example
2465  * as a result of remote triggers.
2466  */
2467  pull_varattnos((Node *) withCheckOptionList, rtindex,
2468  &attrs_used);
2469  }
2470 
2471  if (returningList != NIL)
2472  {
2473  /*
2474  * We need the attrs, non-system and system, mentioned in the local
2475  * query's RETURNING list.
2476  */
2477  pull_varattnos((Node *) returningList, rtindex,
2478  &attrs_used);
2479  }
2480 
2481  if (attrs_used != NULL)
2482  deparseTargetList(buf, rte, rtindex, rel, true, attrs_used, false,
2483  retrieved_attrs);
2484  else
2485  *retrieved_attrs = NIL;
2486 }
2487 
2488 /*
2489  * Construct SELECT statement to acquire size in blocks of given relation.
2490  *
2491  * Note: we use local definition of block size, not remote definition.
2492  * This is perhaps debatable.
2493  *
2494  * Note: pg_relation_size() exists in 8.1 and later.
2495  */
2496 void
2497 deparseAnalyzeSizeSql(StringInfo buf, Relation rel)
2498 {
2499  StringInfoData relname;
2500 
2501  /* We'll need the remote relation name as a literal. */
2502  initStringInfo(&relname);
2503  deparseRelation(&relname, rel);
2504 
2505  appendStringInfoString(buf, "SELECT pg_catalog.pg_relation_size(");
2506  deparseStringLiteral(buf, relname.data);
2507  appendStringInfo(buf, "::pg_catalog.regclass) / %d", BLCKSZ);
2508 }
2509 
2510 /*
2511  * Construct SELECT statement to acquire the number of rows and the relkind of
2512  * a relation.
2513  *
2514  * Note: we just return the remote server's reltuples value, which might
2515  * be off a good deal, but it doesn't seem worth working harder. See
2516  * comments in postgresAcquireSampleRowsFunc.
2517  */
2518 void
2519 deparseAnalyzeInfoSql(StringInfo buf, Relation rel)
2520 {
2521  StringInfoData relname;
2522 
2523  /* We'll need the remote relation name as a literal. */
2524  initStringInfo(&relname);
2525  deparseRelation(&relname, rel);
2526 
2527  appendStringInfoString(buf, "SELECT reltuples, relkind FROM pg_catalog.pg_class WHERE oid = ");
2528  deparseStringLiteral(buf, relname.data);
2529  appendStringInfoString(buf, "::pg_catalog.regclass");
2530 }
2531 
2532 /*
2533  * Construct SELECT statement to acquire sample rows of given relation.
2534  *
2535  * SELECT command is appended to buf, and list of columns retrieved
2536  * is returned to *retrieved_attrs.
2537  *
2538  * We only support sampling methods we can decide based on server version.
2539  * Allowing custom TSM modules (like tsm_system_rows) might be useful, but it
2540  * would require detecting which extensions are installed, to allow automatic
2541  * fall-back. Moreover, the methods may use different parameters like number
2542  * of rows (and not sampling rate). So we leave this for future improvements.
2543  *
2544  * Using random() to sample rows on the remote server has the advantage that
2545  * this works on all PostgreSQL versions (unlike TABLESAMPLE), and that it
2546  * does the sampling on the remote side (without transferring everything and
2547  * then discarding most rows).
2548  *
2549  * The disadvantage is that we still have to read all rows and evaluate the
2550  * random(), while TABLESAMPLE (at least with the "system" method) may skip.
2551  * It's not that different from the "bernoulli" method, though.
2552  *
2553  * We could also do "ORDER BY random() LIMIT x", which would always pick
2554  * the expected number of rows, but it requires sorting so it may be much
2555  * more expensive (particularly on large tables, which is what the
2556  * remote sampling is meant to improve).
2557  */
2558 void
2559 deparseAnalyzeSql(StringInfo buf, Relation rel,
2560  PgFdwSamplingMethod sample_method, double sample_frac,
2561  List **retrieved_attrs)
2562 {
2563  Oid relid = RelationGetRelid(rel);
2564  TupleDesc tupdesc = RelationGetDescr(rel);
2565  int i;
2566  char *colname;
2567  List *options;
2568  ListCell *lc;
2569  bool first = true;
2570 
2571  *retrieved_attrs = NIL;
2572 
2573  appendStringInfoString(buf, "SELECT ");
2574  for (i = 0; i < tupdesc->natts; i++)
2575  {
2576  /* Ignore dropped columns. */
2577  if (TupleDescAttr(tupdesc, i)->attisdropped)
2578  continue;
2579 
2580  if (!first)
2581  appendStringInfoString(buf, ", ");
2582  first = false;
2583 
2584  /* Use attribute name or column_name option. */
2585  colname = NameStr(TupleDescAttr(tupdesc, i)->attname);
2586  options = GetForeignColumnOptions(relid, i + 1);
2587 
2588  foreach(lc, options)
2589  {
2590  DefElem *def = (DefElem *) lfirst(lc);
2591 
2592  if (strcmp(def->defname, "column_name") == 0)
2593  {
2594  colname = defGetString(def);
2595  break;
2596  }
2597  }
2598 
2599  appendStringInfoString(buf, quote_identifier(colname));
2600 
2601  *retrieved_attrs = lappend_int(*retrieved_attrs, i + 1);
2602  }
2603 
2604  /* Don't generate bad syntax for zero-column relation. */
2605  if (first)
2606  appendStringInfoString(buf, "NULL");
2607 
2608  /*
2609  * Construct FROM clause, and perhaps WHERE clause too, depending on the
2610  * selected sampling method.
2611  */
2612  appendStringInfoString(buf, " FROM ");
2613  deparseRelation(buf, rel);
2614 
2615  switch (sample_method)
2616  {
2617  case ANALYZE_SAMPLE_OFF:
2618  /* nothing to do here */
2619  break;
2620 
2621  case ANALYZE_SAMPLE_RANDOM:
2622  appendStringInfo(buf, " WHERE pg_catalog.random() < %f", sample_frac);
2623  break;
2624 
2625  case ANALYZE_SAMPLE_SYSTEM:
2626  appendStringInfo(buf, " TABLESAMPLE SYSTEM(%f)", (100.0 * sample_frac));
2627  break;
2628 
2629  case ANALYZE_SAMPLE_BERNOULLI:
2630  appendStringInfo(buf, " TABLESAMPLE BERNOULLI(%f)", (100.0 * sample_frac));
2631  break;
2632 
2633  case ANALYZE_SAMPLE_AUTO:
2634  /* should have been resolved into actual method */
2635  elog(ERROR, "unexpected sampling method");
2636  break;
2637  }
2638 }
2639 
2640 /*
2641  * Construct a simple "TRUNCATE rel" statement
2642  */
2643 void
2644 deparseTruncateSql(StringInfo buf,
2645  List *rels,
2646  DropBehavior behavior,
2647  bool restart_seqs)
2648 {
2649  ListCell *cell;
2650 
2651  appendStringInfoString(buf, "TRUNCATE ");
2652 
2653  foreach(cell, rels)
2654  {
2655  Relation rel = lfirst(cell);
2656 
2657  if (cell != list_head(rels))
2658  appendStringInfoString(buf, ", ");
2659 
2660  deparseRelation(buf, rel);
2661  }
2662 
2663  appendStringInfo(buf, " %s IDENTITY",
2664  restart_seqs ? "RESTART" : "CONTINUE");
2665 
2666  if (behavior == DROP_RESTRICT)
2667  appendStringInfoString(buf, " RESTRICT");
2668  else if (behavior == DROP_CASCADE)
2669  appendStringInfoString(buf, " CASCADE");
2670 }
2671 
2672 /*
2673  * Construct name to use for given column, and emit it into buf.
2674  * If it has a column_name FDW option, use that instead of attribute name.
2675  *
2676  * If qualify_col is true, qualify column name with the alias of relation.
2677  */
2678 static void
2679 deparseColumnRef(StringInfo buf, int varno, int varattno, RangeTblEntry *rte,
2680  bool qualify_col)
2681 {
2682  /* We support fetching the remote side's CTID and OID. */
2683  if (varattno == SelfItemPointerAttributeNumber)
2684  {
2685  if (qualify_col)
2686  ADD_REL_QUALIFIER(buf, varno);
2687  appendStringInfoString(buf, "ctid");
2688  }
2689  else if (varattno < 0)
2690  {
2691  /*
2692  * All other system attributes are fetched as 0, except for table OID,
2693  * which is fetched as the local table OID. However, we must be
2694  * careful; the table could be beneath an outer join, in which case it
2695  * must go to NULL whenever the rest of the row does.
2696  */
2697  Oid fetchval = 0;
2698 
2699  if (varattno == TableOidAttributeNumber)
2700  fetchval = rte->relid;
2701 
2702  if (qualify_col)
2703  {
2704  appendStringInfoString(buf, "CASE WHEN (");
2705  ADD_REL_QUALIFIER(buf, varno);
2706  appendStringInfo(buf, "*)::text IS NOT NULL THEN %u END", fetchval);
2707  }
2708  else
2709  appendStringInfo(buf, "%u", fetchval);
2710  }
2711  else if (varattno == 0)
2712  {
2713  /* Whole row reference */
2714  Relation rel;
2715  Bitmapset *attrs_used;
2716 
2717  /* Required only to be passed down to deparseTargetList(). */
2718  List *retrieved_attrs;
2719 
2720  /*
2721  * The lock on the relation will be held by upper callers, so it's
2722  * fine to open it with no lock here.
2723  */
2724  rel = table_open(rte->relid, NoLock);
2725 
2726  /*
2727  * The local name of the foreign table can not be recognized by the
2728  * foreign server and the table it references on foreign server might
2729  * have different column ordering or different columns than those
2730  * declared locally. Hence we have to deparse whole-row reference as
2731  * ROW(columns referenced locally). Construct this by deparsing a
2732  * "whole row" attribute.
2733  */
2734  attrs_used = bms_add_member(NULL,
2735  0 - FirstLowInvalidHeapAttributeNumber);
2736 
2737  /*
2738  * In case the whole-row reference is under an outer join then it has
2739  * to go NULL whenever the rest of the row goes NULL. Deparsing a join
2740  * query would always involve multiple relations, thus qualify_col
2741  * would be true.
2742  */
2743  if (qualify_col)
2744  {
2745  appendStringInfoString(buf, "CASE WHEN (");
2746  ADD_REL_QUALIFIER(buf, varno);
2747  appendStringInfoString(buf, "*)::text IS NOT NULL THEN ");
2748  }
2749 
2750  appendStringInfoString(buf, "ROW(");
2751  deparseTargetList(buf, rte, varno, rel, false, attrs_used, qualify_col,
2752  &retrieved_attrs);
2753  appendStringInfoChar(buf, ')');
2754 
2755  /* Complete the CASE WHEN statement started above. */
2756  if (qualify_col)
2757  appendStringInfoString(buf, " END");
2758 
2759  table_close(rel, NoLock);
2760  bms_free(attrs_used);
2761  }
2762  else
2763  {
2764  char *colname = NULL;
2765  List *options;
2766  ListCell *lc;
2767 
2768  /* varno must not be any of OUTER_VAR, INNER_VAR and INDEX_VAR. */
2769  Assert(!IS_SPECIAL_VARNO(varno));
2770 
2771  /*
2772  * If it's a column of a foreign table, and it has the column_name FDW
2773  * option, use that value.
2774  */
2775  options = GetForeignColumnOptions(rte->relid, varattno);
2776  foreach(lc, options)
2777  {
2778  DefElem *def = (DefElem *) lfirst(lc);
2779 
2780  if (strcmp(def->defname, "column_name") == 0)
2781  {
2782  colname = defGetString(def);
2783  break;
2784  }
2785  }
2786 
2787  /*
2788  * If it's a column of a regular table or it doesn't have column_name
2789  * FDW option, use attribute name.
2790  */
2791  if (colname == NULL)
2792  colname = get_attname(rte->relid, varattno, false);
2793 
2794  if (qualify_col)
2795  ADD_REL_QUALIFIER(buf, varno);
2796 
2797  appendStringInfoString(buf, quote_identifier(colname));
2798  }
2799 }
2800 
2801 /*
2802  * Append remote name of specified foreign table to buf.
2803  * Use value of table_name FDW option (if any) instead of relation's name.
2804  * Similarly, schema_name FDW option overrides schema name.
2805  */
2806 static void
2807 deparseRelation(StringInfo buf, Relation rel)
2808 {
2809  ForeignTable *table;
2810  const char *nspname = NULL;
2811  const char *relname = NULL;
2812  ListCell *lc;
2813 
2814  /* obtain additional catalog information. */
2815  table = GetForeignTable(RelationGetRelid(rel));
2816 
2817  /*
2818  * Use value of FDW options if any, instead of the name of object itself.
2819  */
2820  foreach(lc, table->options)
2821  {
2822  DefElem *def = (DefElem *) lfirst(lc);
2823 
2824  if (strcmp(def->defname, "schema_name") == 0)
2825  nspname = defGetString(def);
2826  else if (strcmp(def->defname, "table_name") == 0)
2827  relname = defGetString(def);
2828  }
2829 
2830  /*
2831  * Note: we could skip printing the schema name if it's pg_catalog, but
2832  * that doesn't seem worth the trouble.
2833  */
2834  if (nspname == NULL)
2835  nspname = get_namespace_name(RelationGetNamespace(rel));
2836  if (relname == NULL)
2837  relname = RelationGetRelationName(rel);
2838 
2839  appendStringInfo(buf, "%s.%s",
2840  quote_identifier(nspname), quote_identifier(relname));
2841 }
2842 
2843 /*
2844  * Append a SQL string literal representing "val" to buf.
2845  */
2846 void
2847 deparseStringLiteral(StringInfo buf, const char *val)
2848 {
2849  const char *valptr;
2850 
2851  /*
2852  * Rather than making assumptions about the remote server's value of
2853  * standard_conforming_strings, always use E'foo' syntax if there are any
2854  * backslashes. This will fail on remote servers before 8.1, but those
2855  * are long out of support.
2856  */
2857  if (strchr(val, '\\') != NULL)
2858  appendStringInfoChar(buf, ESCAPE_STRING_SYNTAX);
2859  appendStringInfoChar(buf, '\'');
2860  for (valptr = val; *valptr; valptr++)
2861  {
2862  char ch = *valptr;
2863 
2864  if (SQL_STR_DOUBLE(ch, true))
2865  appendStringInfoChar(buf, ch);
2866  appendStringInfoChar(buf, ch);
2867  }
2868  appendStringInfoChar(buf, '\'');
2869 }
2870 
2871 /*
2872  * Deparse given expression into context->buf.
2873  *
2874  * This function must support all the same node types that foreign_expr_walker
2875  * accepts.
2876  *
2877  * Note: unlike ruleutils.c, we just use a simple hard-wired parenthesization
2878  * scheme: anything more complex than a Var, Const, function call or cast
2879  * should be self-parenthesized.
2880  */
2881 static void
2882 deparseExpr(Expr *node, deparse_expr_cxt *context)
2883 {
2884  if (node == NULL)
2885  return;
2886 
2887  switch (nodeTag(node))
2888  {
2889  case T_Var:
2890  deparseVar((Var *) node, context);
2891  break;
2892  case T_Const:
2893  deparseConst((Const *) node, context, 0);
2894  break;
2895  case T_Param:
2896  deparseParam((Param *) node, context);
2897  break;
2898  case T_SubscriptingRef:
2899  deparseSubscriptingRef((SubscriptingRef *) node, context);
2900  break;
2901  case T_FuncExpr:
2902  deparseFuncExpr((FuncExpr *) node, context);
2903  break;
2904  case T_OpExpr:
2905  deparseOpExpr((OpExpr *) node, context);
2906  break;
2907  case T_DistinctExpr:
2908  deparseDistinctExpr((DistinctExpr *) node, context);
2909  break;
2910  case T_ScalarArrayOpExpr:
2911  deparseScalarArrayOpExpr((ScalarArrayOpExpr *) node, context);
2912  break;
2913  case T_RelabelType:
2914  deparseRelabelType((RelabelType *) node, context);
2915  break;
2916  case T_BoolExpr:
2917  deparseBoolExpr((BoolExpr *) node, context);
2918  break;
2919  case T_NullTest:
2920  deparseNullTest((NullTest *) node, context);
2921  break;
2922  case T_CaseExpr:
2923  deparseCaseExpr((CaseExpr *) node, context);
2924  break;
2925  case T_ArrayExpr:
2926  deparseArrayExpr((ArrayExpr *) node, context);
2927  break;
2928  case T_Aggref:
2929  deparseAggref((Aggref *) node, context);
2930  break;
2931  default:
2932  elog(ERROR, "unsupported expression type for deparse: %d",
2933  (int) nodeTag(node));
2934  break;
2935  }
2936 }
2937 
2938 /*
2939  * Deparse given Var node into context->buf.
2940  *
2941  * If the Var belongs to the foreign relation, just print its remote name.
2942  * Otherwise, it's effectively a Param (and will in fact be a Param at
2943  * run time). Handle it the same way we handle plain Params --- see
2944  * deparseParam for comments.
2945  */
2946 static void
2947 deparseVar(Var *node, deparse_expr_cxt *context)
2948 {
2949  Relids relids = context->scanrel->relids;
2950  int relno;
2951  int colno;
2952 
2953  /* Qualify columns when multiple relations are involved. */
2954  bool qualify_col = (bms_membership(relids) == BMS_MULTIPLE);
2955 
2956  /*
2957  * If the Var belongs to the foreign relation that is deparsed as a
2958  * subquery, use the relation and column alias to the Var provided by the
2959  * subquery, instead of the remote name.
2960  */
2961  if (is_subquery_var(node, context->scanrel, &relno, &colno))
2962  {
2963  appendStringInfo(context->buf, "%s%d.%s%d",
2964  SUBQUERY_REL_ALIAS_PREFIX, relno,
2965  SUBQUERY_COL_ALIAS_PREFIX, colno);
2966  return;
2967  }
2968 
2969  if (bms_is_member(node->varno, relids) && node->varlevelsup == 0)
2970  deparseColumnRef(context->buf, node->varno, node->varattno,
2971  planner_rt_fetch(node->varno, context->root),
2972  qualify_col);
2973  else
2974  {
2975  /* Treat like a Param */
2976  if (context->params_list)
2977  {
2978  int pindex = 0;
2979  ListCell *lc;
2980 
2981  /* find its index in params_list */
2982  foreach(lc, *context->params_list)
2983  {
2984  pindex++;
2985  if (equal(node, (Node *) lfirst(lc)))
2986  break;
2987  }
2988  if (lc == NULL)
2989  {
2990  /* not in list, so add it */
2991  pindex++;
2992  *context->params_list = lappend(*context->params_list, node);
2993  }
2994 
2995  printRemoteParam(pindex, node->vartype, node->vartypmod, context);
2996  }
2997  else
2998  {
2999  printRemotePlaceholder(node->vartype, node->vartypmod, context);
3000  }
3001  }
3002 }
3003 
3004 /*
3005  * Deparse given constant value into context->buf.
3006  *
3007  * This function has to be kept in sync with ruleutils.c's get_const_expr.
3008  *
3009  * As in that function, showtype can be -1 to never show "::typename"
3010  * decoration, +1 to always show it, or 0 to show it only if the constant
3011  * wouldn't be assumed to be the right type by default.
3012  *
3013  * In addition, this code allows showtype to be -2 to indicate that we should
3014  * not show "::typename" decoration if the constant is printed as an untyped
3015  * literal or NULL (while in other cases, behaving as for showtype == 0).
3016  */
3017 static void
3018 deparseConst(Const *node, deparse_expr_cxt *context, int showtype)
3019 {
3020  StringInfo buf = context->buf;
3021  Oid typoutput;
3022  bool typIsVarlena;
3023  char *extval;
3024  bool isfloat = false;
3025  bool isstring = false;
3026  bool needlabel;
3027 
3028  if (node->constisnull)
3029  {
3030  appendStringInfoString(buf, "NULL");
3031  if (showtype >= 0)
3032  appendStringInfo(buf, "::%s",
3033  deparse_type_name(node->consttype,
3034  node->consttypmod));
3035  return;
3036  }
3037 
3038  getTypeOutputInfo(node->consttype,
3039  &typoutput, &typIsVarlena);
3040  extval = OidOutputFunctionCall(typoutput, node->constvalue);
3041 
3042  switch (node->consttype)
3043  {
3044  case INT2OID:
3045  case INT4OID:
3046  case INT8OID:
3047  case OIDOID:
3048  case FLOAT4OID:
3049  case FLOAT8OID:
3050  case NUMERICOID:
3051  {
3052  /*
3053  * No need to quote unless it's a special value such as 'NaN'.
3054  * See comments in get_const_expr().
3055  */
3056  if (strspn(extval, "0123456789+-eE.") == strlen(extval))
3057  {
3058  if (extval[0] == '+' || extval[0] == '-')
3059  appendStringInfo(buf, "(%s)", extval);
3060  else
3061  appendStringInfoString(buf, extval);
3062  if (strcspn(extval, "eE.") != strlen(extval))
3063  isfloat = true; /* it looks like a float */
3064  }
3065  else
3066  appendStringInfo(buf, "'%s'", extval);
3067  }
3068  break;
3069  case BITOID:
3070  case VARBITOID:
3071  appendStringInfo(buf, "B'%s'", extval);
3072  break;
3073  case BOOLOID:
3074  if (strcmp(extval, "t") == 0)
3075  appendStringInfoString(buf, "true");
3076  else
3077  appendStringInfoString(buf, "false");
3078  break;
3079  default:
3080  deparseStringLiteral(buf, extval);
3081  isstring = true;
3082  break;
3083  }
3084 
3085  pfree(extval);
3086 
3087  if (showtype == -1)
3088  return; /* never print type label */
3089 
3090  /*
3091  * For showtype == 0, append ::typename unless the constant will be
3092  * implicitly typed as the right type when it is read in.
3093  *
3094  * XXX this code has to be kept in sync with the behavior of the parser,
3095  * especially make_const.
3096  */
3097  switch (node->consttype)
3098  {
3099  case BOOLOID:
3100  case INT4OID:
3101  case UNKNOWNOID:
3102  needlabel = false;
3103  break;
3104  case NUMERICOID:
3105  needlabel = !isfloat || (node->consttypmod >= 0);
3106  break;
3107  default:
3108  if (showtype == -2)
3109  {
3110  /* label unless we printed it as an untyped string */
3111  needlabel = !isstring;
3112  }
3113  else
3114  needlabel = true;
3115  break;
3116  }
3117  if (needlabel || showtype > 0)
3118  appendStringInfo(buf, "::%s",
3119  deparse_type_name(node->consttype,
3120  node->consttypmod));
3121 }
3122 
3123 /*
3124  * Deparse given Param node.
3125  *
3126  * If we're generating the query "for real", add the Param to
3127  * context->params_list if it's not already present, and then use its index
3128  * in that list as the remote parameter number. During EXPLAIN, there's
3129  * no need to identify a parameter number.
3130  */
3131 static void
3132 deparseParam(Param *node, deparse_expr_cxt *context)
3133 {
3134  if (context->params_list)
3135  {
3136  int pindex = 0;
3137  ListCell *lc;
3138 
3139  /* find its index in params_list */
3140  foreach(lc, *context->params_list)
3141  {
3142  pindex++;
3143  if (equal(node, (Node *) lfirst(lc)))
3144  break;
3145  }
3146  if (lc == NULL)
3147  {
3148  /* not in list, so add it */
3149  pindex++;
3150  *context->params_list = lappend(*context->params_list, node);
3151  }
3152 
3153  printRemoteParam(pindex, node->paramtype, node->paramtypmod, context);
3154  }
3155  else
3156  {
3157  printRemotePlaceholder(node->paramtype, node->paramtypmod, context);
3158  }
3159 }
3160 
3161 /*
3162  * Deparse a container subscript expression.
3163  */
3164 static void
3165 deparseSubscriptingRef(SubscriptingRef *node, deparse_expr_cxt *context)
3166 {
3167  StringInfo buf = context->buf;
3168  ListCell *lowlist_item;
3169  ListCell *uplist_item;
3170 
3171  /* Always parenthesize the expression. */
3172  appendStringInfoChar(buf, '(');
3173 
3174  /*
3175  * Deparse referenced array expression first. If that expression includes
3176  * a cast, we have to parenthesize to prevent the array subscript from
3177  * being taken as typename decoration. We can avoid that in the typical
3178  * case of subscripting a Var, but otherwise do it.
3179  */
3180  if (IsA(node->refexpr, Var))
3181  deparseExpr(node->refexpr, context);
3182  else
3183  {
3184  appendStringInfoChar(buf, '(');
3185  deparseExpr(node->refexpr, context);
3186  appendStringInfoChar(buf, ')');
3187  }
3188 
3189  /* Deparse subscript expressions. */
3190  lowlist_item = list_head(node->reflowerindexpr); /* could be NULL */
3191  foreach(uplist_item, node->refupperindexpr)
3192  {
3193  appendStringInfoChar(buf, '[');
3194  if (lowlist_item)
3195  {
3196  deparseExpr(lfirst(lowlist_item), context);
3197  appendStringInfoChar(buf, ':');
3198  lowlist_item = lnext(node->reflowerindexpr, lowlist_item);
3199  }
3200  deparseExpr(lfirst(uplist_item), context);
3201  appendStringInfoChar(buf, ']');
3202  }
3203 
3204  appendStringInfoChar(buf, ')');
3205 }
3206 
3207 /*
3208  * Deparse a function call.
3209  */
3210 static void
3211 deparseFuncExpr(FuncExpr *node, deparse_expr_cxt *context)
3212 {
3213  StringInfo buf = context->buf;
3214  bool use_variadic;
3215  bool first;
3216  ListCell *arg;
3217 
3218  /*
3219  * If the function call came from an implicit coercion, then just show the
3220  * first argument.
3221  */
3222  if (node->funcformat == COERCE_IMPLICIT_CAST)
3223  {
3224  deparseExpr((Expr *) linitial(node->args), context);
3225  return;
3226  }
3227 
3228  /*
3229  * If the function call came from a cast, then show the first argument
3230  * plus an explicit cast operation.
3231  */
3232  if (node->funcformat == COERCE_EXPLICIT_CAST)
3233  {
3234  Oid rettype = node->funcresulttype;
3235  int32 coercedTypmod;
3236 
3237  /* Get the typmod if this is a length-coercion function */
3238  (void) exprIsLengthCoercion((Node *) node, &coercedTypmod);
3239 
3240  deparseExpr((Expr *) linitial(node->args), context);
3241  appendStringInfo(buf, "::%s",
3242  deparse_type_name(rettype, coercedTypmod));
3243  return;
3244  }
3245 
3246  /* Check if need to print VARIADIC (cf. ruleutils.c) */
3247  use_variadic = node->funcvariadic;
3248 
3249  /*
3250  * Normal function: display as proname(args).
3251  */
3252  appendFunctionName(node->funcid, context);
3253  appendStringInfoChar(buf, '(');
3254 
3255  /* ... and all the arguments */
3256  first = true;
3257  foreach(arg, node->args)
3258  {
3259  if (!first)
3260  appendStringInfoString(buf, ", ");
3261  if (use_variadic && lnext(node->args, arg) == NULL)
3262  appendStringInfoString(buf, "VARIADIC ");
3263  deparseExpr((Expr *) lfirst(arg), context);
3264  first = false;
3265  }
3266  appendStringInfoChar(buf, ')');
3267 }
3268 
3269 /*
3270  * Deparse given operator expression. To avoid problems around
3271  * priority of operations, we always parenthesize the arguments.
3272  */
3273 static void
3274 deparseOpExpr(OpExpr *node, deparse_expr_cxt *context)
3275 {
3276  StringInfo buf = context->buf;
3277  HeapTuple tuple;
3278  Form_pg_operator form;
3279  Expr *right;
3280  bool canSuppressRightConstCast = false;
3281  char oprkind;
3282 
3283  /* Retrieve information about the operator from system catalog. */
3284  tuple = SearchSysCache1(OPEROID, ObjectIdGetDatum(node->opno));
3285  if (!HeapTupleIsValid(tuple))
3286  elog(ERROR, "cache lookup failed for operator %u", node->opno);
3287  form = (Form_pg_operator) GETSTRUCT(tuple);
3288  oprkind = form->oprkind;
3289 
3290  /* Sanity check. */
3291  Assert((oprkind == 'l' && list_length(node->args) == 1) ||
3292  (oprkind == 'b' && list_length(node->args) == 2));
3293 
3294  right = llast(node->args);
3295 
3296  /* Always parenthesize the expression. */
3297  appendStringInfoChar(buf, '(');
3298 
3299  /* Deparse left operand, if any. */
3300  if (oprkind == 'b')
3301  {
3302  Expr *left = linitial(node->args);
3303  Oid leftType = exprType((Node *) left);
3304  Oid rightType = exprType((Node *) right);
3305  bool canSuppressLeftConstCast = false;
3306 
3307  /*
3308  * When considering a binary operator, if one operand is a Const that
3309  * can be printed as a bare string literal or NULL (i.e., it will look
3310  * like type UNKNOWN to the remote parser), the Const normally
3311  * receives an explicit cast to the operator's input type. However,
3312  * in Const-to-Var comparisons where both operands are of the same
3313  * type, we prefer to suppress the explicit cast, leaving the Const's
3314  * type resolution up to the remote parser. The remote's resolution
3315  * heuristic will assume that an unknown input type being compared to
3316  * a known input type is of that known type as well.
3317  *
3318  * This hack allows some cases to succeed where a remote column is
3319  * declared with a different type in the local (foreign) table. By
3320  * emitting "foreigncol = 'foo'" not "foreigncol = 'foo'::text" or the
3321  * like, we allow the remote parser to pick an "=" operator that's
3322  * compatible with whatever type the remote column really is, such as
3323  * an enum.
3324  *
3325  * We allow cast suppression to happen only when the other operand is
3326  * a plain foreign Var. Although the remote's unknown-type heuristic
3327  * would apply to other cases just as well, we would be taking a
3328  * bigger risk that the inferred type is something unexpected. With
3329  * this restriction, if anything goes wrong it's the user's fault for
3330  * not declaring the local column with the same type as the remote
3331  * column.
3332  */
3333  if (leftType == rightType)
3334  {
3335  if (IsA(left, Const))
3336  canSuppressLeftConstCast = isPlainForeignVar(right, context);
3337  else if (IsA(right, Const))
3338  canSuppressRightConstCast = isPlainForeignVar(left, context);
3339  }
3340 
3341  if (canSuppressLeftConstCast)
3342  deparseConst((Const *) left, context, -2);
3343  else
3344  deparseExpr(left, context);
3345 
3346  appendStringInfoChar(buf, ' ');
3347  }
3348 
3349  /* Deparse operator name. */
3350  deparseOperatorName(buf, form);
3351 
3352  /* Deparse right operand. */
3353  appendStringInfoChar(buf, ' ');
3354 
3355  if (canSuppressRightConstCast)
3356  deparseConst((Const *) right, context, -2);
3357  else
3358  deparseExpr(right, context);
3359 
3360  appendStringInfoChar(buf, ')');
3361 
3362  ReleaseSysCache(tuple);
3363 }
3364 
3365 /*
3366  * Will "node" deparse as a plain foreign Var?
3367  */
3368 static bool
3369 isPlainForeignVar(Expr *node, deparse_expr_cxt *context)
3370 {
3371  /*
3372  * We allow the foreign Var to have an implicit RelabelType, mainly so
3373  * that this'll work with varchar columns. Note that deparseRelabelType
3374  * will not print such a cast, so we're not breaking the restriction that
3375  * the expression print as a plain Var. We won't risk it for an implicit
3376  * cast that requires a function, nor for non-implicit RelabelType; such
3377  * cases seem too likely to involve semantics changes compared to what
3378  * would happen on the remote side.
3379  */
3380  if (IsA(node, RelabelType) &&
3381  ((RelabelType *) node)->relabelformat == COERCE_IMPLICIT_CAST)
3382  node = ((RelabelType *) node)->arg;
3383 
3384  if (IsA(node, Var))
3385  {
3386  /*
3387  * The Var must be one that'll deparse as a foreign column reference
3388  * (cf. deparseVar).
3389  */
3390  Var *var = (Var *) node;
3391  Relids relids = context->scanrel->relids;
3392 
3393  if (bms_is_member(var->varno, relids) && var->varlevelsup == 0)
3394  return true;
3395  }
3396 
3397  return false;
3398 }
3399 
3400 /*
3401  * Print the name of an operator.
3402  */
3403 static void
3404 deparseOperatorName(StringInfo buf, Form_pg_operator opform)
3405 {
3406  char *opname;
3407 
3408  /* opname is not a SQL identifier, so we should not quote it. */
3409  opname = NameStr(opform->oprname);
3410 
3411  /* Print schema name only if it's not pg_catalog */
3412  if (opform->oprnamespace != PG_CATALOG_NAMESPACE)
3413  {
3414  const char *opnspname;
3415 
3416  opnspname = get_namespace_name(opform->oprnamespace);
3417  /* Print fully qualified operator name. */
3418  appendStringInfo(buf, "OPERATOR(%s.%s)",
3419  quote_identifier(opnspname), opname);
3420  }
3421  else
3422  {
3423  /* Just print operator name. */
3424  appendStringInfoString(buf, opname);
3425  }
3426 }
3427 
3428 /*
3429  * Deparse IS DISTINCT FROM.
3430  */
3431 static void
3432 deparseDistinctExpr(DistinctExpr *node, deparse_expr_cxt *context)
3433 {
3434  StringInfo buf = context->buf;
3435 
3436  Assert(list_length(node->args) == 2);
3437 
3438  appendStringInfoChar(buf, '(');
3439  deparseExpr(linitial(node->args), context);
3440  appendStringInfoString(buf, " IS DISTINCT FROM ");
3441  deparseExpr(lsecond(node->args), context);
3442  appendStringInfoChar(buf, ')');
3443 }
3444 
3445 /*
3446  * Deparse given ScalarArrayOpExpr expression. To avoid problems
3447  * around priority of operations, we always parenthesize the arguments.
3448  */
3449 static void
3450 deparseScalarArrayOpExpr(ScalarArrayOpExpr *node, deparse_expr_cxt *context)
3451 {
3452  StringInfo buf = context->buf;
3453  HeapTuple tuple;
3454  Form_pg_operator form;
3455  Expr *arg1;
3456  Expr *arg2;
3457 
3458  /* Retrieve information about the operator from system catalog. */
3459  tuple = SearchSysCache1(OPEROID, ObjectIdGetDatum(node->opno));
3460  if (!HeapTupleIsValid(tuple))
3461  elog(ERROR, "cache lookup failed for operator %u", node->opno);
3462  form = (Form_pg_operator) GETSTRUCT(tuple);
3463 
3464  /* Sanity check. */
3465  Assert(list_length(node->args) == 2);
3466 
3467  /* Always parenthesize the expression. */
3468  appendStringInfoChar(buf, '(');
3469 
3470  /* Deparse left operand. */
3471  arg1 = linitial(node->args);
3472  deparseExpr(arg1, context);
3473  appendStringInfoChar(buf, ' ');
3474 
3475  /* Deparse operator name plus decoration. */
3476  deparseOperatorName(buf, form);
3477  appendStringInfo(buf, " %s (", node->useOr ? "ANY" : "ALL");
3478 
3479  /* Deparse right operand. */
3480  arg2 = lsecond(node->args);
3481  deparseExpr(arg2, context);
3482 
3483  appendStringInfoChar(buf, ')');
3484 
3485  /* Always parenthesize the expression. */
3486  appendStringInfoChar(buf, ')');
3487 
3488  ReleaseSysCache(tuple);
3489 }
3490 
3491 /*
3492  * Deparse a RelabelType (binary-compatible cast) node.
3493  */
3494 static void
3495 deparseRelabelType(RelabelType *node, deparse_expr_cxt *context)
3496 {
3497  deparseExpr(node->arg, context);
3498  if (node->relabelformat != COERCE_IMPLICIT_CAST)
3499  appendStringInfo(context->buf, "::%s",
3500  deparse_type_name(node->resulttype,
3501  node->resulttypmod));
3502 }
3503 
3504 /*
3505  * Deparse a BoolExpr node.
3506  */
3507 static void
3508 deparseBoolExpr(BoolExpr *node, deparse_expr_cxt *context)
3509 {
3510  StringInfo buf = context->buf;
3511  const char *op = NULL; /* keep compiler quiet */
3512  bool first;
3513  ListCell *lc;
3514 
3515  switch (node->boolop)
3516  {
3517  case AND_EXPR:
3518  op = "AND";
3519  break;
3520  case OR_EXPR:
3521  op = "OR";
3522  break;
3523  case NOT_EXPR:
3524  appendStringInfoString(buf, "(NOT ");
3525  deparseExpr(linitial(node->args), context);
3526  appendStringInfoChar(buf, ')');
3527  return;
3528  }
3529 
3530  appendStringInfoChar(buf, '(');
3531  first = true;
3532  foreach(lc, node->args)
3533  {
3534  if (!first)
3535  appendStringInfo(buf, " %s ", op);
3536  deparseExpr((Expr *) lfirst(lc), context);
3537  first = false;
3538  }
3539  appendStringInfoChar(buf, ')');
3540 }
3541 
3542 /*
3543  * Deparse IS [NOT] NULL expression.
3544  */
3545 static void
3546 deparseNullTest(NullTest *node, deparse_expr_cxt *context)
3547 {
3548  StringInfo buf = context->buf;
3549 
3550  appendStringInfoChar(buf, '(');
3551  deparseExpr(node->arg, context);
3552 
3553  /*
3554  * For scalar inputs, we prefer to print as IS [NOT] NULL, which is
3555  * shorter and traditional. If it's a rowtype input but we're applying a
3556  * scalar test, must print IS [NOT] DISTINCT FROM NULL to be semantically
3557  * correct.
3558  */
3559  if (node->argisrow || !type_is_rowtype(exprType((Node *) node->arg)))
3560  {
3561  if (node->nulltesttype == IS_NULL)
3562  appendStringInfoString(buf, " IS NULL)");
3563  else
3564  appendStringInfoString(buf, " IS NOT NULL)");
3565  }
3566  else
3567  {
3568  if (node->nulltesttype == IS_NULL)
3569  appendStringInfoString(buf, " IS NOT DISTINCT FROM NULL)");
3570  else
3571  appendStringInfoString(buf, " IS DISTINCT FROM NULL)");
3572  }
3573 }
3574 
3575 /*
3576  * Deparse CASE expression
3577  */
3578 static void
3579 deparseCaseExpr(CaseExpr *node, deparse_expr_cxt *context)
3580 {
3581  StringInfo buf = context->buf;
3582  ListCell *lc;
3583 
3584  appendStringInfoString(buf, "(CASE");
3585 
3586  /* If this is a CASE arg WHEN then emit the arg expression */
3587  if (node->arg != NULL)
3588  {
3589  appendStringInfoChar(buf, ' ');
3590  deparseExpr(node->arg, context);
3591  }
3592 
3593  /* Add each condition/result of the CASE clause */
3594  foreach(lc, node->args)
3595  {
3596  CaseWhen *whenclause = (CaseWhen *) lfirst(lc);
3597 
3598  /* WHEN */
3599  appendStringInfoString(buf, " WHEN ");
3600  if (node->arg == NULL) /* CASE WHEN */
3601  deparseExpr(whenclause->expr, context);
3602  else /* CASE arg WHEN */
3603  {
3604  /* Ignore the CaseTestExpr and equality operator. */
3605  deparseExpr(lsecond(castNode(OpExpr, whenclause->expr)->args),
3606  context);
3607  }
3608 
3609  /* THEN */
3610  appendStringInfoString(buf, " THEN ");
3611  deparseExpr(whenclause->result, context);
3612  }
3613 
3614  /* add ELSE if present */
3615  if (node->defresult != NULL)
3616  {
3617  appendStringInfoString(buf, " ELSE ");
3618  deparseExpr(node->defresult, context);
3619  }
3620 
3621  /* append END */
3622  appendStringInfoString(buf, " END)");
3623 }
3624 
3625 /*
3626  * Deparse ARRAY[...] construct.
3627  */
3628 static void
3629 deparseArrayExpr(ArrayExpr *node, deparse_expr_cxt *context)
3630 {
3631  StringInfo buf = context->buf;
3632  bool first = true;
3633  ListCell *lc;
3634 
3635  appendStringInfoString(buf, "ARRAY[");
3636  foreach(lc, node->elements)
3637  {
3638  if (!first)
3639  appendStringInfoString(buf, ", ");
3640  deparseExpr(lfirst(lc), context);
3641  first = false;
3642  }
3643  appendStringInfoChar(buf, ']');
3644 
3645  /* If the array is empty, we need an explicit cast to the array type. */
3646  if (node->elements == NIL)
3647  appendStringInfo(buf, "::%s",
3648  deparse_type_name(node->array_typeid, -1));
3649 }
3650 
3651 /*
3652  * Deparse an Aggref node.
3653  */
3654 static void
3655 deparseAggref(Aggref *node, deparse_expr_cxt *context)
3656 {
3657  StringInfo buf = context->buf;
3658  bool use_variadic;
3659 
3660  /* Only basic, non-split aggregation accepted. */
3661  Assert(node->aggsplit == AGGSPLIT_SIMPLE);
3662 
3663  /* Check if need to print VARIADIC (cf. ruleutils.c) */
3664  use_variadic = node->aggvariadic;
3665 
3666  /* Find aggregate name from aggfnoid which is a pg_proc entry */
3667  appendFunctionName(node->aggfnoid, context);
3668  appendStringInfoChar(buf, '(');
3669 
3670  /* Add DISTINCT */
3671  appendStringInfoString(buf, (node->aggdistinct != NIL) ? "DISTINCT " : "");
3672 
3673  if (AGGKIND_IS_ORDERED_SET(node->aggkind))
3674  {
3675  /* Add WITHIN GROUP (ORDER BY ..) */
3676  ListCell *arg;
3677  bool first = true;
3678 
3679  Assert(!node->aggvariadic);
3680  Assert(node->aggorder != NIL);
3681 
3682  foreach(arg, node->aggdirectargs)
3683  {
3684  if (!first)
3685  appendStringInfoString(buf, ", ");
3686  first = false;
3687 
3688  deparseExpr((Expr *) lfirst(arg), context);
3689  }
3690 
3691  appendStringInfoString(buf, ") WITHIN GROUP (ORDER BY ");
3692  appendAggOrderBy(node->aggorder, node->args, context);
3693  }
3694  else
3695  {
3696  /* aggstar can be set only in zero-argument aggregates */
3697  if (node->aggstar)
3698  appendStringInfoChar(buf, '*');
3699  else
3700  {
3701  ListCell *arg;
3702  bool first = true;
3703 
3704  /* Add all the arguments */
3705  foreach(arg, node->args)
3706  {
3707  TargetEntry *tle = (TargetEntry *) lfirst(arg);
3708  Node *n = (Node *) tle->expr;
3709 
3710  if (tle->resjunk)
3711  continue;
3712 
3713  if (!first)
3714  appendStringInfoString(buf, ", ");
3715  first = false;
3716 
3717  /* Add VARIADIC */
3718  if (use_variadic && lnext(node->args, arg) == NULL)
3719  appendStringInfoString(buf, "VARIADIC ");
3720 
3721  deparseExpr((Expr *) n, context);
3722  }
3723  }
3724 
3725  /* Add ORDER BY */
3726  if (node->aggorder != NIL)
3727  {
3728  appendStringInfoString(buf, " ORDER BY ");
3729  appendAggOrderBy(node->aggorder, node->args, context);
3730  }
3731  }
3732 
3733  /* Add FILTER (WHERE ..) */
3734  if (node->aggfilter != NULL)
3735  {
3736  appendStringInfoString(buf, ") FILTER (WHERE ");
3737  deparseExpr((Expr *) node->aggfilter, context);
3738  }
3739 
3740  appendStringInfoChar(buf, ')');
3741 }
3742 
3743 /*
3744  * Append ORDER BY within aggregate function.
3745  */
3746 static void
3747 appendAggOrderBy(List *orderList, List *targetList, deparse_expr_cxt *context)
3748 {
3749  StringInfo buf = context->buf;
3750  ListCell *lc;
3751  bool first = true;
3752 
3753  foreach(lc, orderList)
3754  {
3755  SortGroupClause *srt = (SortGroupClause *) lfirst(lc);
3756  Node *sortexpr;
3757 
3758  if (!first)
3759  appendStringInfoString(buf, ", ");
3760  first = false;
3761 
3762  /* Deparse the sort expression proper. */
3763  sortexpr = deparseSortGroupClause(srt->tleSortGroupRef, targetList,
3764  false, context);
3765  /* Add decoration as needed. */
3766  appendOrderBySuffix(srt->sortop, exprType(sortexpr), srt->nulls_first,
3767  context);
3768  }
3769 }
3770 
3771 /*
3772  * Append the ASC, DESC, USING <OPERATOR> and NULLS FIRST / NULLS LAST parts
3773  * of an ORDER BY clause.
3774  */
3775 static void
3776 appendOrderBySuffix(Oid sortop, Oid sortcoltype, bool nulls_first,
3777  deparse_expr_cxt *context)
3778 {
3779  StringInfo buf = context->buf;
3780  TypeCacheEntry *typentry;
3781 
3782  /* See whether operator is default < or > for sort expr's datatype. */
3783  typentry = lookup_type_cache(sortcoltype,
3784  TYPECACHE_LT_OPR | TYPECACHE_GT_OPR);
3785 
3786  if (sortop == typentry->lt_opr)
3787  appendStringInfoString(buf, " ASC");
3788  else if (sortop == typentry->gt_opr)
3789  appendStringInfoString(buf, " DESC");
3790  else
3791  {
3792  HeapTuple opertup;
3793  Form_pg_operator operform;
3794 
3795  appendStringInfoString(buf, " USING ");
3796 
3797  /* Append operator name. */
3798  opertup = SearchSysCache1(OPEROID, ObjectIdGetDatum(sortop));
3799  if (!HeapTupleIsValid(opertup))
3800  elog(ERROR, "cache lookup failed for operator %u", sortop);
3801  operform = (Form_pg_operator) GETSTRUCT(opertup);
3802  deparseOperatorName(buf, operform);
3803  ReleaseSysCache(opertup);
3804  }
3805 
3806  if (nulls_first)
3807  appendStringInfoString(buf, " NULLS FIRST");
3808  else
3809  appendStringInfoString(buf, " NULLS LAST");
3810 }
3811 
3812 /*
3813  * Print the representation of a parameter to be sent to the remote side.
3814  *
3815  * Note: we always label the Param's type explicitly rather than relying on
3816  * transmitting a numeric type OID in PQsendQueryParams(). This allows us to
3817  * avoid assuming that types have the same OIDs on the remote side as they
3818  * do locally --- they need only have the same names.
3819  */
3820 static void
3821 printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod,
3822  deparse_expr_cxt *context)
3823 {
3824  StringInfo buf = context->buf;
3825  char *ptypename = deparse_type_name(paramtype, paramtypmod);
3826 
3827  appendStringInfo(buf, "$%d::%s", paramindex, ptypename);
3828 }
3829 
3830 /*
3831  * Print the representation of a placeholder for a parameter that will be
3832  * sent to the remote side at execution time.
3833  *
3834  * This is used when we're just trying to EXPLAIN the remote query.
3835  * We don't have the actual value of the runtime parameter yet, and we don't
3836  * want the remote planner to generate a plan that depends on such a value
3837  * anyway. Thus, we can't do something simple like "$1::paramtype".
3838  * Instead, we emit "((SELECT null::paramtype)::paramtype)".
3839  * In all extant versions of Postgres, the planner will see that as an unknown
3840  * constant value, which is what we want. This might need adjustment if we
3841  * ever make the planner flatten scalar subqueries. Note: the reason for the
3842  * apparently useless outer cast is to ensure that the representation as a
3843  * whole will be parsed as an a_expr and not a select_with_parens; the latter
3844  * would do the wrong thing in the context "x = ANY(...)".
3845  */
3846 static void
3847 printRemotePlaceholder(Oid paramtype, int32 paramtypmod,
3848  deparse_expr_cxt *context)
3849 {
3850  StringInfo buf = context->buf;
3851  char *ptypename = deparse_type_name(paramtype, paramtypmod);
3852 
3853  appendStringInfo(buf, "((SELECT null::%s)::%s)", ptypename, ptypename);
3854 }
3855 
3856 /*
3857  * Deparse GROUP BY clause.
3858  */
3859 static void
3860 appendGroupByClause(List *tlist, deparse_expr_cxt *context)
3861 {
3862  StringInfo buf = context->buf;
3863  Query *query = context->root->parse;
3864  ListCell *lc;
3865  bool first = true;
3866 
3867  /* Nothing to be done, if there's no GROUP BY clause in the query. */
3868  if (!query->groupClause)
3869  return;
3870 
3871  appendStringInfoString(buf, " GROUP BY ");
3872 
3873  /*
3874  * Queries with grouping sets are not pushed down, so we don't expect
3875  * grouping sets here.
3876  */
3877  Assert(!query->groupingSets);
3878 
3879  /*
3880  * We intentionally print query->groupClause not processed_groupClause,
3881  * leaving it to the remote planner to get rid of any redundant GROUP BY
3882  * items again. This is necessary in case processed_groupClause reduced
3883  * to empty, and in any case the redundancy situation on the remote might
3884  * be different than what we think here.
3885  */
3886  foreach(lc, query->groupClause)
3887  {
3888  SortGroupClause *grp = (SortGroupClause *) lfirst(lc);
3889 
3890  if (!first)
3891  appendStringInfoString(buf, ", ");
3892  first = false;
3893 
3894  deparseSortGroupClause(grp->tleSortGroupRef, tlist, true, context);
3895  }
3896 }
3897 
3898 /*
3899  * Deparse ORDER BY clause defined by the given pathkeys.
3900  *
3901  * The clause should use Vars from context->scanrel if !has_final_sort,
3902  * or from context->foreignrel's targetlist if has_final_sort.
3903  *
3904  * We find a suitable pathkey expression (some earlier step
3905  * should have verified that there is one) and deparse it.
3906  */
3907 static void
3908 appendOrderByClause(List *pathkeys, bool has_final_sort,
3909  deparse_expr_cxt *context)
3910 {
3911  ListCell *lcell;
3912  int nestlevel;
3913  StringInfo buf = context->buf;
3914  bool gotone = false;
3915 
3916  /* Make sure any constants in the exprs are printed portably */
3917  nestlevel = set_transmission_modes();
3918 
3919  foreach(lcell, pathkeys)
3920  {
3921  PathKey *pathkey = lfirst(lcell);
3922  EquivalenceMember *em;
3923  Expr *em_expr;
3924  Oid oprid;
3925 
3926  if (has_final_sort)
3927  {
3928  /*
3929  * By construction, context->foreignrel is the input relation to
3930  * the final sort.
3931  */
3932  em = find_em_for_rel_target(context->root,
3933  pathkey->pk_eclass,
3934  context->foreignrel);
3935  }
3936  else
3937  em = find_em_for_rel(context->root,
3938  pathkey->pk_eclass,
3939  context->scanrel);
3940 
3941  /*
3942  * We don't expect any error here; it would mean that shippability
3943  * wasn't verified earlier. For the same reason, we don't recheck
3944  * shippability of the sort operator.
3945  */
3946  if (em == NULL)
3947  elog(ERROR, "could not find pathkey item to sort");
3948 
3949  em_expr = em->em_expr;
3950 
3951  /*
3952  * If the member is a Const expression then we needn't add it to the
3953  * ORDER BY clause. This can happen in UNION ALL queries where the
3954  * union child targetlist has a Const. Adding these would be
3955  * wasteful, but also, for INT columns, an integer literal would be
3956  * seen as an ordinal column position rather than a value to sort by.
3957  * deparseConst() does have code to handle this, but it seems less
3958  * effort on all accounts just to skip these for ORDER BY clauses.
3959  */
3960  if (IsA(em_expr, Const))
3961  continue;
3962 
3963  if (!gotone)
3964  {
3965  appendStringInfoString(buf, " ORDER BY ");
3966  gotone = true;
3967  }
3968  else
3969  appendStringInfoString(buf, ", ");
3970 
3971  /*
3972  * Lookup the operator corresponding to the strategy in the opclass.
3973  * The datatype used by the opfamily is not necessarily the same as
3974  * the expression type (for array types for example).
3975  */
3976  oprid = get_opfamily_member(pathkey->pk_opfamily,
3977  em->em_datatype,
3978  em->em_datatype,
3979  pathkey->pk_strategy);
3980  if (!OidIsValid(oprid))
3981  elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
3982  pathkey->pk_strategy, em->em_datatype, em->em_datatype,
3983  pathkey->pk_opfamily);
3984 
3985  deparseExpr(em_expr, context);
3986 
3987  /*
3988  * Here we need to use the expression's actual type to discover
3989  * whether the desired operator will be the default or not.
3990  */
3991  appendOrderBySuffix(oprid, exprType((Node *) em_expr),
3992  pathkey->pk_nulls_first, context);
3993 
3994  }
3995  reset_transmission_modes(nestlevel);
3996 }
3997 
3998 /*
3999  * Deparse LIMIT/OFFSET clause.
4000  */
4001 static void
4002 appendLimitClause(deparse_expr_cxt *context)
4003 {
4004  PlannerInfo *root = context->root;
4005  StringInfo buf = context->buf;
4006  int nestlevel;
4007 
4008  /* Make sure any constants in the exprs are printed portably */
4009  nestlevel = set_transmission_modes();
4010 
4011  if (root->parse->limitCount)
4012  {
4013  appendStringInfoString(buf, " LIMIT ");
4014  deparseExpr((Expr *) root->parse->limitCount, context);
4015  }
4016  if (root->parse->limitOffset)
4017  {
4018  appendStringInfoString(buf, " OFFSET ");
4019  deparseExpr((Expr *) root->parse->limitOffset, context);
4020  }
4021 
4022  reset_transmission_modes(nestlevel);
4023 }
4024 
4025 /*
4026  * appendFunctionName
4027  * Deparses function name from given function oid.
4028  */
4029 static void
4030 appendFunctionName(Oid funcid, deparse_expr_cxt *context)
4031 {
4032  StringInfo buf = context->buf;
4033  HeapTuple proctup;
4034  Form_pg_proc procform;
4035  const char *proname;
4036 
4037  proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
4038  if (!HeapTupleIsValid(proctup))
4039  elog(ERROR, "cache lookup failed for function %u", funcid);
4040  procform = (Form_pg_proc) GETSTRUCT(proctup);
4041 
4042  /* Print schema name only if it's not pg_catalog */
4043  if (procform->pronamespace != PG_CATALOG_NAMESPACE)
4044  {
4045  const char *schemaname;
4046 
4047  schemaname = get_namespace_name(procform->pronamespace);
4048  appendStringInfo(buf, "%s.", quote_identifier(schemaname));
4049  }
4050 
4051  /* Always print the function name */
4052  proname = NameStr(procform->proname);
4053  appendStringInfoString(buf, quote_identifier(proname));
4054 
4055  ReleaseSysCache(proctup);
4056 }
4057 
4058 /*
4059  * Appends a sort or group clause.
4060  *
4061  * Like get_rule_sortgroupclause(), returns the expression tree, so caller
4062  * need not find it again.
4063  */
4064 static Node *
4065 deparseSortGroupClause(Index ref, List *tlist, bool force_colno,
4066  deparse_expr_cxt *context)
4067 {
4068  StringInfo buf = context->buf;
4069  TargetEntry *tle;
4070  Expr *expr;
4071 
4072  tle = get_sortgroupref_tle(ref, tlist);
4073  expr = tle->expr;
4074 
4075  if (force_colno)
4076  {
4077  /* Use column-number form when requested by caller. */
4078  Assert(!tle->resjunk);
4079  appendStringInfo(buf, "%d", tle->resno);
4080  }
4081  else if (expr && IsA(expr, Const))
4082  {
4083  /*
4084  * Force a typecast here so that we don't emit something like "GROUP
4085  * BY 2", which will be misconstrued as a column position rather than
4086  * a constant.
4087  */
4088  deparseConst((Const *) expr, context, 1);
4089  }
4090  else if (!expr || IsA(expr, Var))
4091  deparseExpr(expr, context);
4092  else
4093  {
4094  /* Always parenthesize the expression. */
4095  appendStringInfoChar(buf, '(');
4096  deparseExpr(expr, context);
4097  appendStringInfoChar(buf, ')');
4098  }
4099 
4100  return (Node *) expr;
4101 }
4102 
4103 
4104 /*
4105  * Returns true if given Var is deparsed as a subquery output column, in
4106  * which case, *relno and *colno are set to the IDs for the relation and
4107  * column alias to the Var provided by the subquery.
4108  */
4109 static bool
4110 is_subquery_var(Var *node, RelOptInfo *foreignrel, int *relno, int *colno)
4111 {
4112  PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
4113  RelOptInfo *outerrel = fpinfo->outerrel;
4114  RelOptInfo *innerrel = fpinfo->innerrel;
4115 
4116  /* Should only be called in these cases. */
4117  Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
4118 
4119  /*
4120  * If the given relation isn't a join relation, it doesn't have any lower
4121  * subqueries, so the Var isn't a subquery output column.
4122  */
4123  if (!IS_JOIN_REL(foreignrel))
4124  return false;
4125 
4126  /*
4127  * If the Var doesn't belong to any lower subqueries, it isn't a subquery
4128  * output column.
4129  */
4130  if (!bms_is_member(node->varno, fpinfo->lower_subquery_rels))
4131  return false;
4132 
4133  if (bms_is_member(node->varno, outerrel->relids))
4134  {
4135  /*
4136  * If outer relation is deparsed as a subquery, the Var is an output
4137  * column of the subquery; get the IDs for the relation/column alias.
4138  */
4139  if (fpinfo->make_outerrel_subquery)
4140  {
4141  get_relation_column_alias_ids(node, outerrel, relno, colno);
4142  return true;
4143  }
4144 
4145  /* Otherwise, recurse into the outer relation. */
4146  return is_subquery_var(node, outerrel, relno, colno);
4147  }
4148  else
4149  {
4150  Assert(bms_is_member(node->varno, innerrel->relids));
4151 
4152  /*
4153  * If inner relation is deparsed as a subquery, the Var is an output
4154  * column of the subquery; get the IDs for the relation/column alias.
4155  */
4156  if (fpinfo->make_innerrel_subquery)
4157  {
4158  get_relation_column_alias_ids(node, innerrel, relno, colno);
4159  return true;
4160  }
4161 
4162  /* Otherwise, recurse into the inner relation. */
4163  return is_subquery_var(node, innerrel, relno, colno);
4164  }
4165 }
4166 
4167 /*
4168  * Get the IDs for the relation and column alias to given Var belonging to
4169  * given relation, which are returned into *relno and *colno.
4170  */
4171 static void
4172 get_relation_column_alias_ids(Var *node, RelOptInfo *foreignrel,
4173  int *relno, int *colno)
4174 {
4175  PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
4176  int i;
4177  ListCell *lc;
4178 
4179  /* Get the relation alias ID */
4180  *relno = fpinfo->relation_index;
4181 
4182  /* Get the column alias ID */
4183  i = 1;
4184  foreach(lc, foreignrel->reltarget->exprs)
4185  {
4186  Var *tlvar = (Var *) lfirst(lc);
4187 
4188  /*
4189  * Match reltarget entries only on varno/varattno. Ideally there
4190  * would be some cross-check on varnullingrels, but it's unclear what
4191  * to do exactly; we don't have enough context to know what that value
4192  * should be.
4193  */
4194  if (IsA(tlvar, Var) &&
4195  tlvar->varno == node->varno &&
4196  tlvar->varattno == node->varattno)
4197  {
4198  *colno = i;
4199  return;
4200  }
4201  i++;
4202  }
4203 
4204  /* Shouldn't get here */
4205  elog(ERROR, "unexpected expression in subquery output");
4206 }
AttrNumber
int16 AttrNumber
Definition: attnum.h:21
bms_next_member
int bms_next_member(const Bitmapset *a, int prevbit)
Definition: bitmapset.c:1306
bms_free
void bms_free(Bitmapset *a)
Definition: bitmapset.c:239
bms_is_member
bool bms_is_member(int x, const Bitmapset *a)
Definition: bitmapset.c:510
bms_make_singleton
Bitmapset * bms_make_singleton(int x)
Definition: bitmapset.c:216
bms_add_member
Bitmapset * bms_add_member(Bitmapset *a, int x)
Definition: bitmapset.c:815
bms_membership
BMS_Membership bms_membership(const Bitmapset *a)
Definition: bitmapset.c:781
BMS_MULTIPLE
@ BMS_MULTIPLE
Definition: bitmapset.h:73
FORMAT_TYPE_TYPEMOD_GIVEN
#define FORMAT_TYPE_TYPEMOD_GIVEN
Definition: builtins.h:124
FORMAT_TYPE_FORCE_QUALIFY
#define FORMAT_TYPE_FORCE_QUALIFY
Definition: builtins.h:126
NameStr
#define NameStr(name)
Definition: c.h:700
bits16
uint16 bits16
Definition: c.h:493
Assert
#define Assert(condition)
Definition: c.h:812
ESCAPE_STRING_SYNTAX
#define ESCAPE_STRING_SYNTAX
Definition: c.h:1120
SQL_STR_DOUBLE
#define SQL_STR_DOUBLE(ch, escape_backslash)
Definition: c.h:1117
int32
int32_t int32
Definition: c.h:481
Index
unsigned int Index
Definition: c.h:568
OidIsValid
#define OidIsValid(objectId)
Definition: c.h:729
contain_mutable_functions
bool contain_mutable_functions(Node *clause)
Definition: clauses.c:369
defGetString
char * defGetString(DefElem *def)
Definition: define.c:48
deparseRangeTblRef
static void deparseRangeTblRef(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel, bool make_subquery, Index ignore_rel, List **ignore_conds, List **additional_conds, List **params_list)
Definition: deparse.c:2006
deparseCaseExpr
static void deparseCaseExpr(CaseExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3579
deparseAnalyzeSizeSql
void deparseAnalyzeSizeSql(StringInfo buf, Relation rel)
Definition: deparse.c:2497
deparseBoolExpr
static void deparseBoolExpr(BoolExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3508
appendGroupByClause
static void appendGroupByClause(List *tlist, deparse_expr_cxt *context)
Definition: deparse.c:3860
deparseTargetList
static void deparseTargetList(StringInfo buf, RangeTblEntry *rte, Index rtindex, Relation rel, bool is_returning, Bitmapset *attrs_used, bool qualify_col, List **retrieved_attrs)
Definition: deparse.c:1403
SUBQUERY_REL_ALIAS_PREFIX
#define SUBQUERY_REL_ALIAS_PREFIX
Definition: deparse.c:112
deparseFromExpr
static void deparseFromExpr(List *quals, deparse_expr_cxt *context)
Definition: deparse.c:1371
deparseSortGroupClause
static Node * deparseSortGroupClause(Index ref, List *tlist, bool force_colno, deparse_expr_cxt *context)
Definition: deparse.c:4065
deparseLockingClause
static void deparseLockingClause(deparse_expr_cxt *context)
Definition: deparse.c:1479
get_jointype_name
const char * get_jointype_name(JoinType jointype)
Definition: deparse.c:1639
deparseAnalyzeInfoSql
void deparseAnalyzeInfoSql(StringInfo buf, Relation rel)
Definition: deparse.c:2519
deparseAggref
static void deparseAggref(Aggref *node, deparse_expr_cxt *context)
Definition: deparse.c:3655
appendOrderBySuffix
static void appendOrderBySuffix(Oid sortop, Oid sortcoltype, bool nulls_first, deparse_expr_cxt *context)
Definition: deparse.c:3776
deparseDirectDeleteSql
void deparseDirectDeleteSql(StringInfo buf, PlannerInfo *root, Index rtindex, Relation rel, RelOptInfo *foreignrel, List *remote_conds, List **params_list, List *returningList, List **retrieved_attrs)
Definition: deparse.c:2389
REL_ALIAS_PREFIX
#define REL_ALIAS_PREFIX
Definition: deparse.c:108
deparseDirectUpdateSql
void deparseDirectUpdateSql(StringInfo buf, PlannerInfo *root, Index rtindex, Relation rel, RelOptInfo *foreignrel, List *targetlist, List *targetAttrs, List *remote_conds, List **params_list, List *returningList, List **retrieved_attrs)
Definition: deparse.c:2274
deparse_expr_cxt
struct deparse_expr_cxt deparse_expr_cxt
get_relation_column_alias_ids
static void get_relation_column_alias_ids(Var *node, RelOptInfo *foreignrel, int *relno, int *colno)
Definition: deparse.c:4172
FDWCollateState
FDWCollateState
Definition: deparse.c:79
FDW_COLLATE_SAFE
@ FDW_COLLATE_SAFE
Definition: deparse.c:83
FDW_COLLATE_UNSAFE
@ FDW_COLLATE_UNSAFE
Definition: deparse.c:84
FDW_COLLATE_NONE
@ FDW_COLLATE_NONE
Definition: deparse.c:80
printRemoteParam
static void printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod, deparse_expr_cxt *context)
Definition: deparse.c:3821
is_subquery_var
static bool is_subquery_var(Var *node, RelOptInfo *foreignrel, int *relno, int *colno)
Definition: deparse.c:4110
is_foreign_param
bool is_foreign_param(PlannerInfo *root, RelOptInfo *baserel, Expr *expr)
Definition: deparse.c:1080
printRemotePlaceholder
static void printRemotePlaceholder(Oid paramtype, int32 paramtypmod, deparse_expr_cxt *context)
Definition: deparse.c:3847
appendOrderByClause
static void appendOrderByClause(List *pathkeys, bool has_final_sort, deparse_expr_cxt *context)
Definition: deparse.c:3908
foreign_expr_walker
static bool foreign_expr_walker(Node *node, foreign_glob_cxt *glob_cxt, foreign_loc_cxt *outer_cxt, foreign_loc_cxt *case_arg_cxt)
Definition: deparse.c:310
deparseColumnRef
static void deparseColumnRef(StringInfo buf, int varno, int varattno, RangeTblEntry *rte, bool qualify_col)
Definition: deparse.c:2679
deparseRelabelType
static void deparseRelabelType(RelabelType *node, deparse_expr_cxt *context)
Definition: deparse.c:3495
deparseNullTest
static void deparseNullTest(NullTest *node, deparse_expr_cxt *context)
Definition: deparse.c:3546
deparseOperatorName
static void deparseOperatorName(StringInfo buf, Form_pg_operator opform)
Definition: deparse.c:3404
deparseOpExpr
static void deparseOpExpr(OpExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3274
deparseConst
static void deparseConst(Const *node, deparse_expr_cxt *context, int showtype)
Definition: deparse.c:3018
isPlainForeignVar
static bool isPlainForeignVar(Expr *node, deparse_expr_cxt *context)
Definition: deparse.c:3369
deparseDistinctExpr
static void deparseDistinctExpr(DistinctExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3432
deparseSelectStmtForRel
void deparseSelectStmtForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *rel, List *tlist, List *remote_conds, List *pathkeys, bool has_final_sort, bool has_limit, bool is_subquery, List **retrieved_attrs, List **params_list)
Definition: deparse.c:1231
deparseFuncExpr
static void deparseFuncExpr(FuncExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3211
deparseStringLiteral
void deparseStringLiteral(StringInfo buf, const char *val)
Definition: deparse.c:2847
rebuildInsertSql
void rebuildInsertSql(StringInfo buf, Relation rel, char *orig_query, List *target_attrs, int values_end_len, int num_params, int num_rows)
Definition: deparse.c:2154
foreign_glob_cxt
struct foreign_glob_cxt foreign_glob_cxt
deparseArrayExpr
static void deparseArrayExpr(ArrayExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3629
deparseInsertSql
void deparseInsertSql(StringInfo buf, RangeTblEntry *rte, Index rtindex, Relation rel, List *targetAttrs, bool doNothing, List *withCheckOptionList, List *returningList, List **retrieved_attrs, int *values_end_len)
Definition: deparse.c:2081
deparseReturningList
static void deparseReturningList(StringInfo buf, RangeTblEntry *rte, Index rtindex, Relation rel, bool trig_after_row, List *withCheckOptionList, List *returningList, List **retrieved_attrs)
Definition: deparse.c:2440
deparseUpdateSql
void deparseUpdateSql(StringInfo buf, RangeTblEntry *rte, Index rtindex, Relation rel, List *targetAttrs, List *withCheckOptionList, List *returningList, List **retrieved_attrs)
Definition: deparse.c:2214
deparseVar
static void deparseVar(Var *node, deparse_expr_cxt *context)
Definition: deparse.c:2947
appendFunctionName
static void appendFunctionName(Oid funcid, deparse_expr_cxt *context)
Definition: deparse.c:4030
appendConditions
static void appendConditions(List *exprs, deparse_expr_cxt *context)
Definition: deparse.c:1569
foreign_loc_cxt
struct foreign_loc_cxt foreign_loc_cxt
deparseDeleteSql
void deparseDeleteSql(StringInfo buf, RangeTblEntry *rte, Index rtindex, Relation rel, List *returningList, List **retrieved_attrs)
Definition: deparse.c:2360
deparseAnalyzeSql
void deparseAnalyzeSql(StringInfo buf, Relation rel, PgFdwSamplingMethod sample_method, double sample_frac, List **retrieved_attrs)
Definition: deparse.c:2559
deparseSubscriptingRef
static void deparseSubscriptingRef(SubscriptingRef *node, deparse_expr_cxt *context)
Definition: deparse.c:3165
deparseRelation
static void deparseRelation(StringInfo buf, Relation rel)
Definition: deparse.c:2807
deparseExplicitTargetList
static void deparseExplicitTargetList(List *tlist, bool is_returning, List **retrieved_attrs, deparse_expr_cxt *context)
Definition: deparse.c:1679
deparse_type_name
static char * deparse_type_name(Oid type_oid, int32 typemod)
Definition: deparse.c:1155
ADD_REL_QUALIFIER
#define ADD_REL_QUALIFIER(buf, varno)
Definition: deparse.c:110
appendLimitClause
static void appendLimitClause(deparse_expr_cxt *context)
Definition: deparse.c:4002
deparseExpr
static void deparseExpr(Expr *node, deparse_expr_cxt *context)
Definition: deparse.c:2882
is_foreign_expr
bool is_foreign_expr(PlannerInfo *root, RelOptInfo *baserel, Expr *expr)
Definition: deparse.c:242
build_tlist_to_deparse
List * build_tlist_to_deparse(RelOptInfo *foreignrel)
Definition: deparse.c:1174
deparseFromExprForRel
static void deparseFromExprForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel, bool use_alias, Index ignore_rel, List **ignore_conds, List **additional_conds, List **params_list)
Definition: deparse.c:1759
SUBQUERY_COL_ALIAS_PREFIX
#define SUBQUERY_COL_ALIAS_PREFIX
Definition: deparse.c:113
classifyConditions
void classifyConditions(PlannerInfo *root, RelOptInfo *baserel, List *input_conds, List **remote_conds, List **local_conds)
Definition: deparse.c:216
deparseScalarArrayOpExpr
static void deparseScalarArrayOpExpr(ScalarArrayOpExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3450
appendWhereClause
static void appendWhereClause(List *exprs, List *additional_conds, deparse_expr_cxt *context)
Definition: deparse.c:1606
deparseTruncateSql
void deparseTruncateSql(StringInfo buf, List *rels, DropBehavior behavior, bool restart_seqs)
Definition: deparse.c:2644
deparseSubqueryTargetList
static void deparseSubqueryTargetList(deparse_expr_cxt *context)
Definition: deparse.c:1715
is_foreign_pathkey
bool is_foreign_pathkey(PlannerInfo *root, RelOptInfo *baserel, PathKey *pathkey)
Definition: deparse.c:1121
deparseSelectSql
static void deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_attrs, deparse_expr_cxt *context)
Definition: deparse.c:1313
deparseParam
static void deparseParam(Param *node, deparse_expr_cxt *context)
Definition: deparse.c:3132
appendAggOrderBy
static void appendAggOrderBy(List *orderList, List *targetList, deparse_expr_cxt *context)
Definition: deparse.c:3747
ERROR
#define ERROR
Definition: elog.h:39
elog
#define elog(elevel,...)
Definition: elog.h:225
equal
bool equal(const void *a, const void *b)
Definition: equalfuncs.c:223
OidOutputFunctionCall
char * OidOutputFunctionCall(Oid functionId, Datum val)
Definition: fmgr.c:1763
GetForeignTable
ForeignTable * GetForeignTable(Oid relid)
Definition: foreign.c:254
GetForeignColumnOptions
List * GetForeignColumnOptions(Oid relid, AttrNumber attnum)
Definition: foreign.c:292
format_type_extended
char * format_type_extended(Oid type_oid, int32 typemod, bits16 flags)
Definition: format_type.c:112
str
const char * str
Definition: hashfn_unstable.h:263
HeapTupleIsValid
#define HeapTupleIsValid(tuple)
Definition: htup.h:78
htup_details.h
GETSTRUCT
#define GETSTRUCT(TUP)
Definition: htup_details.h:653
val
long val
Definition: informix.c:689
b
int b
Definition: isn.c:69
a
int a
Definition: isn.c:68
i
int i
Definition: isn.c:72
if
if(TABLE==NULL||TABLE_index==NULL)
Definition: isn.c:76
lappend
List * lappend(List *list, void *datum)
Definition: list.c:339
lappend_int
List * lappend_int(List *list, int datum)
Definition: list.c:357
list_free
void list_free(List *list)
Definition: list.c:1546
list_concat
List * list_concat(List *list1, const List *list2)
Definition: list.c:561
list_free_deep
void list_free_deep(List *list)
Definition: list.c:1560
NoLock
#define NoLock
Definition: lockdefs.h:34
LCS_FORUPDATE
@ LCS_FORUPDATE
Definition: lockoptions.h:27
LCS_NONE
@ LCS_NONE
Definition: lockoptions.h:23
LCS_FORSHARE
@ LCS_FORSHARE
Definition: lockoptions.h:25
LCS_FORKEYSHARE
@ LCS_FORKEYSHARE
Definition: lockoptions.h:24
LCS_FORNOKEYUPDATE
@ LCS_FORNOKEYUPDATE
Definition: lockoptions.h:26
type_is_rowtype
bool type_is_rowtype(Oid typid)
Definition: lsyscache.c:2655
get_namespace_name
char * get_namespace_name(Oid nspid)
Definition: lsyscache.c:3366
getTypeOutputInfo
void getTypeOutputInfo(Oid type, Oid *typOutput, bool *typIsVarlena)
Definition: lsyscache.c:2907
get_opfamily_member
Oid get_opfamily_member(Oid opfamily, Oid lefttype, Oid righttype, int16 strategy)
Definition: lsyscache.c:166
get_attname
char * get_attname(Oid relid, AttrNumber attnum, bool missing_ok)
Definition: lsyscache.c:827
pfree
void pfree(void *pointer)
Definition: mcxt.c:1521
exprType
Oid exprType(const Node *expr)
Definition: nodeFuncs.c:42
exprIsLengthCoercion
bool exprIsLengthCoercion(const Node *expr, int32 *coercedTypmod)
Definition: nodeFuncs.c:552
strip_implicit_coercions
Node * strip_implicit_coercions(Node *node)
Definition: nodeFuncs.c:700
IsA
#define IsA(nodeptr, _type_)
Definition: nodes.h:158
nodeTag
#define nodeTag(nodeptr)
Definition: nodes.h:133
CMD_DELETE
@ CMD_DELETE
Definition: nodes.h:268
CMD_UPDATE
@ CMD_UPDATE
Definition: nodes.h:266
AGGSPLIT_SIMPLE
@ AGGSPLIT_SIMPLE
Definition: nodes.h:377
castNode
#define castNode(_type_, nodeptr)
Definition: nodes.h:176
JoinType
JoinType
Definition: nodes.h:288
JOIN_SEMI
@ JOIN_SEMI
Definition: nodes.h:307
JOIN_FULL
@ JOIN_FULL
Definition: nodes.h:295
JOIN_INNER
@ JOIN_INNER
Definition: nodes.h:293
JOIN_RIGHT
@ JOIN_RIGHT
Definition: nodes.h:296
JOIN_LEFT
@ JOIN_LEFT
Definition: nodes.h:294
PVC_RECURSE_PLACEHOLDERS
#define PVC_RECURSE_PLACEHOLDERS
Definition: optimizer.h:192
oprid
Oid oprid(Operator op)
Definition: parse_oper.c:238
DropBehavior
DropBehavior
Definition: parsenodes.h:2340
DROP_CASCADE
@ DROP_CASCADE
Definition: parsenodes.h:2342
DROP_RESTRICT
@ DROP_RESTRICT
Definition: parsenodes.h:2341
IS_SIMPLE_REL
#define IS_SIMPLE_REL(rel)
Definition: pathnodes.h:839
IS_JOIN_REL
#define IS_JOIN_REL(rel)
Definition: pathnodes.h:844
planner_rt_fetch
#define planner_rt_fetch(rti, root)
Definition: pathnodes.h:570
RELOPT_JOINREL
@ RELOPT_JOINREL
Definition: pathnodes.h:828
IS_UPPER_REL
#define IS_UPPER_REL(rel)
Definition: pathnodes.h:849
pg_aggregate.h
attname
NameData attname
Definition: pg_attribute.h:41
attnum
int16 attnum
Definition: pg_attribute.h:74
Form_pg_attribute
FormData_pg_attribute * Form_pg_attribute
Definition: pg_attribute.h:209
pg_authid.h
arg
void * arg
Definition: pg_backup_utils.c:29
relname
NameData relname
Definition: pg_class.h:38
pg_collation.h
while
while(p+4<=pend)
Definition: pg_crc32c_sse42.c:55
lfirst
#define lfirst(lc)
Definition: pg_list.h:172
llast
#define llast(l)
Definition: pg_list.h:198
lfirst_node
#define lfirst_node(type, lc)
Definition: pg_list.h:176
list_length
static int list_length(const List *l)
Definition: pg_list.h:152
NIL
#define NIL
Definition: pg_list.h:68
forboth
#define forboth(cell1, list1, cell2, list2)
Definition: pg_list.h:518
lfirst_int
#define lfirst_int(lc)
Definition: pg_list.h:173
list_head
static ListCell * list_head(const List *l)
Definition: pg_list.h:128
linitial
#define linitial(l)
Definition: pg_list.h:178
lsecond
#define lsecond(l)
Definition: pg_list.h:183
lnext
static ListCell * lnext(const List *l, const ListCell *c)
Definition: pg_list.h:343
pg_namespace.h
pg_operator.h
Form_pg_operator
FormData_pg_operator * Form_pg_operator
Definition: pg_operator.h:83
pg_opfamily.h
pg_proc.h
Form_pg_proc
FormData_pg_proc * Form_pg_proc
Definition: pg_proc.h:136
proname
NameData proname
Definition: pg_proc.h:35
options
static char ** options
Definition: pg_recvlogical.c:57
buf
static char * buf
Definition: pg_test_fsync.c:72
pg_ts_config.h
pg_ts_dict.h
pg_type.h
DatumGetObjectId
static Oid DatumGetObjectId(Datum X)
Definition: postgres.h:242
ObjectIdGetDatum
static Datum ObjectIdGetDatum(Oid X)
Definition: postgres.h:252
InvalidOid
#define InvalidOid
Definition: postgres_ext.h:36
Oid
unsigned int Oid
Definition: postgres_ext.h:31
reset_transmission_modes
void reset_transmission_modes(int nestlevel)
Definition: postgres_fdw.c:3943
set_transmission_modes
int set_transmission_modes(void)
Definition: postgres_fdw.c:3907
find_em_for_rel
EquivalenceMember * find_em_for_rel(PlannerInfo *root, EquivalenceClass *ec, RelOptInfo *rel)
Definition: postgres_fdw.c:7829
find_em_for_rel_target
EquivalenceMember * find_em_for_rel_target(PlannerInfo *root, EquivalenceClass *ec, RelOptInfo *rel)
Definition: postgres_fdw.c:7865
postgres_fdw.h
is_shippable
bool is_shippable(Oid objectId, Oid classId, PgFdwRelationInfo *fpinfo)
Definition: shippable.c:162
is_builtin
bool is_builtin(Oid objectId)
Definition: shippable.c:152
PgFdwSamplingMethod
PgFdwSamplingMethod
Definition: postgres_fdw.h:146
ANALYZE_SAMPLE_AUTO
@ ANALYZE_SAMPLE_AUTO
Definition: postgres_fdw.h:148
ANALYZE_SAMPLE_OFF
@ ANALYZE_SAMPLE_OFF
Definition: postgres_fdw.h:147
ANALYZE_SAMPLE_BERNOULLI
@ ANALYZE_SAMPLE_BERNOULLI
Definition: postgres_fdw.h:151
ANALYZE_SAMPLE_SYSTEM
@ ANALYZE_SAMPLE_SYSTEM
Definition: postgres_fdw.h:150
ANALYZE_SAMPLE_RANDOM
@ ANALYZE_SAMPLE_RANDOM
Definition: postgres_fdw.h:149
c
char * c
Definition: preproc-cursor.c:31
fe
static int fe(enum e x)
Definition: preproc-init.c:111
get_plan_rowmark
PlanRowMark * get_plan_rowmark(List *rowmarks, Index rtindex)
Definition: preptlist.c:509
AND_EXPR
@ AND_EXPR
Definition: primnodes.h:931
OR_EXPR
@ OR_EXPR
Definition: primnodes.h:931
NOT_EXPR
@ NOT_EXPR
Definition: primnodes.h:931
PARAM_MULTIEXPR
@ PARAM_MULTIEXPR
Definition: primnodes.h:370
IS_SPECIAL_VARNO
#define IS_SPECIAL_VARNO(varno)
Definition: primnodes.h:241
COERCE_IMPLICIT_CAST
@ COERCE_IMPLICIT_CAST
Definition: primnodes.h:736
COERCE_EXPLICIT_CAST
@ COERCE_EXPLICIT_CAST
Definition: primnodes.h:735
IS_NULL
@ IS_NULL
Definition: primnodes.h:1952
context
tree context
Definition: radixtree.h:1835
root
tree ctl root
Definition: radixtree.h:1886
RelationGetRelid
#define RelationGetRelid(relation)
Definition: rel.h:505
RelationGetDescr
#define RelationGetDescr(relation)
Definition: rel.h:531
RelationGetRelationName
#define RelationGetRelationName(relation)
Definition: rel.h:539
RelationGetNamespace
#define RelationGetNamespace(relation)
Definition: rel.h:546
quote_identifier
const char * quote_identifier(const char *ident)
Definition: ruleutils.c:12868
appendStringInfo
void appendStringInfo(StringInfo str, const char *fmt,...)
Definition: stringinfo.c:94
appendBinaryStringInfo
void appendBinaryStringInfo(StringInfo str, const void *data, int datalen)
Definition: stringinfo.c:230
appendStringInfoString
void appendStringInfoString(StringInfo str, const char *s)
Definition: stringinfo.c:179
appendStringInfoChar
void appendStringInfoChar(StringInfo str, char ch)
Definition: stringinfo.c:191
initStringInfo
void initStringInfo(StringInfo str)
Definition: stringinfo.c:56
Aggref::aggfnoid
Oid aggfnoid
Definition: primnodes.h:444
Aggref::aggdistinct
List * aggdistinct
Definition: primnodes.h:474
Aggref::aggdirectargs
List * aggdirectargs
Definition: primnodes.h:465
Aggref::args
List * args
Definition: primnodes.h:468
Aggref::aggfilter
Expr * aggfilter
Definition: primnodes.h:477
Aggref::aggorder
List * aggorder
Definition: primnodes.h:471
ArrayExpr::elements
List * elements
Definition: primnodes.h:1380
BoolExpr::boolop
BoolExprType boolop
Definition: primnodes.h:939
BoolExpr::args
List * args
Definition: primnodes.h:940
CaseExpr::arg
Expr * arg
Definition: primnodes.h:1313
CaseExpr::defresult
Expr * defresult
Definition: primnodes.h:1315
CaseExpr::args
List * args
Definition: primnodes.h:1314
CaseWhen::result
Expr * result
Definition: primnodes.h:1326
CaseWhen::expr
Expr * expr
Definition: primnodes.h:1325
Const::consttype
Oid consttype
Definition: primnodes.h:312
DefElem::defname
char * defname
Definition: parsenodes.h:817
ForeignTable::options
List * options
Definition: foreign.h:57
FuncExpr::funcid
Oid funcid
Definition: primnodes.h:750
FuncExpr::args
List * args
Definition: primnodes.h:768
List
Definition: pg_list.h:54
Node
Definition: nodes.h:129
NullTest::nulltesttype
NullTestType nulltesttype
Definition: primnodes.h:1959
NullTest::arg
Expr * arg
Definition: primnodes.h:1958
OpExpr::opno
Oid opno
Definition: primnodes.h:818
OpExpr::args
List * args
Definition: primnodes.h:836
Param::paramtype
Oid paramtype
Definition: primnodes.h:378
Param::paramkind
ParamKind paramkind
Definition: primnodes.h:376
PathKey::pk_nulls_first
bool pk_nulls_first
Definition: pathnodes.h:1480
PathKey::pk_strategy
int pk_strategy
Definition: pathnodes.h:1479
PathKey::pk_opfamily
Oid pk_opfamily
Definition: pathnodes.h:1478
PathTarget::exprs
List * exprs
Definition: pathnodes.h:1542
PgFdwRelationInfo::lower_subquery_rels
Relids lower_subquery_rels
Definition: postgres_fdw.h:120
PgFdwRelationInfo::outerrel
RelOptInfo * outerrel
Definition: postgres_fdw.h:103
PgFdwRelationInfo::attrs_used
Bitmapset * attrs_used
Definition: postgres_fdw.h:50
PgFdwRelationInfo::innerrel
RelOptInfo * innerrel
Definition: postgres_fdw.h:104
PlanRowMark::strength
LockClauseStrength strength
Definition: plannodes.h:1388
Query::groupClause
List * groupClause
Definition: parsenodes.h:202
Query::groupingSets
List * groupingSets
Definition: parsenodes.h:205
RelOptInfo::relids
Relids relids
Definition: pathnodes.h:871
RelOptInfo::reltarget
struct PathTarget * reltarget
Definition: pathnodes.h:893
RelOptInfo::relid
Index relid
Definition: pathnodes.h:918
RelOptInfo::reloptkind
RelOptKind reloptkind
Definition: pathnodes.h:865
RelabelType::resulttype
Oid resulttype
Definition: primnodes.h:1185
RelabelType::arg
Expr * arg
Definition: primnodes.h:1184
RelationData::trigdesc
TriggerDesc * trigdesc
Definition: rel.h:117
RestrictInfo::clause
Expr * clause
Definition: pathnodes.h:2574
SortGroupClause::tleSortGroupRef
Index tleSortGroupRef
Definition: parsenodes.h:1438
SubscriptingRef::refassgnexpr
Expr * refassgnexpr
Definition: primnodes.h:703
SubscriptingRef::refupperindexpr
List * refupperindexpr
Definition: primnodes.h:693
SubscriptingRef::refexpr
Expr * refexpr
Definition: primnodes.h:701
SubscriptingRef::reflowerindexpr
List * reflowerindexpr
Definition: primnodes.h:699
TargetEntry::expr
Expr * expr
Definition: primnodes.h:2190
TargetEntry::resno
AttrNumber resno
Definition: primnodes.h:2192
TriggerDesc::trig_update_after_row
bool trig_update_after_row
Definition: reltrigger.h:62
TriggerDesc::trig_insert_after_row
bool trig_insert_after_row
Definition: reltrigger.h:57
TriggerDesc::trig_delete_after_row
bool trig_delete_after_row
Definition: reltrigger.h:67
Var
Definition: primnodes.h:248
Var::varattno
AttrNumber varattno
Definition: primnodes.h:260
Var::varno
int varno
Definition: primnodes.h:255
Var::varlevelsup
Index varlevelsup
Definition: primnodes.h:280
deparse_expr_cxt
Definition: deparse.c:98
deparse_expr_cxt::root
PlannerInfo * root
Definition: deparse.c:99
deparse_expr_cxt::params_list
List ** params_list
Definition: deparse.c:105
deparse_expr_cxt::foreignrel
RelOptInfo * foreignrel
Definition: deparse.c:100
deparse_expr_cxt::buf
StringInfo buf
Definition: deparse.c:104
deparse_expr_cxt::scanrel
RelOptInfo * scanrel
Definition: deparse.c:101
foreign_glob_cxt
Definition: deparse.c:67
foreign_glob_cxt::foreignrel
RelOptInfo * foreignrel
Definition: deparse.c:69
foreign_glob_cxt::relids
Relids relids
Definition: deparse.c:70
foreign_glob_cxt::root
PlannerInfo * root
Definition: deparse.c:68
foreign_loc_cxt
Definition: deparse.c:89
foreign_loc_cxt::collation
Oid collation
Definition: deparse.c:90
foreign_loc_cxt::state
FDWCollateState state
Definition: deparse.c:91
nameData::data
char data[NAMEDATALEN]
Definition: c.h:696
state
Definition: regguts.h:323
FirstLowInvalidHeapAttributeNumber
#define FirstLowInvalidHeapAttributeNumber
Definition: sysattr.h:27
TableOidAttributeNumber
#define TableOidAttributeNumber
Definition: sysattr.h:26
SelfItemPointerAttributeNumber
#define SelfItemPointerAttributeNumber
Definition: sysattr.h:21
ReleaseSysCache
void ReleaseSysCache(HeapTuple tuple)
Definition: syscache.c:269
SearchSysCache1
HeapTuple SearchSysCache1(int cacheId, Datum key1)
Definition: syscache.c:221
table_close
void table_close(Relation relation, LOCKMODE lockmode)
Definition: table.c:126
table_open
Relation table_open(Oid relationId, LOCKMODE lockmode)
Definition: table.c:40
get_sortgroupref_tle
TargetEntry * get_sortgroupref_tle(Index sortref, List *targetList)
Definition: tlist.c:345
add_to_flat_tlist
List * add_to_flat_tlist(List *tlist, List *exprs)
Definition: tlist.c:132
FirstNormalObjectId
#define FirstNormalObjectId
Definition: transam.h:197
TupleDescAttr
#define TupleDescAttr(tupdesc, i)
Definition: tupdesc.h:92
lookup_type_cache
TypeCacheEntry * lookup_type_cache(Oid type_id, int flags)
Definition: typcache.c:386
TYPECACHE_GT_OPR
#define TYPECACHE_GT_OPR
Definition: typcache.h:139
TYPECACHE_LT_OPR
#define TYPECACHE_LT_OPR
Definition: typcache.h:138
pull_var_clause
List * pull_var_clause(Node *node, int flags)
Definition: var.c:609
pull_varattnos
void pull_varattnos(Node *node, Index varno, Bitmapset **varattnos)
Definition: var.c:295