PostgreSQL Source Code  git master
deparse.c
Go to the documentation of this file.
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) 2012-2022, 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/makefuncs.h"
51 #include "nodes/nodeFuncs.h"
52 #include "nodes/plannodes.h"
53 #include "optimizer/optimizer.h"
54 #include "optimizer/prep.h"
55 #include "optimizer/tlist.h"
56 #include "parser/parsetree.h"
57 #include "postgres_fdw.h"
58 #include "utils/builtins.h"
59 #include "utils/lsyscache.h"
60 #include "utils/rel.h"
61 #include "utils/syscache.h"
62 #include "utils/typcache.h"
63 #include "commands/tablecmds.h"
64 
65 /*
66  * Global context for foreign_expr_walker's search of an expression tree.
67  */
68 typedef struct foreign_glob_cxt
69 {
70  PlannerInfo *root; /* global planner state */
71  RelOptInfo *foreignrel; /* the foreign relation we are planning for */
72  Relids relids; /* relids of base relations in the underlying
73  * scan */
75 
76 /*
77  * Local (per-tree-level) context for foreign_expr_walker's search.
78  * This is concerned with identifying collations used in the expression.
79  */
80 typedef enum
81 {
82  FDW_COLLATE_NONE, /* expression is of a noncollatable type, or
83  * it has default collation that is not
84  * traceable to a foreign Var */
85  FDW_COLLATE_SAFE, /* collation derives from a foreign Var */
86  FDW_COLLATE_UNSAFE /* collation is non-default and derives from
87  * something other than a foreign Var */
89 
90 typedef struct foreign_loc_cxt
91 {
92  Oid collation; /* OID of current collation, if any */
93  FDWCollateState state; /* state of current collation choice */
95 
96 /*
97  * Context for deparseExpr
98  */
99 typedef struct deparse_expr_cxt
100 {
101  PlannerInfo *root; /* global planner state */
102  RelOptInfo *foreignrel; /* the foreign relation we are planning for */
103  RelOptInfo *scanrel; /* the underlying scan relation. Same as
104  * foreignrel, when that represents a join or
105  * a base relation. */
106  StringInfo buf; /* output buffer to append to */
107  List **params_list; /* exprs that will become remote Params */
109 
110 #define REL_ALIAS_PREFIX "r"
111 /* Handy macro to add relation name qualification */
112 #define ADD_REL_QUALIFIER(buf, varno) \
113  appendStringInfo((buf), "%s%d.", REL_ALIAS_PREFIX, (varno))
114 #define SUBQUERY_REL_ALIAS_PREFIX "s"
115 #define SUBQUERY_COL_ALIAS_PREFIX "c"
116 
117 /*
118  * Functions to determine whether an expression can be evaluated safely on
119  * remote server.
120  */
121 static bool foreign_expr_walker(Node *node,
122  foreign_glob_cxt *glob_cxt,
123  foreign_loc_cxt *outer_cxt,
124  foreign_loc_cxt *case_arg_cxt);
125 static char *deparse_type_name(Oid type_oid, int32 typemod);
126 
127 /*
128  * Functions to construct string representation of a node tree.
129  */
130 static void deparseTargetList(StringInfo buf,
131  RangeTblEntry *rte,
132  Index rtindex,
133  Relation rel,
134  bool is_returning,
135  Bitmapset *attrs_used,
136  bool qualify_col,
137  List **retrieved_attrs);
138 static void deparseExplicitTargetList(List *tlist,
139  bool is_returning,
140  List **retrieved_attrs,
141  deparse_expr_cxt *context);
142 static void deparseSubqueryTargetList(deparse_expr_cxt *context);
144  Index rtindex, Relation rel,
145  bool trig_after_row,
146  List *withCheckOptionList,
147  List *returningList,
148  List **retrieved_attrs);
149 static void deparseColumnRef(StringInfo buf, int varno, int varattno,
150  RangeTblEntry *rte, bool qualify_col);
151 static void deparseRelation(StringInfo buf, Relation rel);
152 static void deparseExpr(Expr *node, deparse_expr_cxt *context);
153 static void deparseVar(Var *node, deparse_expr_cxt *context);
154 static void deparseConst(Const *node, deparse_expr_cxt *context, int showtype);
155 static void deparseParam(Param *node, deparse_expr_cxt *context);
156 static void deparseSubscriptingRef(SubscriptingRef *node, deparse_expr_cxt *context);
157 static void deparseFuncExpr(FuncExpr *node, deparse_expr_cxt *context);
158 static void deparseOpExpr(OpExpr *node, deparse_expr_cxt *context);
159 static bool isPlainForeignVar(Expr *node, deparse_expr_cxt *context);
161 static void deparseDistinctExpr(DistinctExpr *node, deparse_expr_cxt *context);
163  deparse_expr_cxt *context);
164 static void deparseRelabelType(RelabelType *node, deparse_expr_cxt *context);
165 static void deparseBoolExpr(BoolExpr *node, deparse_expr_cxt *context);
166 static void deparseNullTest(NullTest *node, deparse_expr_cxt *context);
167 static void deparseCaseExpr(CaseExpr *node, deparse_expr_cxt *context);
168 static void deparseArrayExpr(ArrayExpr *node, deparse_expr_cxt *context);
169 static void printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod,
170  deparse_expr_cxt *context);
171 static void printRemotePlaceholder(Oid paramtype, int32 paramtypmod,
172  deparse_expr_cxt *context);
173 static void deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_attrs,
174  deparse_expr_cxt *context);
175 static void deparseLockingClause(deparse_expr_cxt *context);
176 static void appendOrderByClause(List *pathkeys, bool has_final_sort,
177  deparse_expr_cxt *context);
178 static void appendLimitClause(deparse_expr_cxt *context);
179 static void appendConditions(List *exprs, deparse_expr_cxt *context);
181  RelOptInfo *foreignrel, bool use_alias,
182  Index ignore_rel, List **ignore_conds,
183  List **params_list);
184 static void deparseFromExpr(List *quals, deparse_expr_cxt *context);
185 static void deparseRangeTblRef(StringInfo buf, PlannerInfo *root,
186  RelOptInfo *foreignrel, bool make_subquery,
187  Index ignore_rel, List **ignore_conds, List **params_list);
188 static void deparseAggref(Aggref *node, deparse_expr_cxt *context);
189 static void appendGroupByClause(List *tlist, deparse_expr_cxt *context);
190 static void appendOrderBySuffix(Oid sortop, Oid sortcoltype, bool nulls_first,
191  deparse_expr_cxt *context);
192 static void appendAggOrderBy(List *orderList, List *targetList,
193  deparse_expr_cxt *context);
194 static void appendFunctionName(Oid funcid, deparse_expr_cxt *context);
195 static Node *deparseSortGroupClause(Index ref, List *tlist, bool force_colno,
196  deparse_expr_cxt *context);
197 
198 /*
199  * Helper functions
200  */
201 static bool is_subquery_var(Var *node, RelOptInfo *foreignrel,
202  int *relno, int *colno);
203 static void get_relation_column_alias_ids(Var *node, RelOptInfo *foreignrel,
204  int *relno, int *colno);
205 
206 
207 /*
208  * Examine each qual clause in input_conds, and classify them into two groups,
209  * which are returned as two lists:
210  * - remote_conds contains expressions that can be evaluated remotely
211  * - local_conds contains expressions that can't be evaluated remotely
212  */
213 void
215  RelOptInfo *baserel,
216  List *input_conds,
217  List **remote_conds,
218  List **local_conds)
219 {
220  ListCell *lc;
221 
222  *remote_conds = NIL;
223  *local_conds = NIL;
224 
225  foreach(lc, input_conds)
226  {
228 
229  if (is_foreign_expr(root, baserel, ri->clause))
230  *remote_conds = lappend(*remote_conds, ri);
231  else
232  *local_conds = lappend(*local_conds, ri);
233  }
234 }
235 
236 /*
237  * Returns true if given expr is safe to evaluate on the foreign server.
238  */
239 bool
241  RelOptInfo *baserel,
242  Expr *expr)
243 {
244  foreign_glob_cxt glob_cxt;
245  foreign_loc_cxt loc_cxt;
246  PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) (baserel->fdw_private);
247 
248  /*
249  * Check that the expression consists of nodes that are safe to execute
250  * remotely.
251  */
252  glob_cxt.root = root;
253  glob_cxt.foreignrel = baserel;
254 
255  /*
256  * For an upper relation, use relids from its underneath scan relation,
257  * because the upperrel's own relids currently aren't set to anything
258  * meaningful by the core code. For other relation, use their own relids.
259  */
260  if (IS_UPPER_REL(baserel))
261  glob_cxt.relids = fpinfo->outerrel->relids;
262  else
263  glob_cxt.relids = baserel->relids;
264  loc_cxt.collation = InvalidOid;
265  loc_cxt.state = FDW_COLLATE_NONE;
266  if (!foreign_expr_walker((Node *) expr, &glob_cxt, &loc_cxt, NULL))
267  return false;
268 
269  /*
270  * If the expression has a valid collation that does not arise from a
271  * foreign var, the expression can not be sent over.
272  */
273  if (loc_cxt.state == FDW_COLLATE_UNSAFE)
274  return false;
275 
276  /*
277  * An expression which includes any mutable functions can't be sent over
278  * because its result is not stable. For example, sending now() remote
279  * side could cause confusion from clock offsets. Future versions might
280  * be able to make this choice with more granularity. (We check this last
281  * because it requires a lot of expensive catalog lookups.)
282  */
283  if (contain_mutable_functions((Node *) expr))
284  return false;
285 
286  /* OK to evaluate on the remote server */
287  return true;
288 }
289 
290 /*
291  * Check if expression is safe to execute remotely, and return true if so.
292  *
293  * In addition, *outer_cxt is updated with collation information.
294  *
295  * case_arg_cxt is NULL if this subexpression is not inside a CASE-with-arg.
296  * Otherwise, it points to the collation info derived from the arg expression,
297  * which must be consulted by any CaseTestExpr.
298  *
299  * We must check that the expression contains only node types we can deparse,
300  * that all types/functions/operators are safe to send (they are "shippable"),
301  * and that all collations used in the expression derive from Vars of the
302  * foreign table. Because of the latter, the logic is pretty close to
303  * assign_collations_walker() in parse_collate.c, though we can assume here
304  * that the given expression is valid. Note function mutability is not
305  * currently considered here.
306  */
307 static bool
309  foreign_glob_cxt *glob_cxt,
310  foreign_loc_cxt *outer_cxt,
311  foreign_loc_cxt *case_arg_cxt)
312 {
313  bool check_type = true;
314  PgFdwRelationInfo *fpinfo;
315  foreign_loc_cxt inner_cxt;
316  Oid collation;
318 
319  /* Need do nothing for empty subexpressions */
320  if (node == NULL)
321  return true;
322 
323  /* May need server info from baserel's fdw_private struct */
324  fpinfo = (PgFdwRelationInfo *) (glob_cxt->foreignrel->fdw_private);
325 
326  /* Set up inner_cxt for possible recursion to child nodes */
327  inner_cxt.collation = InvalidOid;
328  inner_cxt.state = FDW_COLLATE_NONE;
329 
330  switch (nodeTag(node))
331  {
332  case T_Var:
333  {
334  Var *var = (Var *) node;
335 
336  /*
337  * If the Var is from the foreign table, we consider its
338  * collation (if any) safe to use. If it is from another
339  * table, we treat its collation the same way as we would a
340  * Param's collation, ie it's not safe for it to have a
341  * non-default collation.
342  */
343  if (bms_is_member(var->varno, glob_cxt->relids) &&
344  var->varlevelsup == 0)
345  {
346  /* Var belongs to foreign table */
347 
348  /*
349  * System columns other than ctid should not be sent to
350  * the remote, since we don't make any effort to ensure
351  * that local and remote values match (tableoid, in
352  * particular, almost certainly doesn't match).
353  */
354  if (var->varattno < 0 &&
356  return false;
357 
358  /* Else check the collation */
359  collation = var->varcollid;
361  }
362  else
363  {
364  /* Var belongs to some other table */
365  collation = var->varcollid;
366  if (collation == InvalidOid ||
367  collation == DEFAULT_COLLATION_OID)
368  {
369  /*
370  * It's noncollatable, or it's safe to combine with a
371  * collatable foreign Var, so set state to NONE.
372  */
374  }
375  else
376  {
377  /*
378  * Do not fail right away, since the Var might appear
379  * in a collation-insensitive context.
380  */
382  }
383  }
384  }
385  break;
386  case T_Const:
387  {
388  Const *c = (Const *) node;
389 
390  /*
391  * Constants of regproc and related types can't be shipped
392  * unless the referenced object is shippable. But NULL's ok.
393  * (See also the related code in dependency.c.)
394  */
395  if (!c->constisnull)
396  {
397  switch (c->consttype)
398  {
399  case REGPROCOID:
400  case REGPROCEDUREOID:
401  if (!is_shippable(DatumGetObjectId(c->constvalue),
402  ProcedureRelationId, fpinfo))
403  return false;
404  break;
405  case REGOPEROID:
406  case REGOPERATOROID:
407  if (!is_shippable(DatumGetObjectId(c->constvalue),
408  OperatorRelationId, fpinfo))
409  return false;
410  break;
411  case REGCLASSOID:
412  if (!is_shippable(DatumGetObjectId(c->constvalue),
413  RelationRelationId, fpinfo))
414  return false;
415  break;
416  case REGTYPEOID:
417  if (!is_shippable(DatumGetObjectId(c->constvalue),
418  TypeRelationId, fpinfo))
419  return false;
420  break;
421  case REGCOLLATIONOID:
422  if (!is_shippable(DatumGetObjectId(c->constvalue),
423  CollationRelationId, fpinfo))
424  return false;
425  break;
426  case REGCONFIGOID:
427 
428  /*
429  * For text search objects only, we weaken the
430  * normal shippability criterion to allow all OIDs
431  * below FirstNormalObjectId. Without this, none
432  * of the initdb-installed TS configurations would
433  * be shippable, which would be quite annoying.
434  */
435  if (DatumGetObjectId(c->constvalue) >= FirstNormalObjectId &&
436  !is_shippable(DatumGetObjectId(c->constvalue),
437  TSConfigRelationId, fpinfo))
438  return false;
439  break;
440  case REGDICTIONARYOID:
441  if (DatumGetObjectId(c->constvalue) >= FirstNormalObjectId &&
442  !is_shippable(DatumGetObjectId(c->constvalue),
443  TSDictionaryRelationId, fpinfo))
444  return false;
445  break;
446  case REGNAMESPACEOID:
447  if (!is_shippable(DatumGetObjectId(c->constvalue),
448  NamespaceRelationId, fpinfo))
449  return false;
450  break;
451  case REGROLEOID:
452  if (!is_shippable(DatumGetObjectId(c->constvalue),
453  AuthIdRelationId, fpinfo))
454  return false;
455  break;
456  }
457  }
458 
459  /*
460  * If the constant has nondefault collation, either it's of a
461  * non-builtin type, or it reflects folding of a CollateExpr.
462  * It's unsafe to send to the remote unless it's used in a
463  * non-collation-sensitive context.
464  */
465  collation = c->constcollid;
466  if (collation == InvalidOid ||
467  collation == DEFAULT_COLLATION_OID)
469  else
471  }
472  break;
473  case T_Param:
474  {
475  Param *p = (Param *) node;
476 
477  /*
478  * If it's a MULTIEXPR Param, punt. We can't tell from here
479  * whether the referenced sublink/subplan contains any remote
480  * Vars; if it does, handling that is too complicated to
481  * consider supporting at present. Fortunately, MULTIEXPR
482  * Params are not reduced to plain PARAM_EXEC until the end of
483  * planning, so we can easily detect this case. (Normal
484  * PARAM_EXEC Params are safe to ship because their values
485  * come from somewhere else in the plan tree; but a MULTIEXPR
486  * references a sub-select elsewhere in the same targetlist,
487  * so we'd be on the hook to evaluate it somehow if we wanted
488  * to handle such cases as direct foreign updates.)
489  */
490  if (p->paramkind == PARAM_MULTIEXPR)
491  return false;
492 
493  /*
494  * Collation rule is same as for Consts and non-foreign Vars.
495  */
496  collation = p->paramcollid;
497  if (collation == InvalidOid ||
498  collation == DEFAULT_COLLATION_OID)
500  else
502  }
503  break;
504  case T_SubscriptingRef:
505  {
506  SubscriptingRef *sr = (SubscriptingRef *) node;
507 
508  /* Assignment should not be in restrictions. */
509  if (sr->refassgnexpr != NULL)
510  return false;
511 
512  /*
513  * Recurse into the remaining subexpressions. The container
514  * subscripts will not affect collation of the SubscriptingRef
515  * result, so do those first and reset inner_cxt afterwards.
516  */
518  glob_cxt, &inner_cxt, case_arg_cxt))
519  return false;
520  inner_cxt.collation = InvalidOid;
521  inner_cxt.state = FDW_COLLATE_NONE;
523  glob_cxt, &inner_cxt, case_arg_cxt))
524  return false;
525  inner_cxt.collation = InvalidOid;
526  inner_cxt.state = FDW_COLLATE_NONE;
527  if (!foreign_expr_walker((Node *) sr->refexpr,
528  glob_cxt, &inner_cxt, case_arg_cxt))
529  return false;
530 
531  /*
532  * Container subscripting typically yields same collation as
533  * refexpr's, but in case it doesn't, use same logic as for
534  * function nodes.
535  */
536  collation = sr->refcollid;
537  if (collation == InvalidOid)
539  else if (inner_cxt.state == FDW_COLLATE_SAFE &&
540  collation == inner_cxt.collation)
542  else if (collation == DEFAULT_COLLATION_OID)
544  else
546  }
547  break;
548  case T_FuncExpr:
549  {
550  FuncExpr *fe = (FuncExpr *) node;
551 
552  /*
553  * If function used by the expression is not shippable, it
554  * can't be sent to remote because it might have incompatible
555  * semantics on remote side.
556  */
557  if (!is_shippable(fe->funcid, ProcedureRelationId, fpinfo))
558  return false;
559 
560  /*
561  * Recurse to input subexpressions.
562  */
563  if (!foreign_expr_walker((Node *) fe->args,
564  glob_cxt, &inner_cxt, case_arg_cxt))
565  return false;
566 
567  /*
568  * If function's input collation is not derived from a foreign
569  * Var, it can't be sent to remote.
570  */
571  if (fe->inputcollid == InvalidOid)
572  /* OK, inputs are all noncollatable */ ;
573  else if (inner_cxt.state != FDW_COLLATE_SAFE ||
574  fe->inputcollid != inner_cxt.collation)
575  return false;
576 
577  /*
578  * Detect whether node is introducing a collation not derived
579  * from a foreign Var. (If so, we just mark it unsafe for now
580  * rather than immediately returning false, since the parent
581  * node might not care.)
582  */
583  collation = fe->funccollid;
584  if (collation == InvalidOid)
586  else if (inner_cxt.state == FDW_COLLATE_SAFE &&
587  collation == inner_cxt.collation)
589  else if (collation == DEFAULT_COLLATION_OID)
591  else
593  }
594  break;
595  case T_OpExpr:
596  case T_DistinctExpr: /* struct-equivalent to OpExpr */
597  {
598  OpExpr *oe = (OpExpr *) node;
599 
600  /*
601  * Similarly, only shippable operators can be sent to remote.
602  * (If the operator is shippable, we assume its underlying
603  * function is too.)
604  */
605  if (!is_shippable(oe->opno, OperatorRelationId, fpinfo))
606  return false;
607 
608  /*
609  * Recurse to input subexpressions.
610  */
611  if (!foreign_expr_walker((Node *) oe->args,
612  glob_cxt, &inner_cxt, case_arg_cxt))
613  return false;
614 
615  /*
616  * If operator's input collation is not derived from a foreign
617  * Var, it can't be sent to remote.
618  */
619  if (oe->inputcollid == InvalidOid)
620  /* OK, inputs are all noncollatable */ ;
621  else if (inner_cxt.state != FDW_COLLATE_SAFE ||
622  oe->inputcollid != inner_cxt.collation)
623  return false;
624 
625  /* Result-collation handling is same as for functions */
626  collation = oe->opcollid;
627  if (collation == InvalidOid)
629  else if (inner_cxt.state == FDW_COLLATE_SAFE &&
630  collation == inner_cxt.collation)
632  else if (collation == DEFAULT_COLLATION_OID)
634  else
636  }
637  break;
638  case T_ScalarArrayOpExpr:
639  {
640  ScalarArrayOpExpr *oe = (ScalarArrayOpExpr *) node;
641 
642  /*
643  * Again, only shippable operators can be sent to remote.
644  */
645  if (!is_shippable(oe->opno, OperatorRelationId, fpinfo))
646  return false;
647 
648  /*
649  * Recurse to input subexpressions.
650  */
651  if (!foreign_expr_walker((Node *) oe->args,
652  glob_cxt, &inner_cxt, case_arg_cxt))
653  return false;
654 
655  /*
656  * If operator's input collation is not derived from a foreign
657  * Var, it can't be sent to remote.
658  */
659  if (oe->inputcollid == InvalidOid)
660  /* OK, inputs are all noncollatable */ ;
661  else if (inner_cxt.state != FDW_COLLATE_SAFE ||
662  oe->inputcollid != inner_cxt.collation)
663  return false;
664 
665  /* Output is always boolean and so noncollatable. */
666  collation = InvalidOid;
668  }
669  break;
670  case T_RelabelType:
671  {
672  RelabelType *r = (RelabelType *) node;
673 
674  /*
675  * Recurse to input subexpression.
676  */
677  if (!foreign_expr_walker((Node *) r->arg,
678  glob_cxt, &inner_cxt, case_arg_cxt))
679  return false;
680 
681  /*
682  * RelabelType must not introduce a collation not derived from
683  * an input foreign Var (same logic as for a real function).
684  */
685  collation = r->resultcollid;
686  if (collation == InvalidOid)
688  else if (inner_cxt.state == FDW_COLLATE_SAFE &&
689  collation == inner_cxt.collation)
691  else if (collation == DEFAULT_COLLATION_OID)
693  else
695  }
696  break;
697  case T_BoolExpr:
698  {
699  BoolExpr *b = (BoolExpr *) node;
700 
701  /*
702  * Recurse to input subexpressions.
703  */
704  if (!foreign_expr_walker((Node *) b->args,
705  glob_cxt, &inner_cxt, case_arg_cxt))
706  return false;
707 
708  /* Output is always boolean and so noncollatable. */
709  collation = InvalidOid;
711  }
712  break;
713  case T_NullTest:
714  {
715  NullTest *nt = (NullTest *) node;
716 
717  /*
718  * Recurse to input subexpressions.
719  */
720  if (!foreign_expr_walker((Node *) nt->arg,
721  glob_cxt, &inner_cxt, case_arg_cxt))
722  return false;
723 
724  /* Output is always boolean and so noncollatable. */
725  collation = InvalidOid;
727  }
728  break;
729  case T_CaseExpr:
730  {
731  CaseExpr *ce = (CaseExpr *) node;
732  foreign_loc_cxt arg_cxt;
733  foreign_loc_cxt tmp_cxt;
734  ListCell *lc;
735 
736  /*
737  * Recurse to CASE's arg expression, if any. Its collation
738  * has to be saved aside for use while examining CaseTestExprs
739  * within the WHEN expressions.
740  */
741  arg_cxt.collation = InvalidOid;
742  arg_cxt.state = FDW_COLLATE_NONE;
743  if (ce->arg)
744  {
745  if (!foreign_expr_walker((Node *) ce->arg,
746  glob_cxt, &arg_cxt, case_arg_cxt))
747  return false;
748  }
749 
750  /* Examine the CaseWhen subexpressions. */
751  foreach(lc, ce->args)
752  {
753  CaseWhen *cw = lfirst_node(CaseWhen, lc);
754 
755  if (ce->arg)
756  {
757  /*
758  * In a CASE-with-arg, the parser should have produced
759  * WHEN clauses of the form "CaseTestExpr = RHS",
760  * possibly with an implicit coercion inserted above
761  * the CaseTestExpr. However in an expression that's
762  * been through the optimizer, the WHEN clause could
763  * be almost anything (since the equality operator
764  * could have been expanded into an inline function).
765  * In such cases forbid pushdown, because
766  * deparseCaseExpr can't handle it.
767  */
768  Node *whenExpr = (Node *) cw->expr;
769  List *opArgs;
770 
771  if (!IsA(whenExpr, OpExpr))
772  return false;
773 
774  opArgs = ((OpExpr *) whenExpr)->args;
775  if (list_length(opArgs) != 2 ||
777  CaseTestExpr))
778  return false;
779  }
780 
781  /*
782  * Recurse to WHEN expression, passing down the arg info.
783  * Its collation doesn't affect the result (really, it
784  * should be boolean and thus not have a collation).
785  */
786  tmp_cxt.collation = InvalidOid;
787  tmp_cxt.state = FDW_COLLATE_NONE;
788  if (!foreign_expr_walker((Node *) cw->expr,
789  glob_cxt, &tmp_cxt, &arg_cxt))
790  return false;
791 
792  /* Recurse to THEN expression. */
793  if (!foreign_expr_walker((Node *) cw->result,
794  glob_cxt, &inner_cxt, case_arg_cxt))
795  return false;
796  }
797 
798  /* Recurse to ELSE expression. */
799  if (!foreign_expr_walker((Node *) ce->defresult,
800  glob_cxt, &inner_cxt, case_arg_cxt))
801  return false;
802 
803  /*
804  * Detect whether node is introducing a collation not derived
805  * from a foreign Var. (If so, we just mark it unsafe for now
806  * rather than immediately returning false, since the parent
807  * node might not care.) This is the same as for function
808  * nodes, except that the input collation is derived from only
809  * the THEN and ELSE subexpressions.
810  */
811  collation = ce->casecollid;
812  if (collation == InvalidOid)
814  else if (inner_cxt.state == FDW_COLLATE_SAFE &&
815  collation == inner_cxt.collation)
817  else if (collation == DEFAULT_COLLATION_OID)
819  else
821  }
822  break;
823  case T_CaseTestExpr:
824  {
825  CaseTestExpr *c = (CaseTestExpr *) node;
826 
827  /* Punt if we seem not to be inside a CASE arg WHEN. */
828  if (!case_arg_cxt)
829  return false;
830 
831  /*
832  * Otherwise, any nondefault collation attached to the
833  * CaseTestExpr node must be derived from foreign Var(s) in
834  * the CASE arg.
835  */
836  collation = c->collation;
837  if (collation == InvalidOid)
839  else if (case_arg_cxt->state == FDW_COLLATE_SAFE &&
840  collation == case_arg_cxt->collation)
842  else if (collation == DEFAULT_COLLATION_OID)
844  else
846  }
847  break;
848  case T_ArrayExpr:
849  {
850  ArrayExpr *a = (ArrayExpr *) node;
851 
852  /*
853  * Recurse to input subexpressions.
854  */
855  if (!foreign_expr_walker((Node *) a->elements,
856  glob_cxt, &inner_cxt, case_arg_cxt))
857  return false;
858 
859  /*
860  * ArrayExpr must not introduce a collation not derived from
861  * an input foreign Var (same logic as for a function).
862  */
863  collation = a->array_collid;
864  if (collation == InvalidOid)
866  else if (inner_cxt.state == FDW_COLLATE_SAFE &&
867  collation == inner_cxt.collation)
869  else if (collation == DEFAULT_COLLATION_OID)
871  else
873  }
874  break;
875  case T_List:
876  {
877  List *l = (List *) node;
878  ListCell *lc;
879 
880  /*
881  * Recurse to component subexpressions.
882  */
883  foreach(lc, l)
884  {
885  if (!foreign_expr_walker((Node *) lfirst(lc),
886  glob_cxt, &inner_cxt, case_arg_cxt))
887  return false;
888  }
889 
890  /*
891  * When processing a list, collation state just bubbles up
892  * from the list elements.
893  */
894  collation = inner_cxt.collation;
895  state = inner_cxt.state;
896 
897  /* Don't apply exprType() to the list. */
898  check_type = false;
899  }
900  break;
901  case T_Aggref:
902  {
903  Aggref *agg = (Aggref *) node;
904  ListCell *lc;
905 
906  /* Not safe to pushdown when not in grouping context */
907  if (!IS_UPPER_REL(glob_cxt->foreignrel))
908  return false;
909 
910  /* Only non-split aggregates are pushable. */
911  if (agg->aggsplit != AGGSPLIT_SIMPLE)
912  return false;
913 
914  /* As usual, it must be shippable. */
915  if (!is_shippable(agg->aggfnoid, ProcedureRelationId, fpinfo))
916  return false;
917 
918  /*
919  * Recurse to input args. aggdirectargs, aggorder and
920  * aggdistinct are all present in args, so no need to check
921  * their shippability explicitly.
922  */
923  foreach(lc, agg->args)
924  {
925  Node *n = (Node *) lfirst(lc);
926 
927  /* If TargetEntry, extract the expression from it */
928  if (IsA(n, TargetEntry))
929  {
930  TargetEntry *tle = (TargetEntry *) n;
931 
932  n = (Node *) tle->expr;
933  }
934 
935  if (!foreign_expr_walker(n,
936  glob_cxt, &inner_cxt, case_arg_cxt))
937  return false;
938  }
939 
940  /*
941  * For aggorder elements, check whether the sort operator, if
942  * specified, is shippable or not.
943  */
944  if (agg->aggorder)
945  {
946  foreach(lc, agg->aggorder)
947  {
948  SortGroupClause *srt = (SortGroupClause *) lfirst(lc);
949  Oid sortcoltype;
950  TypeCacheEntry *typentry;
951  TargetEntry *tle;
952 
954  agg->args);
955  sortcoltype = exprType((Node *) tle->expr);
956  typentry = lookup_type_cache(sortcoltype,
958  /* Check shippability of non-default sort operator. */
959  if (srt->sortop != typentry->lt_opr &&
960  srt->sortop != typentry->gt_opr &&
961  !is_shippable(srt->sortop, OperatorRelationId,
962  fpinfo))
963  return false;
964  }
965  }
966 
967  /* Check aggregate filter */
968  if (!foreign_expr_walker((Node *) agg->aggfilter,
969  glob_cxt, &inner_cxt, case_arg_cxt))
970  return false;
971 
972  /*
973  * If aggregate's input collation is not derived from a
974  * foreign Var, it can't be sent to remote.
975  */
976  if (agg->inputcollid == InvalidOid)
977  /* OK, inputs are all noncollatable */ ;
978  else if (inner_cxt.state != FDW_COLLATE_SAFE ||
979  agg->inputcollid != inner_cxt.collation)
980  return false;
981 
982  /*
983  * Detect whether node is introducing a collation not derived
984  * from a foreign Var. (If so, we just mark it unsafe for now
985  * rather than immediately returning false, since the parent
986  * node might not care.)
987  */
988  collation = agg->aggcollid;
989  if (collation == InvalidOid)
991  else if (inner_cxt.state == FDW_COLLATE_SAFE &&
992  collation == inner_cxt.collation)
994  else if (collation == DEFAULT_COLLATION_OID)
996  else
998  }
999  break;
1000  default:
1001 
1002  /*
1003  * If it's anything else, assume it's unsafe. This list can be
1004  * expanded later, but don't forget to add deparse support below.
1005  */
1006  return false;
1007  }
1008 
1009  /*
1010  * If result type of given expression is not shippable, it can't be sent
1011  * to remote because it might have incompatible semantics on remote side.
1012  */
1013  if (check_type && !is_shippable(exprType(node), TypeRelationId, fpinfo))
1014  return false;
1015 
1016  /*
1017  * Now, merge my collation information into my parent's state.
1018  */
1019  if (state > outer_cxt->state)
1020  {
1021  /* Override previous parent state */
1022  outer_cxt->collation = collation;
1023  outer_cxt->state = state;
1024  }
1025  else if (state == outer_cxt->state)
1026  {
1027  /* Merge, or detect error if there's a collation conflict */
1028  switch (state)
1029  {
1030  case FDW_COLLATE_NONE:
1031  /* Nothing + nothing is still nothing */
1032  break;
1033  case FDW_COLLATE_SAFE:
1034  if (collation != outer_cxt->collation)
1035  {
1036  /*
1037  * Non-default collation always beats default.
1038  */
1039  if (outer_cxt->collation == DEFAULT_COLLATION_OID)
1040  {
1041  /* Override previous parent state */
1042  outer_cxt->collation = collation;
1043  }
1044  else if (collation != DEFAULT_COLLATION_OID)
1045  {
1046  /*
1047  * Conflict; show state as indeterminate. We don't
1048  * want to "return false" right away, since parent
1049  * node might not care about collation.
1050  */
1051  outer_cxt->state = FDW_COLLATE_UNSAFE;
1052  }
1053  }
1054  break;
1055  case FDW_COLLATE_UNSAFE:
1056  /* We're still conflicted ... */
1057  break;
1058  }
1059  }
1060 
1061  /* It looks OK */
1062  return true;
1063 }
1064 
1065 /*
1066  * Returns true if given expr is something we'd have to send the value of
1067  * to the foreign server.
1068  *
1069  * This should return true when the expression is a shippable node that
1070  * deparseExpr would add to context->params_list. Note that we don't care
1071  * if the expression *contains* such a node, only whether one appears at top
1072  * level. We need this to detect cases where setrefs.c would recognize a
1073  * false match between an fdw_exprs item (which came from the params_list)
1074  * and an entry in fdw_scan_tlist (which we're considering putting the given
1075  * expression into).
1076  */
1077 bool
1079  RelOptInfo *baserel,
1080  Expr *expr)
1081 {
1082  if (expr == NULL)
1083  return false;
1084 
1085  switch (nodeTag(expr))
1086  {
1087  case T_Var:
1088  {
1089  /* It would have to be sent unless it's a foreign Var */
1090  Var *var = (Var *) expr;
1091  PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) (baserel->fdw_private);
1092  Relids relids;
1093 
1094  if (IS_UPPER_REL(baserel))
1095  relids = fpinfo->outerrel->relids;
1096  else
1097  relids = baserel->relids;
1098 
1099  if (bms_is_member(var->varno, relids) && var->varlevelsup == 0)
1100  return false; /* foreign Var, so not a param */
1101  else
1102  return true; /* it'd have to be a param */
1103  break;
1104  }
1105  case T_Param:
1106  /* Params always have to be sent to the foreign server */
1107  return true;
1108  default:
1109  break;
1110  }
1111  return false;
1112 }
1113 
1114 /*
1115  * Returns true if it's safe to push down the sort expression described by
1116  * 'pathkey' to the foreign server.
1117  */
1118 bool
1120  RelOptInfo *baserel,
1121  PathKey *pathkey)
1122 {
1123  EquivalenceClass *pathkey_ec = pathkey->pk_eclass;
1124  PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) baserel->fdw_private;
1125 
1126  /*
1127  * is_foreign_expr would detect volatile expressions as well, but checking
1128  * ec_has_volatile here saves some cycles.
1129  */
1130  if (pathkey_ec->ec_has_volatile)
1131  return false;
1132 
1133  /* can't push down the sort if the pathkey's opfamily is not shippable */
1134  if (!is_shippable(pathkey->pk_opfamily, OperatorFamilyRelationId, fpinfo))
1135  return false;
1136 
1137  /* can push if a suitable EC member exists */
1138  return (find_em_for_rel(root, pathkey_ec, baserel) != NULL);
1139 }
1140 
1141 /*
1142  * Convert type OID + typmod info into a type name we can ship to the remote
1143  * server. Someplace else had better have verified that this type name is
1144  * expected to be known on the remote end.
1145  *
1146  * This is almost just format_type_with_typemod(), except that if left to its
1147  * own devices, that function will make schema-qualification decisions based
1148  * on the local search_path, which is wrong. We must schema-qualify all
1149  * type names that are not in pg_catalog. We assume here that built-in types
1150  * are all in pg_catalog and need not be qualified; otherwise, qualify.
1151  */
1152 static char *
1153 deparse_type_name(Oid type_oid, int32 typemod)
1154 {
1156 
1157  if (!is_builtin(type_oid))
1158  flags |= FORMAT_TYPE_FORCE_QUALIFY;
1159 
1160  return format_type_extended(type_oid, typemod, flags);
1161 }
1162 
1163 /*
1164  * Build the targetlist for given relation to be deparsed as SELECT clause.
1165  *
1166  * The output targetlist contains the columns that need to be fetched from the
1167  * foreign server for the given relation. If foreignrel is an upper relation,
1168  * then the output targetlist can also contain expressions to be evaluated on
1169  * foreign server.
1170  */
1171 List *
1173 {
1174  List *tlist = NIL;
1175  PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1176  ListCell *lc;
1177 
1178  /*
1179  * For an upper relation, we have already built the target list while
1180  * checking shippability, so just return that.
1181  */
1182  if (IS_UPPER_REL(foreignrel))
1183  return fpinfo->grouped_tlist;
1184 
1185  /*
1186  * We require columns specified in foreignrel->reltarget->exprs and those
1187  * required for evaluating the local conditions.
1188  */
1189  tlist = add_to_flat_tlist(tlist,
1190  pull_var_clause((Node *) foreignrel->reltarget->exprs,
1192  foreach(lc, fpinfo->local_conds)
1193  {
1194  RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
1195 
1196  tlist = add_to_flat_tlist(tlist,
1197  pull_var_clause((Node *) rinfo->clause,
1199  }
1200 
1201  return tlist;
1202 }
1203 
1204 /*
1205  * Deparse SELECT statement for given relation into buf.
1206  *
1207  * tlist contains the list of desired columns to be fetched from foreign server.
1208  * For a base relation fpinfo->attrs_used is used to construct SELECT clause,
1209  * hence the tlist is ignored for a base relation.
1210  *
1211  * remote_conds is the list of conditions to be deparsed into the WHERE clause
1212  * (or, in the case of upper relations, into the HAVING clause).
1213  *
1214  * If params_list is not NULL, it receives a list of Params and other-relation
1215  * Vars used in the clauses; these values must be transmitted to the remote
1216  * server as parameter values.
1217  *
1218  * If params_list is NULL, we're generating the query for EXPLAIN purposes,
1219  * so Params and other-relation Vars should be replaced by dummy values.
1220  *
1221  * pathkeys is the list of pathkeys to order the result by.
1222  *
1223  * is_subquery is the flag to indicate whether to deparse the specified
1224  * relation as a subquery.
1225  *
1226  * List of columns selected is returned in retrieved_attrs.
1227  */
1228 void
1230  List *tlist, List *remote_conds, List *pathkeys,
1231  bool has_final_sort, bool has_limit, bool is_subquery,
1232  List **retrieved_attrs, List **params_list)
1233 {
1234  deparse_expr_cxt context;
1235  PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) rel->fdw_private;
1236  List *quals;
1237 
1238  /*
1239  * We handle relations for foreign tables, joins between those and upper
1240  * relations.
1241  */
1242  Assert(IS_JOIN_REL(rel) || IS_SIMPLE_REL(rel) || IS_UPPER_REL(rel));
1243 
1244  /* Fill portions of context common to upper, join and base relation */
1245  context.buf = buf;
1246  context.root = root;
1247  context.foreignrel = rel;
1248  context.scanrel = IS_UPPER_REL(rel) ? fpinfo->outerrel : rel;
1249  context.params_list = params_list;
1250 
1251  /* Construct SELECT clause */
1252  deparseSelectSql(tlist, is_subquery, retrieved_attrs, &context);
1253 
1254  /*
1255  * For upper relations, the WHERE clause is built from the remote
1256  * conditions of the underlying scan relation; otherwise, we can use the
1257  * supplied list of remote conditions directly.
1258  */
1259  if (IS_UPPER_REL(rel))
1260  {
1261  PgFdwRelationInfo *ofpinfo;
1262 
1263  ofpinfo = (PgFdwRelationInfo *) fpinfo->outerrel->fdw_private;
1264  quals = ofpinfo->remote_conds;
1265  }
1266  else
1267  quals = remote_conds;
1268 
1269  /* Construct FROM and WHERE clauses */
1270  deparseFromExpr(quals, &context);
1271 
1272  if (IS_UPPER_REL(rel))
1273  {
1274  /* Append GROUP BY clause */
1275  appendGroupByClause(tlist, &context);
1276 
1277  /* Append HAVING clause */
1278  if (remote_conds)
1279  {
1280  appendStringInfoString(buf, " HAVING ");
1281  appendConditions(remote_conds, &context);
1282  }
1283  }
1284 
1285  /* Add ORDER BY clause if we found any useful pathkeys */
1286  if (pathkeys)
1287  appendOrderByClause(pathkeys, has_final_sort, &context);
1288 
1289  /* Add LIMIT clause if necessary */
1290  if (has_limit)
1291  appendLimitClause(&context);
1292 
1293  /* Add any necessary FOR UPDATE/SHARE. */
1294  deparseLockingClause(&context);
1295 }
1296 
1297 /*
1298  * Construct a simple SELECT statement that retrieves desired columns
1299  * of the specified foreign table, and append it to "buf". The output
1300  * contains just "SELECT ... ".
1301  *
1302  * We also create an integer List of the columns being retrieved, which is
1303  * returned to *retrieved_attrs, unless we deparse the specified relation
1304  * as a subquery.
1305  *
1306  * tlist is the list of desired columns. is_subquery is the flag to
1307  * indicate whether to deparse the specified relation as a subquery.
1308  * Read prologue of deparseSelectStmtForRel() for details.
1309  */
1310 static void
1311 deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_attrs,
1312  deparse_expr_cxt *context)
1313 {
1314  StringInfo buf = context->buf;
1315  RelOptInfo *foreignrel = context->foreignrel;
1316  PlannerInfo *root = context->root;
1317  PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1318 
1319  /*
1320  * Construct SELECT list
1321  */
1322  appendStringInfoString(buf, "SELECT ");
1323 
1324  if (is_subquery)
1325  {
1326  /*
1327  * For a relation that is deparsed as a subquery, emit expressions
1328  * specified in the relation's reltarget. Note that since this is for
1329  * the subquery, no need to care about *retrieved_attrs.
1330  */
1331  deparseSubqueryTargetList(context);
1332  }
1333  else if (IS_JOIN_REL(foreignrel) || IS_UPPER_REL(foreignrel))
1334  {
1335  /*
1336  * For a join or upper relation the input tlist gives the list of
1337  * columns required to be fetched from the foreign server.
1338  */
1339  deparseExplicitTargetList(tlist, false, retrieved_attrs, context);
1340  }
1341  else
1342  {
1343  /*
1344  * For a base relation fpinfo->attrs_used gives the list of columns
1345  * required to be fetched from the foreign server.
1346  */
1347  RangeTblEntry *rte = planner_rt_fetch(foreignrel->relid, root);
1348 
1349  /*
1350  * Core code already has some lock on each rel being planned, so we
1351  * can use NoLock here.
1352  */
1353  Relation rel = table_open(rte->relid, NoLock);
1354 
1355  deparseTargetList(buf, rte, foreignrel->relid, rel, false,
1356  fpinfo->attrs_used, false, retrieved_attrs);
1357  table_close(rel, NoLock);
1358  }
1359 }
1360 
1361 /*
1362  * Construct a FROM clause and, if needed, a WHERE clause, and append those to
1363  * "buf".
1364  *
1365  * quals is the list of clauses to be included in the WHERE clause.
1366  * (These may or may not include RestrictInfo decoration.)
1367  */
1368 static void
1370 {
1371  StringInfo buf = context->buf;
1372  RelOptInfo *scanrel = context->scanrel;
1373 
1374  /* For upper relations, scanrel must be either a joinrel or a baserel */
1375  Assert(!IS_UPPER_REL(context->foreignrel) ||
1376  IS_JOIN_REL(scanrel) || IS_SIMPLE_REL(scanrel));
1377 
1378  /* Construct FROM clause */
1379  appendStringInfoString(buf, " FROM ");
1380  deparseFromExprForRel(buf, context->root, scanrel,
1381  (bms_membership(scanrel->relids) == BMS_MULTIPLE),
1382  (Index) 0, NULL, context->params_list);
1383 
1384  /* Construct WHERE clause */
1385  if (quals != NIL)
1386  {
1387  appendStringInfoString(buf, " WHERE ");
1388  appendConditions(quals, context);
1389  }
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
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. */
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 ||
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  */
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,
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
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
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 /* Output join name for given join type */
1602 const char *
1604 {
1605  switch (jointype)
1606  {
1607  case JOIN_INNER:
1608  return "INNER";
1609 
1610  case JOIN_LEFT:
1611  return "LEFT";
1612 
1613  case JOIN_RIGHT:
1614  return "RIGHT";
1615 
1616  case JOIN_FULL:
1617  return "FULL";
1618 
1619  default:
1620  /* Shouldn't come here, but protect from buggy code. */
1621  elog(ERROR, "unsupported join type %d", jointype);
1622  }
1623 
1624  /* Keep compiler happy */
1625  return NULL;
1626 }
1627 
1628 /*
1629  * Deparse given targetlist and append it to context->buf.
1630  *
1631  * tlist is list of TargetEntry's which in turn contain Var nodes.
1632  *
1633  * retrieved_attrs is the list of continuously increasing integers starting
1634  * from 1. It has same number of entries as tlist.
1635  *
1636  * This is used for both SELECT and RETURNING targetlists; the is_returning
1637  * parameter is true only for a RETURNING targetlist.
1638  */
1639 static void
1641  bool is_returning,
1642  List **retrieved_attrs,
1643  deparse_expr_cxt *context)
1644 {
1645  ListCell *lc;
1646  StringInfo buf = context->buf;
1647  int i = 0;
1648 
1649  *retrieved_attrs = NIL;
1650 
1651  foreach(lc, tlist)
1652  {
1653  TargetEntry *tle = lfirst_node(TargetEntry, lc);
1654 
1655  if (i > 0)
1656  appendStringInfoString(buf, ", ");
1657  else if (is_returning)
1658  appendStringInfoString(buf, " RETURNING ");
1659 
1660  deparseExpr((Expr *) tle->expr, context);
1661 
1662  *retrieved_attrs = lappend_int(*retrieved_attrs, i + 1);
1663  i++;
1664  }
1665 
1666  if (i == 0 && !is_returning)
1667  appendStringInfoString(buf, "NULL");
1668 }
1669 
1670 /*
1671  * Emit expressions specified in the given relation's reltarget.
1672  *
1673  * This is used for deparsing the given relation as a subquery.
1674  */
1675 static void
1677 {
1678  StringInfo buf = context->buf;
1679  RelOptInfo *foreignrel = context->foreignrel;
1680  bool first;
1681  ListCell *lc;
1682 
1683  /* Should only be called in these cases. */
1684  Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
1685 
1686  first = true;
1687  foreach(lc, foreignrel->reltarget->exprs)
1688  {
1689  Node *node = (Node *) lfirst(lc);
1690 
1691  if (!first)
1692  appendStringInfoString(buf, ", ");
1693  first = false;
1694 
1695  deparseExpr((Expr *) node, context);
1696  }
1697 
1698  /* Don't generate bad syntax if no expressions */
1699  if (first)
1700  appendStringInfoString(buf, "NULL");
1701 }
1702 
1703 /*
1704  * Construct FROM clause for given relation
1705  *
1706  * The function constructs ... JOIN ... ON ... for join relation. For a base
1707  * relation it just returns schema-qualified tablename, with the appropriate
1708  * alias if so requested.
1709  *
1710  * 'ignore_rel' is either zero or the RT index of a target relation. In the
1711  * latter case the function constructs FROM clause of UPDATE or USING clause
1712  * of DELETE; it deparses the join relation as if the relation never contained
1713  * the target relation, and creates a List of conditions to be deparsed into
1714  * the top-level WHERE clause, which is returned to *ignore_conds.
1715  */
1716 static void
1718  bool use_alias, Index ignore_rel, List **ignore_conds,
1719  List **params_list)
1720 {
1721  PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1722 
1723  if (IS_JOIN_REL(foreignrel))
1724  {
1725  StringInfoData join_sql_o;
1726  StringInfoData join_sql_i;
1727  RelOptInfo *outerrel = fpinfo->outerrel;
1728  RelOptInfo *innerrel = fpinfo->innerrel;
1729  bool outerrel_is_target = false;
1730  bool innerrel_is_target = false;
1731 
1732  if (ignore_rel > 0 && bms_is_member(ignore_rel, foreignrel->relids))
1733  {
1734  /*
1735  * If this is an inner join, add joinclauses to *ignore_conds and
1736  * set it to empty so that those can be deparsed into the WHERE
1737  * clause. Note that since the target relation can never be
1738  * within the nullable side of an outer join, those could safely
1739  * be pulled up into the WHERE clause (see foreign_join_ok()).
1740  * Note also that since the target relation is only inner-joined
1741  * to any other relation in the query, all conditions in the join
1742  * tree mentioning the target relation could be deparsed into the
1743  * WHERE clause by doing this recursively.
1744  */
1745  if (fpinfo->jointype == JOIN_INNER)
1746  {
1747  *ignore_conds = list_concat(*ignore_conds,
1748  fpinfo->joinclauses);
1749  fpinfo->joinclauses = NIL;
1750  }
1751 
1752  /*
1753  * Check if either of the input relations is the target relation.
1754  */
1755  if (outerrel->relid == ignore_rel)
1756  outerrel_is_target = true;
1757  else if (innerrel->relid == ignore_rel)
1758  innerrel_is_target = true;
1759  }
1760 
1761  /* Deparse outer relation if not the target relation. */
1762  if (!outerrel_is_target)
1763  {
1764  initStringInfo(&join_sql_o);
1765  deparseRangeTblRef(&join_sql_o, root, outerrel,
1766  fpinfo->make_outerrel_subquery,
1767  ignore_rel, ignore_conds, params_list);
1768 
1769  /*
1770  * If inner relation is the target relation, skip deparsing it.
1771  * Note that since the join of the target relation with any other
1772  * relation in the query is an inner join and can never be within
1773  * the nullable side of an outer join, the join could be
1774  * interchanged with higher-level joins (cf. identity 1 on outer
1775  * join reordering shown in src/backend/optimizer/README), which
1776  * means it's safe to skip the target-relation deparsing here.
1777  */
1778  if (innerrel_is_target)
1779  {
1780  Assert(fpinfo->jointype == JOIN_INNER);
1781  Assert(fpinfo->joinclauses == NIL);
1782  appendBinaryStringInfo(buf, join_sql_o.data, join_sql_o.len);
1783  return;
1784  }
1785  }
1786 
1787  /* Deparse inner relation if not the target relation. */
1788  if (!innerrel_is_target)
1789  {
1790  initStringInfo(&join_sql_i);
1791  deparseRangeTblRef(&join_sql_i, root, innerrel,
1792  fpinfo->make_innerrel_subquery,
1793  ignore_rel, ignore_conds, params_list);
1794 
1795  /*
1796  * If outer relation is the target relation, skip deparsing it.
1797  * See the above note about safety.
1798  */
1799  if (outerrel_is_target)
1800  {
1801  Assert(fpinfo->jointype == JOIN_INNER);
1802  Assert(fpinfo->joinclauses == NIL);
1803  appendBinaryStringInfo(buf, join_sql_i.data, join_sql_i.len);
1804  return;
1805  }
1806  }
1807 
1808  /* Neither of the relations is the target relation. */
1809  Assert(!outerrel_is_target && !innerrel_is_target);
1810 
1811  /*
1812  * For a join relation FROM clause entry is deparsed as
1813  *
1814  * ((outer relation) <join type> (inner relation) ON (joinclauses))
1815  */
1816  appendStringInfo(buf, "(%s %s JOIN %s ON ", join_sql_o.data,
1817  get_jointype_name(fpinfo->jointype), join_sql_i.data);
1818 
1819  /* Append join clause; (TRUE) if no join clause */
1820  if (fpinfo->joinclauses)
1821  {
1822  deparse_expr_cxt context;
1823 
1824  context.buf = buf;
1825  context.foreignrel = foreignrel;
1826  context.scanrel = foreignrel;
1827  context.root = root;
1828  context.params_list = params_list;
1829 
1830  appendStringInfoChar(buf, '(');
1831  appendConditions(fpinfo->joinclauses, &context);
1832  appendStringInfoChar(buf, ')');
1833  }
1834  else
1835  appendStringInfoString(buf, "(TRUE)");
1836 
1837  /* End the FROM clause entry. */
1838  appendStringInfoChar(buf, ')');
1839  }
1840  else
1841  {
1842  RangeTblEntry *rte = planner_rt_fetch(foreignrel->relid, root);
1843 
1844  /*
1845  * Core code already has some lock on each rel being planned, so we
1846  * can use NoLock here.
1847  */
1848  Relation rel = table_open(rte->relid, NoLock);
1849 
1850  deparseRelation(buf, rel);
1851 
1852  /*
1853  * Add a unique alias to avoid any conflict in relation names due to
1854  * pulled up subqueries in the query being built for a pushed down
1855  * join.
1856  */
1857  if (use_alias)
1858  appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, foreignrel->relid);
1859 
1860  table_close(rel, NoLock);
1861  }
1862 }
1863 
1864 /*
1865  * Append FROM clause entry for the given relation into buf.
1866  */
1867 static void
1869  bool make_subquery, Index ignore_rel, List **ignore_conds,
1870  List **params_list)
1871 {
1872  PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1873 
1874  /* Should only be called in these cases. */
1875  Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
1876 
1877  Assert(fpinfo->local_conds == NIL);
1878 
1879  /* If make_subquery is true, deparse the relation as a subquery. */
1880  if (make_subquery)
1881  {
1882  List *retrieved_attrs;
1883  int ncols;
1884 
1885  /*
1886  * The given relation shouldn't contain the target relation, because
1887  * this should only happen for input relations for a full join, and
1888  * such relations can never contain an UPDATE/DELETE target.
1889  */
1890  Assert(ignore_rel == 0 ||
1891  !bms_is_member(ignore_rel, foreignrel->relids));
1892 
1893  /* Deparse the subquery representing the relation. */
1894  appendStringInfoChar(buf, '(');
1895  deparseSelectStmtForRel(buf, root, foreignrel, NIL,
1896  fpinfo->remote_conds, NIL,
1897  false, false, true,
1898  &retrieved_attrs, params_list);
1899  appendStringInfoChar(buf, ')');
1900 
1901  /* Append the relation alias. */
1903  fpinfo->relation_index);
1904 
1905  /*
1906  * Append the column aliases if needed. Note that the subquery emits
1907  * expressions specified in the relation's reltarget (see
1908  * deparseSubqueryTargetList).
1909  */
1910  ncols = list_length(foreignrel->reltarget->exprs);
1911  if (ncols > 0)
1912  {
1913  int i;
1914 
1915  appendStringInfoChar(buf, '(');
1916  for (i = 1; i <= ncols; i++)
1917  {
1918  if (i > 1)
1919  appendStringInfoString(buf, ", ");
1920 
1922  }
1923  appendStringInfoChar(buf, ')');
1924  }
1925  }
1926  else
1927  deparseFromExprForRel(buf, root, foreignrel, true, ignore_rel,
1928  ignore_conds, params_list);
1929 }
1930 
1931 /*
1932  * deparse remote INSERT statement
1933  *
1934  * The statement text is appended to buf, and we also create an integer List
1935  * of the columns being retrieved by WITH CHECK OPTION or RETURNING (if any),
1936  * which is returned to *retrieved_attrs.
1937  *
1938  * This also stores end position of the VALUES clause, so that we can rebuild
1939  * an INSERT for a batch of rows later.
1940  */
1941 void
1943  Index rtindex, Relation rel,
1944  List *targetAttrs, bool doNothing,
1945  List *withCheckOptionList, List *returningList,
1946  List **retrieved_attrs, int *values_end_len)
1947 {
1948  TupleDesc tupdesc = RelationGetDescr(rel);
1949  AttrNumber pindex;
1950  bool first;
1951  ListCell *lc;
1952 
1953  appendStringInfoString(buf, "INSERT INTO ");
1954  deparseRelation(buf, rel);
1955 
1956  if (targetAttrs)
1957  {
1958  appendStringInfoChar(buf, '(');
1959 
1960  first = true;
1961  foreach(lc, targetAttrs)
1962  {
1963  int attnum = lfirst_int(lc);
1964 
1965  if (!first)
1966  appendStringInfoString(buf, ", ");
1967  first = false;
1968 
1969  deparseColumnRef(buf, rtindex, attnum, rte, false);
1970  }
1971 
1972  appendStringInfoString(buf, ") VALUES (");
1973 
1974  pindex = 1;
1975  first = true;
1976  foreach(lc, targetAttrs)
1977  {
1978  int attnum = lfirst_int(lc);
1979  Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
1980 
1981  if (!first)
1982  appendStringInfoString(buf, ", ");
1983  first = false;
1984 
1985  if (attr->attgenerated)
1986  appendStringInfoString(buf, "DEFAULT");
1987  else
1988  {
1989  appendStringInfo(buf, "$%d", pindex);
1990  pindex++;
1991  }
1992  }
1993 
1994  appendStringInfoChar(buf, ')');
1995  }
1996  else
1997  appendStringInfoString(buf, " DEFAULT VALUES");
1998  *values_end_len = buf->len;
1999 
2000  if (doNothing)
2001  appendStringInfoString(buf, " ON CONFLICT DO NOTHING");
2002 
2003  deparseReturningList(buf, rte, rtindex, rel,
2004  rel->trigdesc && rel->trigdesc->trig_insert_after_row,
2005  withCheckOptionList, returningList, retrieved_attrs);
2006 }
2007 
2008 /*
2009  * rebuild remote INSERT statement
2010  *
2011  * Provided a number of rows in a batch, builds INSERT statement with the
2012  * right number of parameters.
2013  */
2014 void
2016  char *orig_query, List *target_attrs,
2017  int values_end_len, int num_params,
2018  int num_rows)
2019 {
2020  TupleDesc tupdesc = RelationGetDescr(rel);
2021  int i;
2022  int pindex;
2023  bool first;
2024  ListCell *lc;
2025 
2026  /* Make sure the values_end_len is sensible */
2027  Assert((values_end_len > 0) && (values_end_len <= strlen(orig_query)));
2028 
2029  /* Copy up to the end of the first record from the original query */
2030  appendBinaryStringInfo(buf, orig_query, values_end_len);
2031 
2032  /*
2033  * Add records to VALUES clause (we already have parameters for the first
2034  * row, so start at the right offset).
2035  */
2036  pindex = num_params + 1;
2037  for (i = 0; i < num_rows; i++)
2038  {
2039  appendStringInfoString(buf, ", (");
2040 
2041  first = true;
2042  foreach(lc, target_attrs)
2043  {
2044  int attnum = lfirst_int(lc);
2045  Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
2046 
2047  if (!first)
2048  appendStringInfoString(buf, ", ");
2049  first = false;
2050 
2051  if (attr->attgenerated)
2052  appendStringInfoString(buf, "DEFAULT");
2053  else
2054  {
2055  appendStringInfo(buf, "$%d", pindex);
2056  pindex++;
2057  }
2058  }
2059 
2060  appendStringInfoChar(buf, ')');
2061  }
2062 
2063  /* Copy stuff after VALUES clause from the original query */
2064  appendStringInfoString(buf, orig_query + values_end_len);
2065 }
2066 
2067 /*
2068  * deparse remote UPDATE statement
2069  *
2070  * The statement text is appended to buf, and we also create an integer List
2071  * of the columns being retrieved by WITH CHECK OPTION or RETURNING (if any),
2072  * which is returned to *retrieved_attrs.
2073  */
2074 void
2076  Index rtindex, Relation rel,
2077  List *targetAttrs,
2078  List *withCheckOptionList, List *returningList,
2079  List **retrieved_attrs)
2080 {
2081  TupleDesc tupdesc = RelationGetDescr(rel);
2082  AttrNumber pindex;
2083  bool first;
2084  ListCell *lc;
2085 
2086  appendStringInfoString(buf, "UPDATE ");
2087  deparseRelation(buf, rel);
2088  appendStringInfoString(buf, " SET ");
2089 
2090  pindex = 2; /* ctid is always the first param */
2091  first = true;
2092  foreach(lc, targetAttrs)
2093  {
2094  int attnum = lfirst_int(lc);
2095  Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
2096 
2097  if (!first)
2098  appendStringInfoString(buf, ", ");
2099  first = false;
2100 
2101  deparseColumnRef(buf, rtindex, attnum, rte, false);
2102  if (attr->attgenerated)
2103  appendStringInfoString(buf, " = DEFAULT");
2104  else
2105  {
2106  appendStringInfo(buf, " = $%d", pindex);
2107  pindex++;
2108  }
2109  }
2110  appendStringInfoString(buf, " WHERE ctid = $1");
2111 
2112  deparseReturningList(buf, rte, rtindex, rel,
2113  rel->trigdesc && rel->trigdesc->trig_update_after_row,
2114  withCheckOptionList, returningList, retrieved_attrs);
2115 }
2116 
2117 /*
2118  * deparse remote UPDATE statement
2119  *
2120  * 'buf' is the output buffer to append the statement to
2121  * 'rtindex' is the RT index of the associated target relation
2122  * 'rel' is the relation descriptor for the target relation
2123  * 'foreignrel' is the RelOptInfo for the target relation or the join relation
2124  * containing all base relations in the query
2125  * 'targetlist' is the tlist of the underlying foreign-scan plan node
2126  * (note that this only contains new-value expressions and junk attrs)
2127  * 'targetAttrs' is the target columns of the UPDATE
2128  * 'remote_conds' is the qual clauses that must be evaluated remotely
2129  * '*params_list' is an output list of exprs that will become remote Params
2130  * 'returningList' is the RETURNING targetlist
2131  * '*retrieved_attrs' is an output list of integers of columns being retrieved
2132  * by RETURNING (if any)
2133  */
2134 void
2136  Index rtindex, Relation rel,
2137  RelOptInfo *foreignrel,
2138  List *targetlist,
2139  List *targetAttrs,
2140  List *remote_conds,
2141  List **params_list,
2142  List *returningList,
2143  List **retrieved_attrs)
2144 {
2145  deparse_expr_cxt context;
2146  int nestlevel;
2147  bool first;
2148  RangeTblEntry *rte = planner_rt_fetch(rtindex, root);
2149  ListCell *lc,
2150  *lc2;
2151 
2152  /* Set up context struct for recursion */
2153  context.root = root;
2154  context.foreignrel = foreignrel;
2155  context.scanrel = foreignrel;
2156  context.buf = buf;
2157  context.params_list = params_list;
2158 
2159  appendStringInfoString(buf, "UPDATE ");
2160  deparseRelation(buf, rel);
2161  if (foreignrel->reloptkind == RELOPT_JOINREL)
2162  appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, rtindex);
2163  appendStringInfoString(buf, " SET ");
2164 
2165  /* Make sure any constants in the exprs are printed portably */
2166  nestlevel = set_transmission_modes();
2167 
2168  first = true;
2169  forboth(lc, targetlist, lc2, targetAttrs)
2170  {
2171  TargetEntry *tle = lfirst_node(TargetEntry, lc);
2172  int attnum = lfirst_int(lc2);
2173 
2174  /* update's new-value expressions shouldn't be resjunk */
2175  Assert(!tle->resjunk);
2176 
2177  if (!first)
2178  appendStringInfoString(buf, ", ");
2179  first = false;
2180 
2181  deparseColumnRef(buf, rtindex, attnum, rte, false);
2182  appendStringInfoString(buf, " = ");
2183  deparseExpr((Expr *) tle->expr, &context);
2184  }
2185 
2186  reset_transmission_modes(nestlevel);
2187 
2188  if (foreignrel->reloptkind == RELOPT_JOINREL)
2189  {
2190  List *ignore_conds = NIL;
2191 
2192  appendStringInfoString(buf, " FROM ");
2193  deparseFromExprForRel(buf, root, foreignrel, true, rtindex,
2194  &ignore_conds, params_list);
2195  remote_conds = list_concat(remote_conds, ignore_conds);
2196  }
2197 
2198  if (remote_conds)
2199  {
2200  appendStringInfoString(buf, " WHERE ");
2201  appendConditions(remote_conds, &context);
2202  }
2203 
2204  if (foreignrel->reloptkind == RELOPT_JOINREL)
2205  deparseExplicitTargetList(returningList, true, retrieved_attrs,
2206  &context);
2207  else
2208  deparseReturningList(buf, rte, rtindex, rel, false,
2209  NIL, returningList, retrieved_attrs);
2210 }
2211 
2212 /*
2213  * deparse remote DELETE statement
2214  *
2215  * The statement text is appended to buf, and we also create an integer List
2216  * of the columns being retrieved by RETURNING (if any), which is returned
2217  * to *retrieved_attrs.
2218  */
2219 void
2221  Index rtindex, Relation rel,
2222  List *returningList,
2223  List **retrieved_attrs)
2224 {
2225  appendStringInfoString(buf, "DELETE FROM ");
2226  deparseRelation(buf, rel);
2227  appendStringInfoString(buf, " WHERE ctid = $1");
2228 
2229  deparseReturningList(buf, rte, rtindex, rel,
2230  rel->trigdesc && rel->trigdesc->trig_delete_after_row,
2231  NIL, returningList, retrieved_attrs);
2232 }
2233 
2234 /*
2235  * deparse remote DELETE statement
2236  *
2237  * 'buf' is the output buffer to append the statement to
2238  * 'rtindex' is the RT index of the associated target relation
2239  * 'rel' is the relation descriptor for the target relation
2240  * 'foreignrel' is the RelOptInfo for the target relation or the join relation
2241  * containing all base relations in the query
2242  * 'remote_conds' is the qual clauses that must be evaluated remotely
2243  * '*params_list' is an output list of exprs that will become remote Params
2244  * 'returningList' is the RETURNING targetlist
2245  * '*retrieved_attrs' is an output list of integers of columns being retrieved
2246  * by RETURNING (if any)
2247  */
2248 void
2250  Index rtindex, Relation rel,
2251  RelOptInfo *foreignrel,
2252  List *remote_conds,
2253  List **params_list,
2254  List *returningList,
2255  List **retrieved_attrs)
2256 {
2257  deparse_expr_cxt context;
2258 
2259  /* Set up context struct for recursion */
2260  context.root = root;
2261  context.foreignrel = foreignrel;
2262  context.scanrel = foreignrel;
2263  context.buf = buf;
2264  context.params_list = params_list;
2265 
2266  appendStringInfoString(buf, "DELETE FROM ");
2267  deparseRelation(buf, rel);
2268  if (foreignrel->reloptkind == RELOPT_JOINREL)
2269  appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, rtindex);
2270 
2271  if (foreignrel->reloptkind == RELOPT_JOINREL)
2272  {
2273  List *ignore_conds = NIL;
2274 
2275  appendStringInfoString(buf, " USING ");
2276  deparseFromExprForRel(buf, root, foreignrel, true, rtindex,
2277  &ignore_conds, params_list);
2278  remote_conds = list_concat(remote_conds, ignore_conds);
2279  }
2280 
2281  if (remote_conds)
2282  {
2283  appendStringInfoString(buf, " WHERE ");
2284  appendConditions(remote_conds, &context);
2285  }
2286 
2287  if (foreignrel->reloptkind == RELOPT_JOINREL)
2288  deparseExplicitTargetList(returningList, true, retrieved_attrs,
2289  &context);
2290  else
2291  deparseReturningList(buf, planner_rt_fetch(rtindex, root),
2292  rtindex, rel, false,
2293  NIL, returningList, retrieved_attrs);
2294 }
2295 
2296 /*
2297  * Add a RETURNING clause, if needed, to an INSERT/UPDATE/DELETE.
2298  */
2299 static void
2301  Index rtindex, Relation rel,
2302  bool trig_after_row,
2303  List *withCheckOptionList,
2304  List *returningList,
2305  List **retrieved_attrs)
2306 {
2307  Bitmapset *attrs_used = NULL;
2308 
2309  if (trig_after_row)
2310  {
2311  /* whole-row reference acquires all non-system columns */
2312  attrs_used =
2314  }
2315 
2316  if (withCheckOptionList != NIL)
2317  {
2318  /*
2319  * We need the attrs, non-system and system, mentioned in the local
2320  * query's WITH CHECK OPTION list.
2321  *
2322  * Note: we do this to ensure that WCO constraints will be evaluated
2323  * on the data actually inserted/updated on the remote side, which
2324  * might differ from the data supplied by the core code, for example
2325  * as a result of remote triggers.
2326  */
2327  pull_varattnos((Node *) withCheckOptionList, rtindex,
2328  &attrs_used);
2329  }
2330 
2331  if (returningList != NIL)
2332  {
2333  /*
2334  * We need the attrs, non-system and system, mentioned in the local
2335  * query's RETURNING list.
2336  */
2337  pull_varattnos((Node *) returningList, rtindex,
2338  &attrs_used);
2339  }
2340 
2341  if (attrs_used != NULL)
2342  deparseTargetList(buf, rte, rtindex, rel, true, attrs_used, false,
2343  retrieved_attrs);
2344  else
2345  *retrieved_attrs = NIL;
2346 }
2347 
2348 /*
2349  * Construct SELECT statement to acquire size in blocks of given relation.
2350  *
2351  * Note: we use local definition of block size, not remote definition.
2352  * This is perhaps debatable.
2353  *
2354  * Note: pg_relation_size() exists in 8.1 and later.
2355  */
2356 void
2358 {
2360 
2361  /* We'll need the remote relation name as a literal. */
2363  deparseRelation(&relname, rel);
2364 
2365  appendStringInfoString(buf, "SELECT pg_catalog.pg_relation_size(");
2367  appendStringInfo(buf, "::pg_catalog.regclass) / %d", BLCKSZ);
2368 }
2369 
2370 /*
2371  * Construct SELECT statement to acquire sample rows of given relation.
2372  *
2373  * SELECT command is appended to buf, and list of columns retrieved
2374  * is returned to *retrieved_attrs.
2375  */
2376 void
2378 {
2379  Oid relid = RelationGetRelid(rel);
2380  TupleDesc tupdesc = RelationGetDescr(rel);
2381  int i;
2382  char *colname;
2383  List *options;
2384  ListCell *lc;
2385  bool first = true;
2386 
2387  *retrieved_attrs = NIL;
2388 
2389  appendStringInfoString(buf, "SELECT ");
2390  for (i = 0; i < tupdesc->natts; i++)
2391  {
2392  /* Ignore dropped columns. */
2393  if (TupleDescAttr(tupdesc, i)->attisdropped)
2394  continue;
2395 
2396  if (!first)
2397  appendStringInfoString(buf, ", ");
2398  first = false;
2399 
2400  /* Use attribute name or column_name option. */
2401  colname = NameStr(TupleDescAttr(tupdesc, i)->attname);
2402  options = GetForeignColumnOptions(relid, i + 1);
2403 
2404  foreach(lc, options)
2405  {
2406  DefElem *def = (DefElem *) lfirst(lc);
2407 
2408  if (strcmp(def->defname, "column_name") == 0)
2409  {
2410  colname = defGetString(def);
2411  break;
2412  }
2413  }
2414 
2416 
2417  *retrieved_attrs = lappend_int(*retrieved_attrs, i + 1);
2418  }
2419 
2420  /* Don't generate bad syntax for zero-column relation. */
2421  if (first)
2422  appendStringInfoString(buf, "NULL");
2423 
2424  /*
2425  * Construct FROM clause
2426  */
2427  appendStringInfoString(buf, " FROM ");
2428  deparseRelation(buf, rel);
2429 }
2430 
2431 /*
2432  * Construct a simple "TRUNCATE rel" statement
2433  */
2434 void
2436  List *rels,
2437  DropBehavior behavior,
2438  bool restart_seqs)
2439 {
2440  ListCell *cell;
2441 
2442  appendStringInfoString(buf, "TRUNCATE ");
2443 
2444  foreach(cell, rels)
2445  {
2446  Relation rel = lfirst(cell);
2447 
2448  if (cell != list_head(rels))
2449  appendStringInfoString(buf, ", ");
2450 
2451  deparseRelation(buf, rel);
2452  }
2453 
2454  appendStringInfo(buf, " %s IDENTITY",
2455  restart_seqs ? "RESTART" : "CONTINUE");
2456 
2457  if (behavior == DROP_RESTRICT)
2458  appendStringInfoString(buf, " RESTRICT");
2459  else if (behavior == DROP_CASCADE)
2460  appendStringInfoString(buf, " CASCADE");
2461 }
2462 
2463 /*
2464  * Construct name to use for given column, and emit it into buf.
2465  * If it has a column_name FDW option, use that instead of attribute name.
2466  *
2467  * If qualify_col is true, qualify column name with the alias of relation.
2468  */
2469 static void
2470 deparseColumnRef(StringInfo buf, int varno, int varattno, RangeTblEntry *rte,
2471  bool qualify_col)
2472 {
2473  /* We support fetching the remote side's CTID and OID. */
2474  if (varattno == SelfItemPointerAttributeNumber)
2475  {
2476  if (qualify_col)
2477  ADD_REL_QUALIFIER(buf, varno);
2478  appendStringInfoString(buf, "ctid");
2479  }
2480  else if (varattno < 0)
2481  {
2482  /*
2483  * All other system attributes are fetched as 0, except for table OID,
2484  * which is fetched as the local table OID. However, we must be
2485  * careful; the table could be beneath an outer join, in which case it
2486  * must go to NULL whenever the rest of the row does.
2487  */
2488  Oid fetchval = 0;
2489 
2490  if (varattno == TableOidAttributeNumber)
2491  fetchval = rte->relid;
2492 
2493  if (qualify_col)
2494  {
2495  appendStringInfoString(buf, "CASE WHEN (");
2496  ADD_REL_QUALIFIER(buf, varno);
2497  appendStringInfo(buf, "*)::text IS NOT NULL THEN %u END", fetchval);
2498  }
2499  else
2500  appendStringInfo(buf, "%u", fetchval);
2501  }
2502  else if (varattno == 0)
2503  {
2504  /* Whole row reference */
2505  Relation rel;
2506  Bitmapset *attrs_used;
2507 
2508  /* Required only to be passed down to deparseTargetList(). */
2509  List *retrieved_attrs;
2510 
2511  /*
2512  * The lock on the relation will be held by upper callers, so it's
2513  * fine to open it with no lock here.
2514  */
2515  rel = table_open(rte->relid, NoLock);
2516 
2517  /*
2518  * The local name of the foreign table can not be recognized by the
2519  * foreign server and the table it references on foreign server might
2520  * have different column ordering or different columns than those
2521  * declared locally. Hence we have to deparse whole-row reference as
2522  * ROW(columns referenced locally). Construct this by deparsing a
2523  * "whole row" attribute.
2524  */
2525  attrs_used = bms_add_member(NULL,
2527 
2528  /*
2529  * In case the whole-row reference is under an outer join then it has
2530  * to go NULL whenever the rest of the row goes NULL. Deparsing a join
2531  * query would always involve multiple relations, thus qualify_col
2532  * would be true.
2533  */
2534  if (qualify_col)
2535  {
2536  appendStringInfoString(buf, "CASE WHEN (");
2537  ADD_REL_QUALIFIER(buf, varno);
2538  appendStringInfoString(buf, "*)::text IS NOT NULL THEN ");
2539  }
2540 
2541  appendStringInfoString(buf, "ROW(");
2542  deparseTargetList(buf, rte, varno, rel, false, attrs_used, qualify_col,
2543  &retrieved_attrs);
2544  appendStringInfoChar(buf, ')');
2545 
2546  /* Complete the CASE WHEN statement started above. */
2547  if (qualify_col)
2548  appendStringInfoString(buf, " END");
2549 
2550  table_close(rel, NoLock);
2551  bms_free(attrs_used);
2552  }
2553  else
2554  {
2555  char *colname = NULL;
2556  List *options;
2557  ListCell *lc;
2558 
2559  /* varno must not be any of OUTER_VAR, INNER_VAR and INDEX_VAR. */
2560  Assert(!IS_SPECIAL_VARNO(varno));
2561 
2562  /*
2563  * If it's a column of a foreign table, and it has the column_name FDW
2564  * option, use that value.
2565  */
2566  options = GetForeignColumnOptions(rte->relid, varattno);
2567  foreach(lc, options)
2568  {
2569  DefElem *def = (DefElem *) lfirst(lc);
2570 
2571  if (strcmp(def->defname, "column_name") == 0)
2572  {
2573  colname = defGetString(def);
2574  break;
2575  }
2576  }
2577 
2578  /*
2579  * If it's a column of a regular table or it doesn't have column_name
2580  * FDW option, use attribute name.
2581  */
2582  if (colname == NULL)
2583  colname = get_attname(rte->relid, varattno, false);
2584 
2585  if (qualify_col)
2586  ADD_REL_QUALIFIER(buf, varno);
2587 
2589  }
2590 }
2591 
2592 /*
2593  * Append remote name of specified foreign table to buf.
2594  * Use value of table_name FDW option (if any) instead of relation's name.
2595  * Similarly, schema_name FDW option overrides schema name.
2596  */
2597 static void
2599 {
2600  ForeignTable *table;
2601  const char *nspname = NULL;
2602  const char *relname = NULL;
2603  ListCell *lc;
2604 
2605  /* obtain additional catalog information. */
2606  table = GetForeignTable(RelationGetRelid(rel));
2607 
2608  /*
2609  * Use value of FDW options if any, instead of the name of object itself.
2610  */
2611  foreach(lc, table->options)
2612  {
2613  DefElem *def = (DefElem *) lfirst(lc);
2614 
2615  if (strcmp(def->defname, "schema_name") == 0)
2616  nspname = defGetString(def);
2617  else if (strcmp(def->defname, "table_name") == 0)
2618  relname = defGetString(def);
2619  }
2620 
2621  /*
2622  * Note: we could skip printing the schema name if it's pg_catalog, but
2623  * that doesn't seem worth the trouble.
2624  */
2625  if (nspname == NULL)
2626  nspname = get_namespace_name(RelationGetNamespace(rel));
2627  if (relname == NULL)
2629 
2630  appendStringInfo(buf, "%s.%s",
2632 }
2633 
2634 /*
2635  * Append a SQL string literal representing "val" to buf.
2636  */
2637 void
2639 {
2640  const char *valptr;
2641 
2642  /*
2643  * Rather than making assumptions about the remote server's value of
2644  * standard_conforming_strings, always use E'foo' syntax if there are any
2645  * backslashes. This will fail on remote servers before 8.1, but those
2646  * are long out of support.
2647  */
2648  if (strchr(val, '\\') != NULL)
2650  appendStringInfoChar(buf, '\'');
2651  for (valptr = val; *valptr; valptr++)
2652  {
2653  char ch = *valptr;
2654 
2655  if (SQL_STR_DOUBLE(ch, true))
2658  }
2659  appendStringInfoChar(buf, '\'');
2660 }
2661 
2662 /*
2663  * Deparse given expression into context->buf.
2664  *
2665  * This function must support all the same node types that foreign_expr_walker
2666  * accepts.
2667  *
2668  * Note: unlike ruleutils.c, we just use a simple hard-wired parenthesization
2669  * scheme: anything more complex than a Var, Const, function call or cast
2670  * should be self-parenthesized.
2671  */
2672 static void
2674 {
2675  if (node == NULL)
2676  return;
2677 
2678  switch (nodeTag(node))
2679  {
2680  case T_Var:
2681  deparseVar((Var *) node, context);
2682  break;
2683  case T_Const:
2684  deparseConst((Const *) node, context, 0);
2685  break;
2686  case T_Param:
2687  deparseParam((Param *) node, context);
2688  break;
2689  case T_SubscriptingRef:
2690  deparseSubscriptingRef((SubscriptingRef *) node, context);
2691  break;
2692  case T_FuncExpr:
2693  deparseFuncExpr((FuncExpr *) node, context);
2694  break;
2695  case T_OpExpr:
2696  deparseOpExpr((OpExpr *) node, context);
2697  break;
2698  case T_DistinctExpr:
2699  deparseDistinctExpr((DistinctExpr *) node, context);
2700  break;
2701  case T_ScalarArrayOpExpr:
2702  deparseScalarArrayOpExpr((ScalarArrayOpExpr *) node, context);
2703  break;
2704  case T_RelabelType:
2705  deparseRelabelType((RelabelType *) node, context);
2706  break;
2707  case T_BoolExpr:
2708  deparseBoolExpr((BoolExpr *) node, context);
2709  break;
2710  case T_NullTest:
2711  deparseNullTest((NullTest *) node, context);
2712  break;
2713  case T_CaseExpr:
2714  deparseCaseExpr((CaseExpr *) node, context);
2715  break;
2716  case T_ArrayExpr:
2717  deparseArrayExpr((ArrayExpr *) node, context);
2718  break;
2719  case T_Aggref:
2720  deparseAggref((Aggref *) node, context);
2721  break;
2722  default:
2723  elog(ERROR, "unsupported expression type for deparse: %d",
2724  (int) nodeTag(node));
2725  break;
2726  }
2727 }
2728 
2729 /*
2730  * Deparse given Var node into context->buf.
2731  *
2732  * If the Var belongs to the foreign relation, just print its remote name.
2733  * Otherwise, it's effectively a Param (and will in fact be a Param at
2734  * run time). Handle it the same way we handle plain Params --- see
2735  * deparseParam for comments.
2736  */
2737 static void
2739 {
2740  Relids relids = context->scanrel->relids;
2741  int relno;
2742  int colno;
2743 
2744  /* Qualify columns when multiple relations are involved. */
2745  bool qualify_col = (bms_membership(relids) == BMS_MULTIPLE);
2746 
2747  /*
2748  * If the Var belongs to the foreign relation that is deparsed as a
2749  * subquery, use the relation and column alias to the Var provided by the
2750  * subquery, instead of the remote name.
2751  */
2752  if (is_subquery_var(node, context->scanrel, &relno, &colno))
2753  {
2754  appendStringInfo(context->buf, "%s%d.%s%d",
2756  SUBQUERY_COL_ALIAS_PREFIX, colno);
2757  return;
2758  }
2759 
2760  if (bms_is_member(node->varno, relids) && node->varlevelsup == 0)
2761  deparseColumnRef(context->buf, node->varno, node->varattno,
2762  planner_rt_fetch(node->varno, context->root),
2763  qualify_col);
2764  else
2765  {
2766  /* Treat like a Param */
2767  if (context->params_list)
2768  {
2769  int pindex = 0;
2770  ListCell *lc;
2771 
2772  /* find its index in params_list */
2773  foreach(lc, *context->params_list)
2774  {
2775  pindex++;
2776  if (equal(node, (Node *) lfirst(lc)))
2777  break;
2778  }
2779  if (lc == NULL)
2780  {
2781  /* not in list, so add it */
2782  pindex++;
2783  *context->params_list = lappend(*context->params_list, node);
2784  }
2785 
2786  printRemoteParam(pindex, node->vartype, node->vartypmod, context);
2787  }
2788  else
2789  {
2790  printRemotePlaceholder(node->vartype, node->vartypmod, context);
2791  }
2792  }
2793 }
2794 
2795 /*
2796  * Deparse given constant value into context->buf.
2797  *
2798  * This function has to be kept in sync with ruleutils.c's get_const_expr.
2799  *
2800  * As in that function, showtype can be -1 to never show "::typename"
2801  * decoration, +1 to always show it, or 0 to show it only if the constant
2802  * wouldn't be assumed to be the right type by default.
2803  *
2804  * In addition, this code allows showtype to be -2 to indicate that we should
2805  * not show "::typename" decoration if the constant is printed as an untyped
2806  * literal or NULL (while in other cases, behaving as for showtype == 0).
2807  */
2808 static void
2809 deparseConst(Const *node, deparse_expr_cxt *context, int showtype)
2810 {
2811  StringInfo buf = context->buf;
2812  Oid typoutput;
2813  bool typIsVarlena;
2814  char *extval;
2815  bool isfloat = false;
2816  bool isstring = false;
2817  bool needlabel;
2818 
2819  if (node->constisnull)
2820  {
2821  appendStringInfoString(buf, "NULL");
2822  if (showtype >= 0)
2823  appendStringInfo(buf, "::%s",
2825  node->consttypmod));
2826  return;
2827  }
2828 
2830  &typoutput, &typIsVarlena);
2831  extval = OidOutputFunctionCall(typoutput, node->constvalue);
2832 
2833  switch (node->consttype)
2834  {
2835  case INT2OID:
2836  case INT4OID:
2837  case INT8OID:
2838  case OIDOID:
2839  case FLOAT4OID:
2840  case FLOAT8OID:
2841  case NUMERICOID:
2842  {
2843  /*
2844  * No need to quote unless it's a special value such as 'NaN'.
2845  * See comments in get_const_expr().
2846  */
2847  if (strspn(extval, "0123456789+-eE.") == strlen(extval))
2848  {
2849  if (extval[0] == '+' || extval[0] == '-')
2850  appendStringInfo(buf, "(%s)", extval);
2851  else
2852  appendStringInfoString(buf, extval);
2853  if (strcspn(extval, "eE.") != strlen(extval))
2854  isfloat = true; /* it looks like a float */
2855  }
2856  else
2857  appendStringInfo(buf, "'%s'", extval);
2858  }
2859  break;
2860  case BITOID:
2861  case VARBITOID:
2862  appendStringInfo(buf, "B'%s'", extval);
2863  break;
2864  case BOOLOID:
2865  if (strcmp(extval, "t") == 0)
2866  appendStringInfoString(buf, "true");
2867  else
2868  appendStringInfoString(buf, "false");
2869  break;
2870  default:
2871  deparseStringLiteral(buf, extval);
2872  isstring = true;
2873  break;
2874  }
2875 
2876  pfree(extval);
2877 
2878  if (showtype == -1)
2879  return; /* never print type label */
2880 
2881  /*
2882  * For showtype == 0, append ::typename unless the constant will be
2883  * implicitly typed as the right type when it is read in.
2884  *
2885  * XXX this code has to be kept in sync with the behavior of the parser,
2886  * especially make_const.
2887  */
2888  switch (node->consttype)
2889  {
2890  case BOOLOID:
2891  case INT4OID:
2892  case UNKNOWNOID:
2893  needlabel = false;
2894  break;
2895  case NUMERICOID:
2896  needlabel = !isfloat || (node->consttypmod >= 0);
2897  break;
2898  default:
2899  if (showtype == -2)
2900  {
2901  /* label unless we printed it as an untyped string */
2902  needlabel = !isstring;
2903  }
2904  else
2905  needlabel = true;
2906  break;
2907  }
2908  if (needlabel || showtype > 0)
2909  appendStringInfo(buf, "::%s",
2911  node->consttypmod));
2912 }
2913 
2914 /*
2915  * Deparse given Param node.
2916  *
2917  * If we're generating the query "for real", add the Param to
2918  * context->params_list if it's not already present, and then use its index
2919  * in that list as the remote parameter number. During EXPLAIN, there's
2920  * no need to identify a parameter number.
2921  */
2922 static void
2924 {
2925  if (context->params_list)
2926  {
2927  int pindex = 0;
2928  ListCell *lc;
2929 
2930  /* find its index in params_list */
2931  foreach(lc, *context->params_list)
2932  {
2933  pindex++;
2934  if (equal(node, (Node *) lfirst(lc)))
2935  break;
2936  }
2937  if (lc == NULL)
2938  {
2939  /* not in list, so add it */
2940  pindex++;
2941  *context->params_list = lappend(*context->params_list, node);
2942  }
2943 
2944  printRemoteParam(pindex, node->paramtype, node->paramtypmod, context);
2945  }
2946  else
2947  {
2948  printRemotePlaceholder(node->paramtype, node->paramtypmod, context);
2949  }
2950 }
2951 
2952 /*
2953  * Deparse a container subscript expression.
2954  */
2955 static void
2957 {
2958  StringInfo buf = context->buf;
2959  ListCell *lowlist_item;
2960  ListCell *uplist_item;
2961 
2962  /* Always parenthesize the expression. */
2963  appendStringInfoChar(buf, '(');
2964 
2965  /*
2966  * Deparse referenced array expression first. If that expression includes
2967  * a cast, we have to parenthesize to prevent the array subscript from
2968  * being taken as typename decoration. We can avoid that in the typical
2969  * case of subscripting a Var, but otherwise do it.
2970  */
2971  if (IsA(node->refexpr, Var))
2972  deparseExpr(node->refexpr, context);
2973  else
2974  {
2975  appendStringInfoChar(buf, '(');
2976  deparseExpr(node->refexpr, context);
2977  appendStringInfoChar(buf, ')');
2978  }
2979 
2980  /* Deparse subscript expressions. */
2981  lowlist_item = list_head(node->reflowerindexpr); /* could be NULL */
2982  foreach(uplist_item, node->refupperindexpr)
2983  {
2984  appendStringInfoChar(buf, '[');
2985  if (lowlist_item)
2986  {
2987  deparseExpr(lfirst(lowlist_item), context);
2988  appendStringInfoChar(buf, ':');
2989  lowlist_item = lnext(node->reflowerindexpr, lowlist_item);
2990  }
2991  deparseExpr(lfirst(uplist_item), context);
2992  appendStringInfoChar(buf, ']');
2993  }
2994 
2995  appendStringInfoChar(buf, ')');
2996 }
2997 
2998 /*
2999  * Deparse a function call.
3000  */
3001 static void
3003 {
3004  StringInfo buf = context->buf;
3005  bool use_variadic;
3006  bool first;
3007  ListCell *arg;
3008 
3009  /*
3010  * If the function call came from an implicit coercion, then just show the
3011  * first argument.
3012  */
3013  if (node->funcformat == COERCE_IMPLICIT_CAST)
3014  {
3015  deparseExpr((Expr *) linitial(node->args), context);
3016  return;
3017  }
3018 
3019  /*
3020  * If the function call came from a cast, then show the first argument
3021  * plus an explicit cast operation.
3022  */
3023  if (node->funcformat == COERCE_EXPLICIT_CAST)
3024  {
3025  Oid rettype = node->funcresulttype;
3026  int32 coercedTypmod;
3027 
3028  /* Get the typmod if this is a length-coercion function */
3029  (void) exprIsLengthCoercion((Node *) node, &coercedTypmod);
3030 
3031  deparseExpr((Expr *) linitial(node->args), context);
3032  appendStringInfo(buf, "::%s",
3033  deparse_type_name(rettype, coercedTypmod));
3034  return;
3035  }
3036 
3037  /* Check if need to print VARIADIC (cf. ruleutils.c) */
3038  use_variadic = node->funcvariadic;
3039 
3040  /*
3041  * Normal function: display as proname(args).
3042  */
3043  appendFunctionName(node->funcid, context);
3044  appendStringInfoChar(buf, '(');
3045 
3046  /* ... and all the arguments */
3047  first = true;
3048  foreach(arg, node->args)
3049  {
3050  if (!first)
3051  appendStringInfoString(buf, ", ");
3052  if (use_variadic && lnext(node->args, arg) == NULL)
3053  appendStringInfoString(buf, "VARIADIC ");
3054  deparseExpr((Expr *) lfirst(arg), context);
3055  first = false;
3056  }
3057  appendStringInfoChar(buf, ')');
3058 }
3059 
3060 /*
3061  * Deparse given operator expression. To avoid problems around
3062  * priority of operations, we always parenthesize the arguments.
3063  */
3064 static void
3066 {
3067  StringInfo buf = context->buf;
3068  HeapTuple tuple;
3069  Form_pg_operator form;
3070  Expr *right;
3071  bool canSuppressRightConstCast = false;
3072  char oprkind;
3073 
3074  /* Retrieve information about the operator from system catalog. */
3075  tuple = SearchSysCache1(OPEROID, ObjectIdGetDatum(node->opno));
3076  if (!HeapTupleIsValid(tuple))
3077  elog(ERROR, "cache lookup failed for operator %u", node->opno);
3078  form = (Form_pg_operator) GETSTRUCT(tuple);
3079  oprkind = form->oprkind;
3080 
3081  /* Sanity check. */
3082  Assert((oprkind == 'l' && list_length(node->args) == 1) ||
3083  (oprkind == 'b' && list_length(node->args) == 2));
3084 
3085  right = llast(node->args);
3086 
3087  /* Always parenthesize the expression. */
3088  appendStringInfoChar(buf, '(');
3089 
3090  /* Deparse left operand, if any. */
3091  if (oprkind == 'b')
3092  {
3093  Expr *left = linitial(node->args);
3094  Oid leftType = exprType((Node *) left);
3095  Oid rightType = exprType((Node *) right);
3096  bool canSuppressLeftConstCast = false;
3097 
3098  /*
3099  * When considering a binary operator, if one operand is a Const that
3100  * can be printed as a bare string literal or NULL (i.e., it will look
3101  * like type UNKNOWN to the remote parser), the Const normally
3102  * receives an explicit cast to the operator's input type. However,
3103  * in Const-to-Var comparisons where both operands are of the same
3104  * type, we prefer to suppress the explicit cast, leaving the Const's
3105  * type resolution up to the remote parser. The remote's resolution
3106  * heuristic will assume that an unknown input type being compared to
3107  * a known input type is of that known type as well.
3108  *
3109  * This hack allows some cases to succeed where a remote column is
3110  * declared with a different type in the local (foreign) table. By
3111  * emitting "foreigncol = 'foo'" not "foreigncol = 'foo'::text" or the
3112  * like, we allow the remote parser to pick an "=" operator that's
3113  * compatible with whatever type the remote column really is, such as
3114  * an enum.
3115  *
3116  * We allow cast suppression to happen only when the other operand is
3117  * a plain foreign Var. Although the remote's unknown-type heuristic
3118  * would apply to other cases just as well, we would be taking a
3119  * bigger risk that the inferred type is something unexpected. With
3120  * this restriction, if anything goes wrong it's the user's fault for
3121  * not declaring the local column with the same type as the remote
3122  * column.
3123  */
3124  if (leftType == rightType)
3125  {
3126  if (IsA(left, Const))
3127  canSuppressLeftConstCast = isPlainForeignVar(right, context);
3128  else if (IsA(right, Const))
3129  canSuppressRightConstCast = isPlainForeignVar(left, context);
3130  }
3131 
3132  if (canSuppressLeftConstCast)
3133  deparseConst((Const *) left, context, -2);
3134  else
3135  deparseExpr(left, context);
3136 
3137  appendStringInfoChar(buf, ' ');
3138  }
3139 
3140  /* Deparse operator name. */
3141  deparseOperatorName(buf, form);
3142 
3143  /* Deparse right operand. */
3144  appendStringInfoChar(buf, ' ');
3145 
3146  if (canSuppressRightConstCast)
3147  deparseConst((Const *) right, context, -2);
3148  else
3149  deparseExpr(right, context);
3150 
3151  appendStringInfoChar(buf, ')');
3152 
3153  ReleaseSysCache(tuple);
3154 }
3155 
3156 /*
3157  * Will "node" deparse as a plain foreign Var?
3158  */
3159 static bool
3161 {
3162  /*
3163  * We allow the foreign Var to have an implicit RelabelType, mainly so
3164  * that this'll work with varchar columns. Note that deparseRelabelType
3165  * will not print such a cast, so we're not breaking the restriction that
3166  * the expression print as a plain Var. We won't risk it for an implicit
3167  * cast that requires a function, nor for non-implicit RelabelType; such
3168  * cases seem too likely to involve semantics changes compared to what
3169  * would happen on the remote side.
3170  */
3171  if (IsA(node, RelabelType) &&
3172  ((RelabelType *) node)->relabelformat == COERCE_IMPLICIT_CAST)
3173  node = ((RelabelType *) node)->arg;
3174 
3175  if (IsA(node, Var))
3176  {
3177  /*
3178  * The Var must be one that'll deparse as a foreign column reference
3179  * (cf. deparseVar).
3180  */
3181  Var *var = (Var *) node;
3182  Relids relids = context->scanrel->relids;
3183 
3184  if (bms_is_member(var->varno, relids) && var->varlevelsup == 0)
3185  return true;
3186  }
3187 
3188  return false;
3189 }
3190 
3191 /*
3192  * Print the name of an operator.
3193  */
3194 static void
3196 {
3197  char *opname;
3198 
3199  /* opname is not a SQL identifier, so we should not quote it. */
3200  opname = NameStr(opform->oprname);
3201 
3202  /* Print schema name only if it's not pg_catalog */
3203  if (opform->oprnamespace != PG_CATALOG_NAMESPACE)
3204  {
3205  const char *opnspname;
3206 
3207  opnspname = get_namespace_name(opform->oprnamespace);
3208  /* Print fully qualified operator name. */
3209  appendStringInfo(buf, "OPERATOR(%s.%s)",
3210  quote_identifier(opnspname), opname);
3211  }
3212  else
3213  {
3214  /* Just print operator name. */
3215  appendStringInfoString(buf, opname);
3216  }
3217 }
3218 
3219 /*
3220  * Deparse IS DISTINCT FROM.
3221  */
3222 static void
3224 {
3225  StringInfo buf = context->buf;
3226 
3227  Assert(list_length(node->args) == 2);
3228 
3229  appendStringInfoChar(buf, '(');
3230  deparseExpr(linitial(node->args), context);
3231  appendStringInfoString(buf, " IS DISTINCT FROM ");
3232  deparseExpr(lsecond(node->args), context);
3233  appendStringInfoChar(buf, ')');
3234 }
3235 
3236 /*
3237  * Deparse given ScalarArrayOpExpr expression. To avoid problems
3238  * around priority of operations, we always parenthesize the arguments.
3239  */
3240 static void
3242 {
3243  StringInfo buf = context->buf;
3244  HeapTuple tuple;
3245  Form_pg_operator form;
3246  Expr *arg1;
3247  Expr *arg2;
3248 
3249  /* Retrieve information about the operator from system catalog. */
3250  tuple = SearchSysCache1(OPEROID, ObjectIdGetDatum(node->opno));
3251  if (!HeapTupleIsValid(tuple))
3252  elog(ERROR, "cache lookup failed for operator %u", node->opno);
3253  form = (Form_pg_operator) GETSTRUCT(tuple);
3254 
3255  /* Sanity check. */
3256  Assert(list_length(node->args) == 2);
3257 
3258  /* Always parenthesize the expression. */
3259  appendStringInfoChar(buf, '(');
3260 
3261  /* Deparse left operand. */
3262  arg1 = linitial(node->args);
3263  deparseExpr(arg1, context);
3264  appendStringInfoChar(buf, ' ');
3265 
3266  /* Deparse operator name plus decoration. */
3267  deparseOperatorName(buf, form);
3268  appendStringInfo(buf, " %s (", node->useOr ? "ANY" : "ALL");
3269 
3270  /* Deparse right operand. */
3271  arg2 = lsecond(node->args);
3272  deparseExpr(arg2, context);
3273 
3274  appendStringInfoChar(buf, ')');
3275 
3276  /* Always parenthesize the expression. */
3277  appendStringInfoChar(buf, ')');
3278 
3279  ReleaseSysCache(tuple);
3280 }
3281 
3282 /*
3283  * Deparse a RelabelType (binary-compatible cast) node.
3284  */
3285 static void
3287 {
3288  deparseExpr(node->arg, context);
3289  if (node->relabelformat != COERCE_IMPLICIT_CAST)
3290  appendStringInfo(context->buf, "::%s",
3292  node->resulttypmod));
3293 }
3294 
3295 /*
3296  * Deparse a BoolExpr node.
3297  */
3298 static void
3300 {
3301  StringInfo buf = context->buf;
3302  const char *op = NULL; /* keep compiler quiet */
3303  bool first;
3304  ListCell *lc;
3305 
3306  switch (node->boolop)
3307  {
3308  case AND_EXPR:
3309  op = "AND";
3310  break;
3311  case OR_EXPR:
3312  op = "OR";
3313  break;
3314  case NOT_EXPR:
3315  appendStringInfoString(buf, "(NOT ");
3316  deparseExpr(linitial(node->args), context);
3317  appendStringInfoChar(buf, ')');
3318  return;
3319  }
3320 
3321  appendStringInfoChar(buf, '(');
3322  first = true;
3323  foreach(lc, node->args)
3324  {
3325  if (!first)
3326  appendStringInfo(buf, " %s ", op);
3327  deparseExpr((Expr *) lfirst(lc), context);
3328  first = false;
3329  }
3330  appendStringInfoChar(buf, ')');
3331 }
3332 
3333 /*
3334  * Deparse IS [NOT] NULL expression.
3335  */
3336 static void
3338 {
3339  StringInfo buf = context->buf;
3340 
3341  appendStringInfoChar(buf, '(');
3342  deparseExpr(node->arg, context);
3343 
3344  /*
3345  * For scalar inputs, we prefer to print as IS [NOT] NULL, which is
3346  * shorter and traditional. If it's a rowtype input but we're applying a
3347  * scalar test, must print IS [NOT] DISTINCT FROM NULL to be semantically
3348  * correct.
3349  */
3350  if (node->argisrow || !type_is_rowtype(exprType((Node *) node->arg)))
3351  {
3352  if (node->nulltesttype == IS_NULL)
3353  appendStringInfoString(buf, " IS NULL)");
3354  else
3355  appendStringInfoString(buf, " IS NOT NULL)");
3356  }
3357  else
3358  {
3359  if (node->nulltesttype == IS_NULL)
3360  appendStringInfoString(buf, " IS NOT DISTINCT FROM NULL)");
3361  else
3362  appendStringInfoString(buf, " IS DISTINCT FROM NULL)");
3363  }
3364 }
3365 
3366 /*
3367  * Deparse CASE expression
3368  */
3369 static void
3371 {
3372  StringInfo buf = context->buf;
3373  ListCell *lc;
3374 
3375  appendStringInfoString(buf, "(CASE");
3376 
3377  /* If this is a CASE arg WHEN then emit the arg expression */
3378  if (node->arg != NULL)
3379  {
3380  appendStringInfoChar(buf, ' ');
3381  deparseExpr(node->arg, context);
3382  }
3383 
3384  /* Add each condition/result of the CASE clause */
3385  foreach(lc, node->args)
3386  {
3387  CaseWhen *whenclause = (CaseWhen *) lfirst(lc);
3388 
3389  /* WHEN */
3390  appendStringInfoString(buf, " WHEN ");
3391  if (node->arg == NULL) /* CASE WHEN */
3392  deparseExpr(whenclause->expr, context);
3393  else /* CASE arg WHEN */
3394  {
3395  /* Ignore the CaseTestExpr and equality operator. */
3396  deparseExpr(lsecond(castNode(OpExpr, whenclause->expr)->args),
3397  context);
3398  }
3399 
3400  /* THEN */
3401  appendStringInfoString(buf, " THEN ");
3402  deparseExpr(whenclause->result, context);
3403  }
3404 
3405  /* add ELSE if present */
3406  if (node->defresult != NULL)
3407  {
3408  appendStringInfoString(buf, " ELSE ");
3409  deparseExpr(node->defresult, context);
3410  }
3411 
3412  /* append END */
3413  appendStringInfoString(buf, " END)");
3414 }
3415 
3416 /*
3417  * Deparse ARRAY[...] construct.
3418  */
3419 static void
3421 {
3422  StringInfo buf = context->buf;
3423  bool first = true;
3424  ListCell *lc;
3425 
3426  appendStringInfoString(buf, "ARRAY[");
3427  foreach(lc, node->elements)
3428  {
3429  if (!first)
3430  appendStringInfoString(buf, ", ");
3431  deparseExpr(lfirst(lc), context);
3432  first = false;
3433  }
3434  appendStringInfoChar(buf, ']');
3435 
3436  /* If the array is empty, we need an explicit cast to the array type. */
3437  if (node->elements == NIL)
3438  appendStringInfo(buf, "::%s",
3439  deparse_type_name(node->array_typeid, -1));
3440 }
3441 
3442 /*
3443  * Deparse an Aggref node.
3444  */
3445 static void
3447 {
3448  StringInfo buf = context->buf;
3449  bool use_variadic;
3450 
3451  /* Only basic, non-split aggregation accepted. */
3452  Assert(node->aggsplit == AGGSPLIT_SIMPLE);
3453 
3454  /* Check if need to print VARIADIC (cf. ruleutils.c) */
3455  use_variadic = node->aggvariadic;
3456 
3457  /* Find aggregate name from aggfnoid which is a pg_proc entry */
3458  appendFunctionName(node->aggfnoid, context);
3459  appendStringInfoChar(buf, '(');
3460 
3461  /* Add DISTINCT */
3462  appendStringInfoString(buf, (node->aggdistinct != NIL) ? "DISTINCT " : "");
3463 
3464  if (AGGKIND_IS_ORDERED_SET(node->aggkind))
3465  {
3466  /* Add WITHIN GROUP (ORDER BY ..) */
3467  ListCell *arg;
3468  bool first = true;
3469 
3470  Assert(!node->aggvariadic);
3471  Assert(node->aggorder != NIL);
3472 
3473  foreach(arg, node->aggdirectargs)
3474  {
3475  if (!first)
3476  appendStringInfoString(buf, ", ");
3477  first = false;
3478 
3479  deparseExpr((Expr *) lfirst(arg), context);
3480  }
3481 
3482  appendStringInfoString(buf, ") WITHIN GROUP (ORDER BY ");
3483  appendAggOrderBy(node->aggorder, node->args, context);
3484  }
3485  else
3486  {
3487  /* aggstar can be set only in zero-argument aggregates */
3488  if (node->aggstar)
3489  appendStringInfoChar(buf, '*');
3490  else
3491  {
3492  ListCell *arg;
3493  bool first = true;
3494 
3495  /* Add all the arguments */
3496  foreach(arg, node->args)
3497  {
3498  TargetEntry *tle = (TargetEntry *) lfirst(arg);
3499  Node *n = (Node *) tle->expr;
3500 
3501  if (tle->resjunk)
3502  continue;
3503 
3504  if (!first)
3505  appendStringInfoString(buf, ", ");
3506  first = false;
3507 
3508  /* Add VARIADIC */
3509  if (use_variadic && lnext(node->args, arg) == NULL)
3510  appendStringInfoString(buf, "VARIADIC ");
3511 
3512  deparseExpr((Expr *) n, context);
3513  }
3514  }
3515 
3516  /* Add ORDER BY */
3517  if (node->aggorder != NIL)
3518  {
3519  appendStringInfoString(buf, " ORDER BY ");
3520  appendAggOrderBy(node->aggorder, node->args, context);
3521  }
3522  }
3523 
3524  /* Add FILTER (WHERE ..) */
3525  if (node->aggfilter != NULL)
3526  {
3527  appendStringInfoString(buf, ") FILTER (WHERE ");
3528  deparseExpr((Expr *) node->aggfilter, context);
3529  }
3530 
3531  appendStringInfoChar(buf, ')');
3532 }
3533 
3534 /*
3535  * Append ORDER BY within aggregate function.
3536  */
3537 static void
3538 appendAggOrderBy(List *orderList, List *targetList, deparse_expr_cxt *context)
3539 {
3540  StringInfo buf = context->buf;
3541  ListCell *lc;
3542  bool first = true;
3543 
3544  foreach(lc, orderList)
3545  {
3546  SortGroupClause *srt = (SortGroupClause *) lfirst(lc);
3547  Node *sortexpr;
3548 
3549  if (!first)
3550  appendStringInfoString(buf, ", ");
3551  first = false;
3552 
3553  /* Deparse the sort expression proper. */
3554  sortexpr = deparseSortGroupClause(srt->tleSortGroupRef, targetList,
3555  false, context);
3556  /* Add decoration as needed. */
3557  appendOrderBySuffix(srt->sortop, exprType(sortexpr), srt->nulls_first,
3558  context);
3559  }
3560 }
3561 
3562 /*
3563  * Append the ASC, DESC, USING <OPERATOR> and NULLS FIRST / NULLS LAST parts
3564  * of an ORDER BY clause.
3565  */
3566 static void
3567 appendOrderBySuffix(Oid sortop, Oid sortcoltype, bool nulls_first,
3568  deparse_expr_cxt *context)
3569 {
3570  StringInfo buf = context->buf;
3571  TypeCacheEntry *typentry;
3572 
3573  /* See whether operator is default < or > for sort expr's datatype. */
3574  typentry = lookup_type_cache(sortcoltype,
3576 
3577  if (sortop == typentry->lt_opr)
3578  appendStringInfoString(buf, " ASC");
3579  else if (sortop == typentry->gt_opr)
3580  appendStringInfoString(buf, " DESC");
3581  else
3582  {
3583  HeapTuple opertup;
3584  Form_pg_operator operform;
3585 
3586  appendStringInfoString(buf, " USING ");
3587 
3588  /* Append operator name. */
3589  opertup = SearchSysCache1(OPEROID, ObjectIdGetDatum(sortop));
3590  if (!HeapTupleIsValid(opertup))
3591  elog(ERROR, "cache lookup failed for operator %u", sortop);
3592  operform = (Form_pg_operator) GETSTRUCT(opertup);
3593  deparseOperatorName(buf, operform);
3594  ReleaseSysCache(opertup);
3595  }
3596 
3597  if (nulls_first)
3598  appendStringInfoString(buf, " NULLS FIRST");
3599  else
3600  appendStringInfoString(buf, " NULLS LAST");
3601 }
3602 
3603 /*
3604  * Print the representation of a parameter to be sent to the remote side.
3605  *
3606  * Note: we always label the Param's type explicitly rather than relying on
3607  * transmitting a numeric type OID in PQexecParams(). This allows us to
3608  * avoid assuming that types have the same OIDs on the remote side as they
3609  * do locally --- they need only have the same names.
3610  */
3611 static void
3612 printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod,
3613  deparse_expr_cxt *context)
3614 {
3615  StringInfo buf = context->buf;
3616  char *ptypename = deparse_type_name(paramtype, paramtypmod);
3617 
3618  appendStringInfo(buf, "$%d::%s", paramindex, ptypename);
3619 }
3620 
3621 /*
3622  * Print the representation of a placeholder for a parameter that will be
3623  * sent to the remote side at execution time.
3624  *
3625  * This is used when we're just trying to EXPLAIN the remote query.
3626  * We don't have the actual value of the runtime parameter yet, and we don't
3627  * want the remote planner to generate a plan that depends on such a value
3628  * anyway. Thus, we can't do something simple like "$1::paramtype".
3629  * Instead, we emit "((SELECT null::paramtype)::paramtype)".
3630  * In all extant versions of Postgres, the planner will see that as an unknown
3631  * constant value, which is what we want. This might need adjustment if we
3632  * ever make the planner flatten scalar subqueries. Note: the reason for the
3633  * apparently useless outer cast is to ensure that the representation as a
3634  * whole will be parsed as an a_expr and not a select_with_parens; the latter
3635  * would do the wrong thing in the context "x = ANY(...)".
3636  */
3637 static void
3638 printRemotePlaceholder(Oid paramtype, int32 paramtypmod,
3639  deparse_expr_cxt *context)
3640 {
3641  StringInfo buf = context->buf;
3642  char *ptypename = deparse_type_name(paramtype, paramtypmod);
3643 
3644  appendStringInfo(buf, "((SELECT null::%s)::%s)", ptypename, ptypename);
3645 }
3646 
3647 /*
3648  * Deparse GROUP BY clause.
3649  */
3650 static void
3652 {
3653  StringInfo buf = context->buf;
3654  Query *query = context->root->parse;
3655  ListCell *lc;
3656  bool first = true;
3657 
3658  /* Nothing to be done, if there's no GROUP BY clause in the query. */
3659  if (!query->groupClause)
3660  return;
3661 
3662  appendStringInfoString(buf, " GROUP BY ");
3663 
3664  /*
3665  * Queries with grouping sets are not pushed down, so we don't expect
3666  * grouping sets here.
3667  */
3668  Assert(!query->groupingSets);
3669 
3670  foreach(lc, query->groupClause)
3671  {
3672  SortGroupClause *grp = (SortGroupClause *) lfirst(lc);
3673 
3674  if (!first)
3675  appendStringInfoString(buf, ", ");
3676  first = false;
3677 
3678  deparseSortGroupClause(grp->tleSortGroupRef, tlist, true, context);
3679  }
3680 }
3681 
3682 /*
3683  * Deparse ORDER BY clause defined by the given pathkeys.
3684  *
3685  * The clause should use Vars from context->scanrel if !has_final_sort,
3686  * or from context->foreignrel's targetlist if has_final_sort.
3687  *
3688  * We find a suitable pathkey expression (some earlier step
3689  * should have verified that there is one) and deparse it.
3690  */
3691 static void
3692 appendOrderByClause(List *pathkeys, bool has_final_sort,
3693  deparse_expr_cxt *context)
3694 {
3695  ListCell *lcell;
3696  int nestlevel;
3697  const char *delim = " ";
3698  StringInfo buf = context->buf;
3699 
3700  /* Make sure any constants in the exprs are printed portably */
3701  nestlevel = set_transmission_modes();
3702 
3703  appendStringInfoString(buf, " ORDER BY");
3704  foreach(lcell, pathkeys)
3705  {
3706  PathKey *pathkey = lfirst(lcell);
3707  EquivalenceMember *em;
3708  Expr *em_expr;
3709  Oid oprid;
3710 
3711  if (has_final_sort)
3712  {
3713  /*
3714  * By construction, context->foreignrel is the input relation to
3715  * the final sort.
3716  */
3717  em = find_em_for_rel_target(context->root,
3718  pathkey->pk_eclass,
3719  context->foreignrel);
3720  }
3721  else
3722  em = find_em_for_rel(context->root,
3723  pathkey->pk_eclass,
3724  context->scanrel);
3725 
3726  /*
3727  * We don't expect any error here; it would mean that shippability
3728  * wasn't verified earlier. For the same reason, we don't recheck
3729  * shippability of the sort operator.
3730  */
3731  if (em == NULL)
3732  elog(ERROR, "could not find pathkey item to sort");
3733 
3734  em_expr = em->em_expr;
3735 
3736  /*
3737  * Lookup the operator corresponding to the strategy in the opclass.
3738  * The datatype used by the opfamily is not necessarily the same as
3739  * the expression type (for array types for example).
3740  */
3742  em->em_datatype,
3743  em->em_datatype,
3744  pathkey->pk_strategy);
3745  if (!OidIsValid(oprid))
3746  elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
3747  pathkey->pk_strategy, em->em_datatype, em->em_datatype,
3748  pathkey->pk_opfamily);
3749 
3750  appendStringInfoString(buf, delim);
3751  deparseExpr(em_expr, context);
3752 
3753  /*
3754  * Here we need to use the expression's actual type to discover
3755  * whether the desired operator will be the default or not.
3756  */
3757  appendOrderBySuffix(oprid, exprType((Node *) em_expr),
3758  pathkey->pk_nulls_first, context);
3759 
3760  delim = ", ";
3761  }
3762  reset_transmission_modes(nestlevel);
3763 }
3764 
3765 /*
3766  * Deparse LIMIT/OFFSET clause.
3767  */
3768 static void
3770 {
3771  PlannerInfo *root = context->root;
3772  StringInfo buf = context->buf;
3773  int nestlevel;
3774 
3775  /* Make sure any constants in the exprs are printed portably */
3776  nestlevel = set_transmission_modes();
3777 
3778  if (root->parse->limitCount)
3779  {
3780  appendStringInfoString(buf, " LIMIT ");
3781  deparseExpr((Expr *) root->parse->limitCount, context);
3782  }
3783  if (root->parse->limitOffset)
3784  {
3785  appendStringInfoString(buf, " OFFSET ");
3786  deparseExpr((Expr *) root->parse->limitOffset, context);
3787  }
3788 
3789  reset_transmission_modes(nestlevel);
3790 }
3791 
3792 /*
3793  * appendFunctionName
3794  * Deparses function name from given function oid.
3795  */
3796 static void
3798 {
3799  StringInfo buf = context->buf;
3800  HeapTuple proctup;
3801  Form_pg_proc procform;
3802  const char *proname;
3803 
3804  proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
3805  if (!HeapTupleIsValid(proctup))
3806  elog(ERROR, "cache lookup failed for function %u", funcid);
3807  procform = (Form_pg_proc) GETSTRUCT(proctup);
3808 
3809  /* Print schema name only if it's not pg_catalog */
3810  if (procform->pronamespace != PG_CATALOG_NAMESPACE)
3811  {
3812  const char *schemaname;
3813 
3814  schemaname = get_namespace_name(procform->pronamespace);
3815  appendStringInfo(buf, "%s.", quote_identifier(schemaname));
3816  }
3817 
3818  /* Always print the function name */
3819  proname = NameStr(procform->proname);
3821 
3822  ReleaseSysCache(proctup);
3823 }
3824 
3825 /*
3826  * Appends a sort or group clause.
3827  *
3828  * Like get_rule_sortgroupclause(), returns the expression tree, so caller
3829  * need not find it again.
3830  */
3831 static Node *
3832 deparseSortGroupClause(Index ref, List *tlist, bool force_colno,
3833  deparse_expr_cxt *context)
3834 {
3835  StringInfo buf = context->buf;
3836  TargetEntry *tle;
3837  Expr *expr;
3838 
3839  tle = get_sortgroupref_tle(ref, tlist);
3840  expr = tle->expr;
3841 
3842  if (force_colno)
3843  {
3844  /* Use column-number form when requested by caller. */
3845  Assert(!tle->resjunk);
3846  appendStringInfo(buf, "%d", tle->resno);
3847  }
3848  else if (expr && IsA(expr, Const))
3849  {
3850  /*
3851  * Force a typecast here so that we don't emit something like "GROUP
3852  * BY 2", which will be misconstrued as a column position rather than
3853  * a constant.
3854  */
3855  deparseConst((Const *) expr, context, 1);
3856  }
3857  else if (!expr || IsA(expr, Var))
3858  deparseExpr(expr, context);
3859  else
3860  {
3861  /* Always parenthesize the expression. */
3862  appendStringInfoChar(buf, '(');
3863  deparseExpr(expr, context);
3864  appendStringInfoChar(buf, ')');
3865  }
3866 
3867  return (Node *) expr;
3868 }
3869 
3870 
3871 /*
3872  * Returns true if given Var is deparsed as a subquery output column, in
3873  * which case, *relno and *colno are set to the IDs for the relation and
3874  * column alias to the Var provided by the subquery.
3875  */
3876 static bool
3877 is_subquery_var(Var *node, RelOptInfo *foreignrel, int *relno, int *colno)
3878 {
3879  PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
3880  RelOptInfo *outerrel = fpinfo->outerrel;
3881  RelOptInfo *innerrel = fpinfo->innerrel;
3882 
3883  /* Should only be called in these cases. */
3884  Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
3885 
3886  /*
3887  * If the given relation isn't a join relation, it doesn't have any lower
3888  * subqueries, so the Var isn't a subquery output column.
3889  */
3890  if (!IS_JOIN_REL(foreignrel))
3891  return false;
3892 
3893  /*
3894  * If the Var doesn't belong to any lower subqueries, it isn't a subquery
3895  * output column.
3896  */
3897  if (!bms_is_member(node->varno, fpinfo->lower_subquery_rels))
3898  return false;
3899 
3900  if (bms_is_member(node->varno, outerrel->relids))
3901  {
3902  /*
3903  * If outer relation is deparsed as a subquery, the Var is an output
3904  * column of the subquery; get the IDs for the relation/column alias.
3905  */
3906  if (fpinfo->make_outerrel_subquery)
3907  {
3908  get_relation_column_alias_ids(node, outerrel, relno, colno);
3909  return true;
3910  }
3911 
3912  /* Otherwise, recurse into the outer relation. */
3913  return is_subquery_var(node, outerrel, relno, colno);
3914  }
3915  else
3916  {
3917  Assert(bms_is_member(node->varno, innerrel->relids));
3918 
3919  /*
3920  * If inner relation is deparsed as a subquery, the Var is an output
3921  * column of the subquery; get the IDs for the relation/column alias.
3922  */
3923  if (fpinfo->make_innerrel_subquery)
3924  {
3925  get_relation_column_alias_ids(node, innerrel, relno, colno);
3926  return true;
3927  }
3928 
3929  /* Otherwise, recurse into the inner relation. */
3930  return is_subquery_var(node, innerrel, relno, colno);
3931  }
3932 }
3933 
3934 /*
3935  * Get the IDs for the relation and column alias to given Var belonging to
3936  * given relation, which are returned into *relno and *colno.
3937  */
3938 static void
3940  int *relno, int *colno)
3941 {
3942  PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
3943  int i;
3944  ListCell *lc;
3945 
3946  /* Get the relation alias ID */
3947  *relno = fpinfo->relation_index;
3948 
3949  /* Get the column alias ID */
3950  i = 1;
3951  foreach(lc, foreignrel->reltarget->exprs)
3952  {
3953  if (equal(lfirst(lc), (Node *) node))
3954  {
3955  *colno = i;
3956  return;
3957  }
3958  i++;
3959  }
3960 
3961  /* Shouldn't get here */
3962  elog(ERROR, "unexpected expression in subquery output");
3963 }
int16 AttrNumber
Definition: attnum.h:21
int bms_next_member(const Bitmapset *a, int prevbit)
Definition: bitmapset.c:1047
void bms_free(Bitmapset *a)
Definition: bitmapset.c:209
bool bms_is_member(int x, const Bitmapset *a)
Definition: bitmapset.c:428
Bitmapset * bms_make_singleton(int x)
Definition: bitmapset.c:186
Bitmapset * bms_add_member(Bitmapset *a, int x)
Definition: bitmapset.c:739
BMS_Membership bms_membership(const Bitmapset *a)
Definition: bitmapset.c:675
@ BMS_MULTIPLE
Definition: bitmapset.h:75
#define FORMAT_TYPE_TYPEMOD_GIVEN
Definition: builtins.h:112
#define FORMAT_TYPE_FORCE_QUALIFY
Definition: builtins.h:114
#define NameStr(name)
Definition: c.h:682
uint16 bits16
Definition: c.h:450
signed int int32
Definition: c.h:430
#define ESCAPE_STRING_SYNTAX
Definition: c.h:1105
#define SQL_STR_DOUBLE(ch, escape_backslash)
Definition: c.h:1102
unsigned int Index
Definition: c.h:550
#define OidIsValid(objectId)
Definition: c.h:711
bool contain_mutable_functions(Node *clause)
Definition: clauses.c:365
char * defGetString(DefElem *def)
Definition: define.c:49
static void deparseCaseExpr(CaseExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3370
void deparseAnalyzeSizeSql(StringInfo buf, Relation rel)
Definition: deparse.c:2357
static void deparseBoolExpr(BoolExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3299
static void appendGroupByClause(List *tlist, deparse_expr_cxt *context)
Definition: deparse.c:3651
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
static void deparseRangeTblRef(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel, bool make_subquery, Index ignore_rel, List **ignore_conds, List **params_list)
Definition: deparse.c:1868
#define SUBQUERY_REL_ALIAS_PREFIX
Definition: deparse.c:114
static void deparseFromExpr(List *quals, deparse_expr_cxt *context)
Definition: deparse.c:1369
static Node * deparseSortGroupClause(Index ref, List *tlist, bool force_colno, deparse_expr_cxt *context)
Definition: deparse.c:3832
static void deparseLockingClause(deparse_expr_cxt *context)
Definition: deparse.c:1479
const char * get_jointype_name(JoinType jointype)
Definition: deparse.c:1603
static void deparseAggref(Aggref *node, deparse_expr_cxt *context)
Definition: deparse.c:3446
static void appendOrderBySuffix(Oid sortop, Oid sortcoltype, bool nulls_first, deparse_expr_cxt *context)
Definition: deparse.c:3567
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:2249
#define REL_ALIAS_PREFIX
Definition: deparse.c:110
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:2135
struct deparse_expr_cxt deparse_expr_cxt
static void get_relation_column_alias_ids(Var *node, RelOptInfo *foreignrel, int *relno, int *colno)
Definition: deparse.c:3939
void deparseAnalyzeSql(StringInfo buf, Relation rel, List **retrieved_attrs)
Definition: deparse.c:2377
FDWCollateState
Definition: deparse.c:81
@ FDW_COLLATE_SAFE
Definition: deparse.c:85
@ FDW_COLLATE_UNSAFE
Definition: deparse.c:86
@ FDW_COLLATE_NONE
Definition: deparse.c:82
static void printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod, deparse_expr_cxt *context)
Definition: deparse.c:3612
static bool is_subquery_var(Var *node, RelOptInfo *foreignrel, int *relno, int *colno)
Definition: deparse.c:3877
bool is_foreign_param(PlannerInfo *root, RelOptInfo *baserel, Expr *expr)
Definition: deparse.c:1078
static void printRemotePlaceholder(Oid paramtype, int32 paramtypmod, deparse_expr_cxt *context)
Definition: deparse.c:3638
static void appendOrderByClause(List *pathkeys, bool has_final_sort, deparse_expr_cxt *context)
Definition: deparse.c:3692
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:308
static void deparseColumnRef(StringInfo buf, int varno, int varattno, RangeTblEntry *rte, bool qualify_col)
Definition: deparse.c:2470
static void deparseRelabelType(RelabelType *node, deparse_expr_cxt *context)
Definition: deparse.c:3286
static void deparseNullTest(NullTest *node, deparse_expr_cxt *context)
Definition: deparse.c:3337
static void deparseOperatorName(StringInfo buf, Form_pg_operator opform)
Definition: deparse.c:3195
static void deparseOpExpr(OpExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3065
static void deparseConst(Const *node, deparse_expr_cxt *context, int showtype)
Definition: deparse.c:2809
static bool isPlainForeignVar(Expr *node, deparse_expr_cxt *context)
Definition: deparse.c:3160
static void deparseDistinctExpr(DistinctExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3223
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:1229
static void deparseFuncExpr(FuncExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3002
void deparseStringLiteral(StringInfo buf, const char *val)
Definition: deparse.c:2638
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:2015
struct foreign_glob_cxt foreign_glob_cxt
static void deparseArrayExpr(ArrayExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3420
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:1942
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:2300
void deparseUpdateSql(StringInfo buf, RangeTblEntry *rte, Index rtindex, Relation rel, List *targetAttrs, List *withCheckOptionList, List *returningList, List **retrieved_attrs)
Definition: deparse.c:2075
static void deparseVar(Var *node, deparse_expr_cxt *context)
Definition: deparse.c:2738
static void appendFunctionName(Oid funcid, deparse_expr_cxt *context)
Definition: deparse.c:3797
static void appendConditions(List *exprs, deparse_expr_cxt *context)
Definition: deparse.c:1569
struct foreign_loc_cxt foreign_loc_cxt
void deparseDeleteSql(StringInfo buf, RangeTblEntry *rte, Index rtindex, Relation rel, List *returningList, List **retrieved_attrs)
Definition: deparse.c:2220
static void deparseSubscriptingRef(SubscriptingRef *node, deparse_expr_cxt *context)
Definition: deparse.c:2956
static void deparseRelation(StringInfo buf, Relation rel)
Definition: deparse.c:2598
static void deparseExplicitTargetList(List *tlist, bool is_returning, List **retrieved_attrs, deparse_expr_cxt *context)
Definition: deparse.c:1640
static char * deparse_type_name(Oid type_oid, int32 typemod)
Definition: deparse.c:1153
#define ADD_REL_QUALIFIER(buf, varno)
Definition: deparse.c:112
static void appendLimitClause(deparse_expr_cxt *context)
Definition: deparse.c:3769
static void deparseExpr(Expr *node, deparse_expr_cxt *context)
Definition: deparse.c:2673
bool is_foreign_expr(PlannerInfo *root, RelOptInfo *baserel, Expr *expr)
Definition: deparse.c:240
List * build_tlist_to_deparse(RelOptInfo *foreignrel)
Definition: deparse.c:1172
#define SUBQUERY_COL_ALIAS_PREFIX
Definition: deparse.c:115
void classifyConditions(PlannerInfo *root, RelOptInfo *baserel, List *input_conds, List **remote_conds, List **local_conds)
Definition: deparse.c:214
static void deparseScalarArrayOpExpr(ScalarArrayOpExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3241
static void deparseFromExprForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel, bool use_alias, Index ignore_rel, List **ignore_conds, List **params_list)
Definition: deparse.c:1717
void deparseTruncateSql(StringInfo buf, List *rels, DropBehavior behavior, bool restart_seqs)
Definition: deparse.c:2435
static void deparseSubqueryTargetList(deparse_expr_cxt *context)
Definition: deparse.c:1676
bool is_foreign_pathkey(PlannerInfo *root, RelOptInfo *baserel, PathKey *pathkey)
Definition: deparse.c:1119
static void deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_attrs, deparse_expr_cxt *context)
Definition: deparse.c:1311
static void deparseParam(Param *node, deparse_expr_cxt *context)
Definition: deparse.c:2923
static void appendAggOrderBy(List *orderList, List *targetList, deparse_expr_cxt *context)
Definition: deparse.c:3538
#define ERROR
Definition: elog.h:35
bool equal(const void *a, const void *b)
Definition: equalfuncs.c:225
char * OidOutputFunctionCall(Oid functionId, Datum val)
Definition: fmgr.c:1639
ForeignTable * GetForeignTable(Oid relid)
Definition: foreign.c:250
List * GetForeignColumnOptions(Oid relid, AttrNumber attnum)
Definition: foreign.c:288
char * format_type_extended(Oid type_oid, int32 typemod, bits16 flags)
Definition: format_type.c:112
#define HeapTupleIsValid(tuple)
Definition: htup.h:78
#define GETSTRUCT(TUP)
Definition: htup_details.h:649
long val
Definition: informix.c:664
int b
Definition: isn.c:70
int a
Definition: isn.c:69
int i
Definition: isn.c:73
if(TABLE==NULL||TABLE_index==NULL)
Definition: isn.c:77
Assert(fmt[strlen(fmt) - 1] !='\n')
List * lappend(List *list, void *datum)
Definition: list.c:338
List * lappend_int(List *list, int datum)
Definition: list.c:356
List * list_concat(List *list1, const List *list2)
Definition: list.c:560
#define NoLock
Definition: lockdefs.h:34
@ LCS_FORUPDATE
Definition: lockoptions.h:27
@ LCS_NONE
Definition: lockoptions.h:23
@ LCS_FORSHARE
Definition: lockoptions.h:25
@ LCS_FORKEYSHARE
Definition: lockoptions.h:24
@ LCS_FORNOKEYUPDATE
Definition: lockoptions.h:26
bool type_is_rowtype(Oid typid)
Definition: lsyscache.c:2613
char * get_namespace_name(Oid nspid)
Definition: lsyscache.c:3331
void getTypeOutputInfo(Oid type, Oid *typOutput, bool *typIsVarlena)
Definition: lsyscache.c:2865
Oid get_opfamily_member(Oid opfamily, Oid lefttype, Oid righttype, int16 strategy)
Definition: lsyscache.c:165
char * get_attname(Oid relid, AttrNumber attnum, bool missing_ok)
Definition: lsyscache.c:826
void pfree(void *pointer)
Definition: mcxt.c:1306
Oid exprType(const Node *expr)
Definition: nodeFuncs.c:43
bool exprIsLengthCoercion(const Node *expr, int32 *coercedTypmod)
Definition: nodeFuncs.c:500
Node * strip_implicit_coercions(Node *node)
Definition: nodeFuncs.c:648
#define IsA(nodeptr, _type_)
Definition: nodes.h:168
#define nodeTag(nodeptr)
Definition: nodes.h:122
@ CMD_DELETE
Definition: nodes.h:268
@ CMD_UPDATE
Definition: nodes.h:266
@ AGGSPLIT_SIMPLE
Definition: nodes.h:374
#define castNode(_type_, nodeptr)
Definition: nodes.h:186
JoinType
Definition: nodes.h:288
@ JOIN_FULL
Definition: nodes.h:295
@ JOIN_INNER
Definition: nodes.h:293
@ JOIN_RIGHT
Definition: nodes.h:296
@ JOIN_LEFT
Definition: nodes.h:294
#define PVC_RECURSE_PLACEHOLDERS
Definition: optimizer.h:188
Oid oprid(Operator op)
Definition: parse_oper.c:250
DropBehavior
Definition: parsenodes.h:1934
@ DROP_CASCADE
Definition: parsenodes.h:1936
@ DROP_RESTRICT
Definition: parsenodes.h:1935
#define IS_SIMPLE_REL(rel)
Definition: pathnodes.h:789
#define IS_JOIN_REL(rel)
Definition: pathnodes.h:794
#define planner_rt_fetch(rti, root)
Definition: pathnodes.h:520
@ RELOPT_JOINREL
Definition: pathnodes.h:777
#define IS_UPPER_REL(rel)
Definition: pathnodes.h:799
NameData attname
Definition: pg_attribute.h:41
int16 attnum
Definition: pg_attribute.h:83
FormData_pg_attribute * Form_pg_attribute
Definition: pg_attribute.h:207
void * arg
NameData relname
Definition: pg_class.h:38
while(p+4<=pend)
#define lfirst(lc)
Definition: pg_list.h:170
#define llast(l)
Definition: pg_list.h:196
#define lfirst_node(type, lc)
Definition: pg_list.h:174
static int list_length(const List *l)
Definition: pg_list.h:150
#define NIL
Definition: pg_list.h:66
#define forboth(cell1, list1, cell2, list2)
Definition: pg_list.h:465
#define lfirst_int(lc)
Definition: pg_list.h:171
static ListCell * list_head(const List *l)
Definition: pg_list.h:126
#define linitial(l)
Definition: pg_list.h:176
#define lsecond(l)
Definition: pg_list.h:181
static ListCell * lnext(const List *l, const ListCell *c)
Definition: pg_list.h:341
FormData_pg_operator * Form_pg_operator
Definition: pg_operator.h:83
FormData_pg_proc * Form_pg_proc
Definition: pg_proc.h:136
NameData proname
Definition: pg_proc.h:35
static char ** options
static char * buf
Definition: pg_test_fsync.c:67
static Oid DatumGetObjectId(Datum X)
Definition: postgres.h:590
static Datum ObjectIdGetDatum(Oid X)
Definition: postgres.h:600
#define InvalidOid
Definition: postgres_ext.h:36
unsigned int Oid
Definition: postgres_ext.h:31
void reset_transmission_modes(int nestlevel)
int set_transmission_modes(void)
EquivalenceMember * find_em_for_rel(PlannerInfo *root, EquivalenceClass *ec, RelOptInfo *rel)
EquivalenceMember * find_em_for_rel_target(PlannerInfo *root, EquivalenceClass *ec, RelOptInfo *rel)
bool is_shippable(Oid objectId, Oid classId, PgFdwRelationInfo *fpinfo)
Definition: shippable.c:162
bool is_builtin(Oid objectId)
Definition: shippable.c:152
char * c
static int fe(enum e x)
Definition: preproc-init.c:111
PlanRowMark * get_plan_rowmark(List *rowmarks, Index rtindex)
Definition: preptlist.c:487
@ AND_EXPR
Definition: primnodes.h:758
@ OR_EXPR
Definition: primnodes.h:758
@ NOT_EXPR
Definition: primnodes.h:758
@ PARAM_MULTIEXPR
Definition: primnodes.h:305
#define IS_SPECIAL_VARNO(varno)
Definition: primnodes.h:198
@ COERCE_IMPLICIT_CAST
Definition: primnodes.h:588
@ COERCE_EXPLICIT_CAST
Definition: primnodes.h:587
@ IS_NULL
Definition: primnodes.h:1359
#define RelationGetRelid(relation)
Definition: rel.h:501
#define RelationGetDescr(relation)
Definition: rel.h:527
#define RelationGetRelationName(relation)
Definition: rel.h:535
#define RelationGetNamespace(relation)
Definition: rel.h:542
const char * quote_identifier(const char *ident)
Definition: ruleutils.c:11529
void appendStringInfo(StringInfo str, const char *fmt,...)
Definition: stringinfo.c:91
void appendBinaryStringInfo(StringInfo str, const char *data, int datalen)
Definition: stringinfo.c:227
void appendStringInfoString(StringInfo str, const char *s)
Definition: stringinfo.c:176
void appendStringInfoChar(StringInfo str, char ch)
Definition: stringinfo.c:188
void initStringInfo(StringInfo str)
Definition: stringinfo.c:59
bool aggstar
Definition: primnodes.h:409
Oid aggfnoid
Definition: primnodes.h:373
List * aggdistinct
Definition: primnodes.h:403
List * aggdirectargs
Definition: primnodes.h:394
bool aggvariadic
Definition: primnodes.h:415
char aggkind
Definition: primnodes.h:418
List * args
Definition: primnodes.h:397
Expr * aggfilter
Definition: primnodes.h:406
Oid inputcollid
Definition: primnodes.h:382
List * aggorder
Definition: primnodes.h:400
AggSplit aggsplit
Definition: primnodes.h:427
Oid aggcollid
Definition: primnodes.h:379
Oid array_typeid
Definition: primnodes.h:1175
List * elements
Definition: primnodes.h:1178
BoolExprType boolop
Definition: primnodes.h:766
List * args
Definition: primnodes.h:767
Expr * arg
Definition: primnodes.h:1119
Oid casecollid
Definition: primnodes.h:1118
Expr * defresult
Definition: primnodes.h:1121
List * args
Definition: primnodes.h:1120
Expr * result
Definition: primnodes.h:1132
Expr * expr
Definition: primnodes.h:1131
Oid consttype
Definition: primnodes.h:259
Datum constvalue
Definition: primnodes.h:263
bool constisnull
Definition: primnodes.h:264
int32 consttypmod
Definition: primnodes.h:260
char * defname
Definition: parsenodes.h:777
List * options
Definition: foreign.h:57
Oid funcid
Definition: primnodes.h:598
bool funcvariadic
Definition: primnodes.h:601
List * args
Definition: primnodes.h:606
CoercionForm funcformat
Definition: primnodes.h:603
Oid funcresulttype
Definition: primnodes.h:599
Definition: pg_list.h:52
Definition: nodes.h:118
NullTestType nulltesttype
Definition: primnodes.h:1366
bool argisrow
Definition: primnodes.h:1367
Expr * arg
Definition: primnodes.h:1365
Oid opno
Definition: primnodes.h:648
Oid opcollid
Definition: primnodes.h:660
List * args
Definition: primnodes.h:666
Oid inputcollid
Definition: primnodes.h:663
int32 paramtypmod
Definition: primnodes.h:314
Oid paramtype
Definition: primnodes.h:313
ParamKind paramkind
Definition: primnodes.h:311
Oid paramcollid
Definition: primnodes.h:315
bool pk_nulls_first
Definition: pathnodes.h:1379
int pk_strategy
Definition: pathnodes.h:1378
Oid pk_opfamily
Definition: pathnodes.h:1377
List * exprs
Definition: pathnodes.h:1424
Relids lower_subquery_rels
Definition: postgres_fdw.h:119
RelOptInfo * outerrel
Definition: postgres_fdw.h:102
Bitmapset * attrs_used
Definition: postgres_fdw.h:50
RelOptInfo * innerrel
Definition: postgres_fdw.h:103
LockClauseStrength strength
Definition: plannodes.h:1383
Query * parse
Definition: pathnodes.h:199
List * rowMarks
Definition: pathnodes.h:358
Relids all_result_relids
Definition: pathnodes.h:341
Node * limitCount
Definition: parsenodes.h:184
List * groupClause
Definition: parsenodes.h:170
Node * limitOffset
Definition: parsenodes.h:183
CmdType commandType
Definition: parsenodes.h:124
List * groupingSets
Definition: parsenodes.h:173
Relids relids
Definition: pathnodes.h:821
struct PathTarget * reltarget
Definition: pathnodes.h:843
Index relid
Definition: pathnodes.h:868
RelOptKind reloptkind
Definition: pathnodes.h:815
Oid resultcollid
Definition: primnodes.h:1004
int32 resulttypmod
Definition: primnodes.h:1003
CoercionForm relabelformat
Definition: primnodes.h:1005
Oid resulttype
Definition: primnodes.h:1002
Expr * arg
Definition: primnodes.h:1001
TriggerDesc * trigdesc
Definition: rel.h:116
Expr * clause
Definition: pathnodes.h:2432
Index tleSortGroupRef
Definition: parsenodes.h:1320
Expr * refassgnexpr
Definition: primnodes.h:554
List * refupperindexpr
Definition: primnodes.h:547
Expr * refexpr
Definition: primnodes.h:552
List * reflowerindexpr
Definition: primnodes.h:549
Expr * expr
Definition: primnodes.h:1555
AttrNumber resno
Definition: primnodes.h:1556
bool resjunk
Definition: primnodes.h:1562
bool trig_update_after_row
Definition: reltrigger.h:62
bool trig_insert_after_row
Definition: reltrigger.h:57
bool trig_delete_after_row
Definition: reltrigger.h:67
Definition: primnodes.h:205
Oid vartype
Definition: primnodes.h:220
AttrNumber varattno
Definition: primnodes.h:217
Oid varcollid
Definition: primnodes.h:224
int varno
Definition: primnodes.h:212
int32 vartypmod
Definition: primnodes.h:222
Index varlevelsup
Definition: primnodes.h:230
PlannerInfo * root
Definition: deparse.c:101
List ** params_list
Definition: deparse.c:107
RelOptInfo * foreignrel
Definition: deparse.c:102
StringInfo buf
Definition: deparse.c:106
RelOptInfo * scanrel
Definition: deparse.c:103
RelOptInfo * foreignrel
Definition: deparse.c:71
Relids relids
Definition: deparse.c:72
PlannerInfo * root
Definition: deparse.c:70
FDWCollateState state
Definition: deparse.c:93
char data[NAMEDATALEN]
Definition: c.h:678
Definition: regguts.h:318
#define FirstLowInvalidHeapAttributeNumber
Definition: sysattr.h:27
#define TableOidAttributeNumber
Definition: sysattr.h:26
#define SelfItemPointerAttributeNumber
Definition: sysattr.h:21
void ReleaseSysCache(HeapTuple tuple)
Definition: syscache.c:1221
HeapTuple SearchSysCache1(int cacheId, Datum key1)
Definition: syscache.c:1173
@ OPEROID
Definition: syscache.h:72
@ PROCOID
Definition: syscache.h:79
void table_close(Relation relation, LOCKMODE lockmode)
Definition: table.c:126
Relation table_open(Oid relationId, LOCKMODE lockmode)
Definition: table.c:40
TargetEntry * get_sortgroupref_tle(Index sortref, List *targetList)
Definition: tlist.c:345
List * add_to_flat_tlist(List *tlist, List *exprs)
Definition: tlist.c:132
#define FirstNormalObjectId
Definition: transam.h:197
#define TupleDescAttr(tupdesc, i)
Definition: tupdesc.h:92
TypeCacheEntry * lookup_type_cache(Oid type_id, int flags)
Definition: typcache.c:339
#define TYPECACHE_GT_OPR
Definition: typcache.h:138
#define TYPECACHE_LT_OPR
Definition: typcache.h:137
List * pull_var_clause(Node *node, int flags)
Definition: var.c:597
void pull_varattnos(Node *node, Index varno, Bitmapset **varattnos)
Definition: var.c:281