PostgreSQL Source Code  git master
file_fdw.c File Reference
#include "postgres.h"
#include <sys/stat.h>
#include <unistd.h>
#include "access/htup_details.h"
#include "access/reloptions.h"
#include "access/sysattr.h"
#include "access/table.h"
#include "catalog/pg_authid.h"
#include "catalog/pg_foreign_table.h"
#include "commands/copy.h"
#include "commands/defrem.h"
#include "commands/explain.h"
#include "commands/vacuum.h"
#include "foreign/fdwapi.h"
#include "foreign/foreign.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "optimizer/optimizer.h"
#include "optimizer/pathnode.h"
#include "optimizer/planmain.h"
#include "optimizer/restrictinfo.h"
#include "utils/acl.h"
#include "utils/memutils.h"
#include "utils/rel.h"
#include "utils/sampling.h"
#include "utils/varlena.h"
Include dependency graph for file_fdw.c:

Go to the source code of this file.

Data Structures

struct  FileFdwOption
 
struct  FileFdwPlanState
 
struct  FileFdwExecutionState
 

Typedefs

typedef struct FileFdwPlanState FileFdwPlanState
 
typedef struct FileFdwExecutionState FileFdwExecutionState
 

Functions

 PG_FUNCTION_INFO_V1 (file_fdw_handler)
 
 PG_FUNCTION_INFO_V1 (file_fdw_validator)
 
static void fileGetForeignRelSize (PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid)
 
static void fileGetForeignPaths (PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid)
 
static ForeignScanfileGetForeignPlan (PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid, ForeignPath *best_path, List *tlist, List *scan_clauses, Plan *outer_plan)
 
static void fileExplainForeignScan (ForeignScanState *node, ExplainState *es)
 
static void fileBeginForeignScan (ForeignScanState *node, int eflags)
 
static TupleTableSlotfileIterateForeignScan (ForeignScanState *node)
 
static void fileReScanForeignScan (ForeignScanState *node)
 
static void fileEndForeignScan (ForeignScanState *node)
 
static bool fileAnalyzeForeignTable (Relation relation, AcquireSampleRowsFunc *func, BlockNumber *totalpages)
 
static bool fileIsForeignScanParallelSafe (PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
 
static bool is_valid_option (const char *option, Oid context)
 
static void fileGetOptions (Oid foreigntableid, char **filename, bool *is_program, List **other_options)
 
static Listget_file_fdw_attribute_options (Oid relid)
 
static bool check_selective_binary_conversion (RelOptInfo *baserel, Oid foreigntableid, List **columns)
 
static void estimate_size (PlannerInfo *root, RelOptInfo *baserel, FileFdwPlanState *fdw_private)
 
static void estimate_costs (PlannerInfo *root, RelOptInfo *baserel, FileFdwPlanState *fdw_private, Cost *startup_cost, Cost *total_cost)
 
static int file_acquire_sample_rows (Relation onerel, int elevel, HeapTuple *rows, int targrows, double *totalrows, double *totaldeadrows)
 
Datum file_fdw_handler (PG_FUNCTION_ARGS)
 
Datum file_fdw_validator (PG_FUNCTION_ARGS)
 

Variables

 PG_MODULE_MAGIC
 
static const struct FileFdwOption valid_options []
 

Typedef Documentation

◆ FileFdwExecutionState

◆ FileFdwPlanState

Function Documentation

◆ check_selective_binary_conversion()

static bool check_selective_binary_conversion ( RelOptInfo baserel,
Oid  foreigntableid,
List **  columns 
)
static

Definition at line 874 of file file_fdw.c.

877 {
878  ForeignTable *table;
879  ListCell *lc;
880  Relation rel;
881  TupleDesc tupleDesc;
882  int attidx;
883  Bitmapset *attrs_used = NULL;
884  bool has_wholerow = false;
885  int numattrs;
886  int i;
887 
888  *columns = NIL; /* default result */
889 
890  /*
891  * Check format of the file. If binary format, this is irrelevant.
892  */
893  table = GetForeignTable(foreigntableid);
894  foreach(lc, table->options)
895  {
896  DefElem *def = (DefElem *) lfirst(lc);
897 
898  if (strcmp(def->defname, "format") == 0)
899  {
900  char *format = defGetString(def);
901 
902  if (strcmp(format, "binary") == 0)
903  return false;
904  break;
905  }
906  }
907 
908  /* Collect all the attributes needed for joins or final output. */
909  pull_varattnos((Node *) baserel->reltarget->exprs, baserel->relid,
910  &attrs_used);
911 
912  /* Add all the attributes used by restriction clauses. */
913  foreach(lc, baserel->baserestrictinfo)
914  {
915  RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
916 
917  pull_varattnos((Node *) rinfo->clause, baserel->relid,
918  &attrs_used);
919  }
920 
921  /* Convert attribute numbers to column names. */
922  rel = table_open(foreigntableid, AccessShareLock);
923  tupleDesc = RelationGetDescr(rel);
924 
925  attidx = -1;
926  while ((attidx = bms_next_member(attrs_used, attidx)) >= 0)
927  {
928  /* attidx is zero-based, attnum is the normal attribute number */
930 
931  if (attnum == 0)
932  {
933  has_wholerow = true;
934  break;
935  }
936 
937  /* Ignore system attributes. */
938  if (attnum < 0)
939  continue;
940 
941  /* Get user attributes. */
942  if (attnum > 0)
943  {
944  Form_pg_attribute attr = TupleDescAttr(tupleDesc, attnum - 1);
945  char *attname = NameStr(attr->attname);
946 
947  /* Skip dropped attributes (probably shouldn't see any here). */
948  if (attr->attisdropped)
949  continue;
950 
951  /*
952  * Skip generated columns (COPY won't accept them in the column
953  * list)
954  */
955  if (attr->attgenerated)
956  continue;
957  *columns = lappend(*columns, makeString(pstrdup(attname)));
958  }
959  }
960 
961  /* Count non-dropped user attributes while we have the tupdesc. */
962  numattrs = 0;
963  for (i = 0; i < tupleDesc->natts; i++)
964  {
965  Form_pg_attribute attr = TupleDescAttr(tupleDesc, i);
966 
967  if (attr->attisdropped)
968  continue;
969  numattrs++;
970  }
971 
973 
974  /* If there's a whole-row reference, fail: we need all the columns. */
975  if (has_wholerow)
976  {
977  *columns = NIL;
978  return false;
979  }
980 
981  /* If all the user attributes are needed, fail. */
982  if (numattrs == list_length(*columns))
983  {
984  *columns = NIL;
985  return false;
986  }
987 
988  return true;
989 }
int16 AttrNumber
Definition: attnum.h:21
int bms_next_member(const Bitmapset *a, int prevbit)
Definition: bitmapset.c:1306
#define NameStr(name)
Definition: c.h:746
char * defGetString(DefElem *def)
Definition: define.c:48
ForeignTable * GetForeignTable(Oid relid)
Definition: foreign.c:253
int i
Definition: isn.c:73
List * lappend(List *list, void *datum)
Definition: list.c:339
#define AccessShareLock
Definition: lockdefs.h:36
char * pstrdup(const char *in)
Definition: mcxt.c:1695
NameData attname
Definition: pg_attribute.h:41
int16 attnum
Definition: pg_attribute.h:74
FormData_pg_attribute * Form_pg_attribute
Definition: pg_attribute.h:209
static char format
#define lfirst(lc)
Definition: pg_list.h:172
static int list_length(const List *l)
Definition: pg_list.h:152
#define NIL
Definition: pg_list.h:68
#define RelationGetDescr(relation)
Definition: rel.h:531
char * defname
Definition: parsenodes.h:815
List * options
Definition: foreign.h:57
Definition: nodes.h:129
List * exprs
Definition: pathnodes.h:1533
List * baserestrictinfo
Definition: pathnodes.h:979
struct PathTarget * reltarget
Definition: pathnodes.h:887
Index relid
Definition: pathnodes.h:912
Expr * clause
Definition: pathnodes.h:2564
#define FirstLowInvalidHeapAttributeNumber
Definition: sysattr.h:27
void table_close(Relation relation, LOCKMODE lockmode)
Definition: table.c:126
Relation table_open(Oid relationId, LOCKMODE lockmode)
Definition: table.c:40
#define TupleDescAttr(tupdesc, i)
Definition: tupdesc.h:92
String * makeString(char *str)
Definition: value.c:63
void pull_varattnos(Node *node, Index varno, Bitmapset **varattnos)
Definition: var.c:291

References AccessShareLock, attname, attnum, RelOptInfo::baserestrictinfo, bms_next_member(), RestrictInfo::clause, defGetString(), DefElem::defname, PathTarget::exprs, FirstLowInvalidHeapAttributeNumber, format, GetForeignTable(), i, lappend(), lfirst, list_length(), makeString(), NameStr, TupleDescData::natts, NIL, ForeignTable::options, pstrdup(), pull_varattnos(), RelationGetDescr, RelOptInfo::relid, RelOptInfo::reltarget, table_close(), table_open(), and TupleDescAttr.

Referenced by fileGetForeignPaths().

◆ estimate_costs()

static void estimate_costs ( PlannerInfo root,
RelOptInfo baserel,
FileFdwPlanState fdw_private,
Cost startup_cost,
Cost total_cost 
)
static

Definition at line 1080 of file file_fdw.c.

1083 {
1084  BlockNumber pages = fdw_private->pages;
1085  double ntuples = fdw_private->ntuples;
1086  Cost run_cost = 0;
1087  Cost cpu_per_tuple;
1088 
1089  /*
1090  * We estimate costs almost the same way as cost_seqscan(), thus assuming
1091  * that I/O costs are equivalent to a regular table file of the same size.
1092  * However, we take per-tuple CPU costs as 10x of a seqscan, to account
1093  * for the cost of parsing records.
1094  *
1095  * In the case of a program source, this calculation is even more divorced
1096  * from reality, but we have no good alternative; and it's not clear that
1097  * the numbers we produce here matter much anyway, since there's only one
1098  * access path for the rel.
1099  */
1100  run_cost += seq_page_cost * pages;
1101 
1102  *startup_cost = baserel->baserestrictcost.startup;
1103  cpu_per_tuple = cpu_tuple_cost * 10 + baserel->baserestrictcost.per_tuple;
1104  run_cost += cpu_per_tuple * ntuples;
1105  *total_cost = *startup_cost + run_cost;
1106 }
uint32 BlockNumber
Definition: block.h:31
double cpu_tuple_cost
Definition: costsize.c:121
double seq_page_cost
Definition: costsize.c:119
double Cost
Definition: nodes.h:251
double ntuples
Definition: file_fdw.c:98
BlockNumber pages
Definition: file_fdw.c:97
Cost per_tuple
Definition: pathnodes.h:48
Cost startup
Definition: pathnodes.h:47
QualCost baserestrictcost
Definition: pathnodes.h:981

References RelOptInfo::baserestrictcost, cpu_tuple_cost, FileFdwPlanState::ntuples, FileFdwPlanState::pages, QualCost::per_tuple, seq_page_cost, and QualCost::startup.

Referenced by fileGetForeignPaths().

◆ estimate_size()

static void estimate_size ( PlannerInfo root,
RelOptInfo baserel,
FileFdwPlanState fdw_private 
)
static

Definition at line 999 of file file_fdw.c.

1001 {
1002  struct stat stat_buf;
1003  BlockNumber pages;
1004  double ntuples;
1005  double nrows;
1006 
1007  /*
1008  * Get size of the file. It might not be there at plan time, though, in
1009  * which case we have to use a default estimate. We also have to fall
1010  * back to the default if using a program as the input.
1011  */
1012  if (fdw_private->is_program || stat(fdw_private->filename, &stat_buf) < 0)
1013  stat_buf.st_size = 10 * BLCKSZ;
1014 
1015  /*
1016  * Convert size to pages for use in I/O cost estimate later.
1017  */
1018  pages = (stat_buf.st_size + (BLCKSZ - 1)) / BLCKSZ;
1019  if (pages < 1)
1020  pages = 1;
1021  fdw_private->pages = pages;
1022 
1023  /*
1024  * Estimate the number of tuples in the file.
1025  */
1026  if (baserel->tuples >= 0 && baserel->pages > 0)
1027  {
1028  /*
1029  * We have # of pages and # of tuples from pg_class (that is, from a
1030  * previous ANALYZE), so compute a tuples-per-page estimate and scale
1031  * that by the current file size.
1032  */
1033  double density;
1034 
1035  density = baserel->tuples / (double) baserel->pages;
1036  ntuples = clamp_row_est(density * (double) pages);
1037  }
1038  else
1039  {
1040  /*
1041  * Otherwise we have to fake it. We back into this estimate using the
1042  * planner's idea of the relation width; which is bogus if not all
1043  * columns are being read, not to mention that the text representation
1044  * of a row probably isn't the same size as its internal
1045  * representation. Possibly we could do something better, but the
1046  * real answer to anyone who complains is "ANALYZE" ...
1047  */
1048  int tuple_width;
1049 
1050  tuple_width = MAXALIGN(baserel->reltarget->width) +
1052  ntuples = clamp_row_est((double) stat_buf.st_size /
1053  (double) tuple_width);
1054  }
1055  fdw_private->ntuples = ntuples;
1056 
1057  /*
1058  * Now estimate the number of rows returned by the scan after applying the
1059  * baserestrictinfo quals.
1060  */
1061  nrows = ntuples *
1063  baserel->baserestrictinfo,
1064  0,
1065  JOIN_INNER,
1066  NULL);
1067 
1068  nrows = clamp_row_est(nrows);
1069 
1070  /* Save the output-rows estimate for the planner */
1071  baserel->rows = nrows;
1072 }
#define MAXALIGN(LEN)
Definition: c.h:811
Selectivity clauselist_selectivity(PlannerInfo *root, List *clauses, int varRelid, JoinType jointype, SpecialJoinInfo *sjinfo)
Definition: clausesel.c:100
double clamp_row_est(double nrows)
Definition: costsize.c:202
#define SizeofHeapTupleHeader
Definition: htup_details.h:185
@ JOIN_INNER
Definition: nodes.h:293
tree ctl root
Definition: radixtree.h:1884
char * filename
Definition: file_fdw.c:93
Cardinality tuples
Definition: pathnodes.h:943
BlockNumber pages
Definition: pathnodes.h:942
Cardinality rows
Definition: pathnodes.h:871
__int64 st_size
Definition: win32_port.h:273

References RelOptInfo::baserestrictinfo, clamp_row_est(), clauselist_selectivity(), FileFdwPlanState::filename, FileFdwPlanState::is_program, JOIN_INNER, MAXALIGN, FileFdwPlanState::ntuples, FileFdwPlanState::pages, RelOptInfo::pages, RelOptInfo::reltarget, root, RelOptInfo::rows, SizeofHeapTupleHeader, stat::st_size, RelOptInfo::tuples, and PathTarget::width.

Referenced by fileGetForeignRelSize().

◆ file_acquire_sample_rows()

static int file_acquire_sample_rows ( Relation  onerel,
int  elevel,
HeapTuple rows,
int  targrows,
double *  totalrows,
double *  totaldeadrows 
)
static

Definition at line 1123 of file file_fdw.c.

1126 {
1127  int numrows = 0;
1128  double rowstoskip = -1; /* -1 means not set yet */
1129  ReservoirStateData rstate;
1130  TupleDesc tupDesc;
1131  Datum *values;
1132  bool *nulls;
1133  bool found;
1134  char *filename;
1135  bool is_program;
1136  List *options;
1137  CopyFromState cstate;
1138  ErrorContextCallback errcallback;
1139  MemoryContext oldcontext = CurrentMemoryContext;
1140  MemoryContext tupcontext;
1141 
1142  Assert(onerel);
1143  Assert(targrows > 0);
1144 
1145  tupDesc = RelationGetDescr(onerel);
1146  values = (Datum *) palloc(tupDesc->natts * sizeof(Datum));
1147  nulls = (bool *) palloc(tupDesc->natts * sizeof(bool));
1148 
1149  /* Fetch options of foreign table */
1150  fileGetOptions(RelationGetRelid(onerel), &filename, &is_program, &options);
1151 
1152  /*
1153  * Create CopyState from FDW options.
1154  */
1155  cstate = BeginCopyFrom(NULL, onerel, NULL, filename, is_program, NULL, NIL,
1156  options);
1157 
1158  /*
1159  * Use per-tuple memory context to prevent leak of memory used to read
1160  * rows from the file with Copy routines.
1161  */
1163  "file_fdw temporary context",
1165 
1166  /* Prepare for sampling rows */
1167  reservoir_init_selection_state(&rstate, targrows);
1168 
1169  /* Set up callback to identify error line number. */
1170  errcallback.callback = CopyFromErrorCallback;
1171  errcallback.arg = (void *) cstate;
1172  errcallback.previous = error_context_stack;
1173  error_context_stack = &errcallback;
1174 
1175  *totalrows = 0;
1176  *totaldeadrows = 0;
1177  for (;;)
1178  {
1179  /* Check for user-requested abort or sleep */
1181 
1182  /* Fetch next row */
1183  MemoryContextReset(tupcontext);
1184  MemoryContextSwitchTo(tupcontext);
1185 
1186  found = NextCopyFrom(cstate, NULL, values, nulls);
1187 
1188  MemoryContextSwitchTo(oldcontext);
1189 
1190  if (!found)
1191  break;
1192 
1193  /*
1194  * The first targrows sample rows are simply copied into the
1195  * reservoir. Then we start replacing tuples in the sample until we
1196  * reach the end of the relation. This algorithm is from Jeff Vitter's
1197  * paper (see more info in commands/analyze.c).
1198  */
1199  if (numrows < targrows)
1200  {
1201  rows[numrows++] = heap_form_tuple(tupDesc, values, nulls);
1202  }
1203  else
1204  {
1205  /*
1206  * t in Vitter's paper is the number of records already processed.
1207  * If we need to compute a new S value, we must use the
1208  * not-yet-incremented value of totalrows as t.
1209  */
1210  if (rowstoskip < 0)
1211  rowstoskip = reservoir_get_next_S(&rstate, *totalrows, targrows);
1212 
1213  if (rowstoskip <= 0)
1214  {
1215  /*
1216  * Found a suitable tuple, so save it, replacing one old tuple
1217  * at random
1218  */
1219  int k = (int) (targrows * sampler_random_fract(&rstate.randstate));
1220 
1221  Assert(k >= 0 && k < targrows);
1222  heap_freetuple(rows[k]);
1223  rows[k] = heap_form_tuple(tupDesc, values, nulls);
1224  }
1225 
1226  rowstoskip -= 1;
1227  }
1228 
1229  *totalrows += 1;
1230  }
1231 
1232  /* Remove error callback. */
1233  error_context_stack = errcallback.previous;
1234 
1235  /* Clean up. */
1236  MemoryContextDelete(tupcontext);
1237 
1238  EndCopyFrom(cstate);
1239 
1240  pfree(values);
1241  pfree(nulls);
1242 
1243  /*
1244  * Emit some interesting relation info
1245  */
1246  ereport(elevel,
1247  (errmsg("\"%s\": file contains %.0f rows; "
1248  "%d rows in sample",
1249  RelationGetRelationName(onerel),
1250  *totalrows, numrows)));
1251 
1252  return numrows;
1253 }
static Datum values[MAXATTR]
Definition: bootstrap.c:152
#define Assert(condition)
Definition: c.h:858
CopyFromState BeginCopyFrom(ParseState *pstate, Relation rel, Node *whereClause, const char *filename, bool is_program, copy_data_source_cb data_source_cb, List *attnamelist, List *options)
Definition: copyfrom.c:1368
void EndCopyFrom(CopyFromState cstate)
Definition: copyfrom.c:1785
void CopyFromErrorCallback(void *arg)
Definition: copyfrom.c:112
bool NextCopyFrom(CopyFromState cstate, ExprContext *econtext, Datum *values, bool *nulls)
ErrorContextCallback * error_context_stack
Definition: elog.c:94
int errmsg(const char *fmt,...)
Definition: elog.c:1070
#define ereport(elevel,...)
Definition: elog.h:149
static void fileGetOptions(Oid foreigntableid, char **filename, bool *is_program, List **other_options)
Definition: file_fdw.c:370
HeapTuple heap_form_tuple(TupleDesc tupleDescriptor, const Datum *values, const bool *isnull)
Definition: heaptuple.c:1116
void heap_freetuple(HeapTuple htup)
Definition: heaptuple.c:1434
void MemoryContextReset(MemoryContext context)
Definition: mcxt.c:383
void pfree(void *pointer)
Definition: mcxt.c:1520
MemoryContext CurrentMemoryContext
Definition: mcxt.c:143
void MemoryContextDelete(MemoryContext context)
Definition: mcxt.c:454
void * palloc(Size size)
Definition: mcxt.c:1316
#define AllocSetContextCreate
Definition: memutils.h:129
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:160
static char * filename
Definition: pg_dumpall.c:119
static char ** options
uintptr_t Datum
Definition: postgres.h:64
MemoryContextSwitchTo(old_ctx)
#define RelationGetRelid(relation)
Definition: rel.h:505
#define RelationGetRelationName(relation)
Definition: rel.h:539
void reservoir_init_selection_state(ReservoirState rs, int n)
Definition: sampling.c:133
double sampler_random_fract(pg_prng_state *randstate)
Definition: sampling.c:241
double reservoir_get_next_S(ReservoirState rs, double t, int n)
Definition: sampling.c:147
struct ErrorContextCallback * previous
Definition: elog.h:295
void(* callback)(void *arg)
Definition: elog.h:296
Definition: pg_list.h:54
pg_prng_state randstate
Definition: sampling.h:49
void vacuum_delay_point(void)
Definition: vacuum.c:2340

References ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate, ErrorContextCallback::arg, Assert, BeginCopyFrom(), ErrorContextCallback::callback, CopyFromErrorCallback(), CurrentMemoryContext, EndCopyFrom(), ereport, errmsg(), error_context_stack, fileGetOptions(), filename, heap_form_tuple(), heap_freetuple(), MemoryContextDelete(), MemoryContextReset(), MemoryContextSwitchTo(), TupleDescData::natts, NextCopyFrom(), NIL, options, palloc(), pfree(), ErrorContextCallback::previous, ReservoirStateData::randstate, RelationGetDescr, RelationGetRelationName, RelationGetRelid, reservoir_get_next_S(), reservoir_init_selection_state(), sampler_random_fract(), vacuum_delay_point(), and values.

Referenced by fileAnalyzeForeignTable().

◆ file_fdw_handler()

Datum file_fdw_handler ( PG_FUNCTION_ARGS  )

Definition at line 173 of file file_fdw.c.

174 {
175  FdwRoutine *fdwroutine = makeNode(FdwRoutine);
176 
178  fdwroutine->GetForeignPaths = fileGetForeignPaths;
179  fdwroutine->GetForeignPlan = fileGetForeignPlan;
184  fdwroutine->EndForeignScan = fileEndForeignScan;
187 
188  PG_RETURN_POINTER(fdwroutine);
189 }
static ForeignScan * fileGetForeignPlan(PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid, ForeignPath *best_path, List *tlist, List *scan_clauses, Plan *outer_plan)
Definition: file_fdw.c:599
static void fileEndForeignScan(ForeignScanState *node)
Definition: file_fdw.c:793
static void fileGetForeignRelSize(PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid)
Definition: file_fdw.c:514
static void fileExplainForeignScan(ForeignScanState *node, ExplainState *es)
Definition: file_fdw.c:634
static bool fileAnalyzeForeignTable(Relation relation, AcquireSampleRowsFunc *func, BlockNumber *totalpages)
Definition: file_fdw.c:807
static void fileReScanForeignScan(ForeignScanState *node)
Definition: file_fdw.c:772
static bool fileIsForeignScanParallelSafe(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: file_fdw.c:858
static void fileGetForeignPaths(PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid)
Definition: file_fdw.c:545
static void fileBeginForeignScan(ForeignScanState *node, int eflags)
Definition: file_fdw.c:666
static TupleTableSlot * fileIterateForeignScan(ForeignScanState *node)
Definition: file_fdw.c:720
#define PG_RETURN_POINTER(x)
Definition: fmgr.h:361
#define makeNode(_type_)
Definition: nodes.h:155
ReScanForeignScan_function ReScanForeignScan
Definition: fdwapi.h:214
BeginForeignScan_function BeginForeignScan
Definition: fdwapi.h:212
IsForeignScanParallelSafe_function IsForeignScanParallelSafe
Definition: fdwapi.h:266
GetForeignPaths_function GetForeignPaths
Definition: fdwapi.h:210
GetForeignRelSize_function GetForeignRelSize
Definition: fdwapi.h:209
ExplainForeignScan_function ExplainForeignScan
Definition: fdwapi.h:252
EndForeignScan_function EndForeignScan
Definition: fdwapi.h:215
AnalyzeForeignTable_function AnalyzeForeignTable
Definition: fdwapi.h:257
IterateForeignScan_function IterateForeignScan
Definition: fdwapi.h:213
GetForeignPlan_function GetForeignPlan
Definition: fdwapi.h:211

References FdwRoutine::AnalyzeForeignTable, FdwRoutine::BeginForeignScan, FdwRoutine::EndForeignScan, FdwRoutine::ExplainForeignScan, fileAnalyzeForeignTable(), fileBeginForeignScan(), fileEndForeignScan(), fileExplainForeignScan(), fileGetForeignPaths(), fileGetForeignPlan(), fileGetForeignRelSize(), fileIsForeignScanParallelSafe(), fileIterateForeignScan(), fileReScanForeignScan(), FdwRoutine::GetForeignPaths, FdwRoutine::GetForeignPlan, FdwRoutine::GetForeignRelSize, FdwRoutine::IsForeignScanParallelSafe, FdwRoutine::IterateForeignScan, makeNode, PG_RETURN_POINTER, and FdwRoutine::ReScanForeignScan.

◆ file_fdw_validator()

Datum file_fdw_validator ( PG_FUNCTION_ARGS  )

Definition at line 198 of file file_fdw.c.

199 {
200  List *options_list = untransformRelOptions(PG_GETARG_DATUM(0));
201  Oid catalog = PG_GETARG_OID(1);
202  char *filename = NULL;
203  DefElem *force_not_null = NULL;
204  DefElem *force_null = NULL;
205  List *other_options = NIL;
206  ListCell *cell;
207 
208  /*
209  * Check that only options supported by file_fdw, and allowed for the
210  * current object type, are given.
211  */
212  foreach(cell, options_list)
213  {
214  DefElem *def = (DefElem *) lfirst(cell);
215 
216  if (!is_valid_option(def->defname, catalog))
217  {
218  const struct FileFdwOption *opt;
219  const char *closest_match;
221  bool has_valid_options = false;
222 
223  /*
224  * Unknown option specified, complain about it. Provide a hint
225  * with a valid option that looks similar, if there is one.
226  */
228  for (opt = valid_options; opt->optname; opt++)
229  {
230  if (catalog == opt->optcontext)
231  {
232  has_valid_options = true;
234  }
235  }
236 
237  closest_match = getClosestMatch(&match_state);
238  ereport(ERROR,
239  (errcode(ERRCODE_FDW_INVALID_OPTION_NAME),
240  errmsg("invalid option \"%s\"", def->defname),
241  has_valid_options ? closest_match ?
242  errhint("Perhaps you meant the option \"%s\".",
243  closest_match) : 0 :
244  errhint("There are no valid options in this context.")));
245  }
246 
247  /*
248  * Separate out filename, program, and column-specific options, since
249  * ProcessCopyOptions won't accept them.
250  */
251  if (strcmp(def->defname, "filename") == 0 ||
252  strcmp(def->defname, "program") == 0)
253  {
254  if (filename)
255  ereport(ERROR,
256  (errcode(ERRCODE_SYNTAX_ERROR),
257  errmsg("conflicting or redundant options")));
258 
259  /*
260  * Check permissions for changing which file or program is used by
261  * the file_fdw.
262  *
263  * Only members of the role 'pg_read_server_files' are allowed to
264  * set the 'filename' option of a file_fdw foreign table, while
265  * only members of the role 'pg_execute_server_program' are
266  * allowed to set the 'program' option. This is because we don't
267  * want regular users to be able to control which file gets read
268  * or which program gets executed.
269  *
270  * Putting this sort of permissions check in a validator is a bit
271  * of a crock, but there doesn't seem to be any other place that
272  * can enforce the check more cleanly.
273  *
274  * Note that the valid_options[] array disallows setting filename
275  * and program at any options level other than foreign table ---
276  * otherwise there'd still be a security hole.
277  */
278  if (strcmp(def->defname, "filename") == 0 &&
279  !has_privs_of_role(GetUserId(), ROLE_PG_READ_SERVER_FILES))
280  ereport(ERROR,
281  (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
282  errmsg("permission denied to set the \"%s\" option of a file_fdw foreign table",
283  "filename"),
284  errdetail("Only roles with privileges of the \"%s\" role may set this option.",
285  "pg_read_server_files")));
286 
287  if (strcmp(def->defname, "program") == 0 &&
288  !has_privs_of_role(GetUserId(), ROLE_PG_EXECUTE_SERVER_PROGRAM))
289  ereport(ERROR,
290  (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
291  errmsg("permission denied to set the \"%s\" option of a file_fdw foreign table",
292  "program"),
293  errdetail("Only roles with privileges of the \"%s\" role may set this option.",
294  "pg_execute_server_program")));
295 
296  filename = defGetString(def);
297  }
298 
299  /*
300  * force_not_null is a boolean option; after validation we can discard
301  * it - it will be retrieved later in get_file_fdw_attribute_options()
302  */
303  else if (strcmp(def->defname, "force_not_null") == 0)
304  {
305  if (force_not_null)
306  ereport(ERROR,
307  (errcode(ERRCODE_SYNTAX_ERROR),
308  errmsg("conflicting or redundant options"),
309  errhint("Option \"force_not_null\" supplied more than once for a column.")));
310  force_not_null = def;
311  /* Don't care what the value is, as long as it's a legal boolean */
312  (void) defGetBoolean(def);
313  }
314  /* See comments for force_not_null above */
315  else if (strcmp(def->defname, "force_null") == 0)
316  {
317  if (force_null)
318  ereport(ERROR,
319  (errcode(ERRCODE_SYNTAX_ERROR),
320  errmsg("conflicting or redundant options"),
321  errhint("Option \"force_null\" supplied more than once for a column.")));
322  force_null = def;
323  (void) defGetBoolean(def);
324  }
325  else
326  other_options = lappend(other_options, def);
327  }
328 
329  /*
330  * Now apply the core COPY code's validation logic for more checks.
331  */
332  ProcessCopyOptions(NULL, NULL, true, other_options);
333 
334  /*
335  * Either filename or program option is required for file_fdw foreign
336  * tables.
337  */
338  if (catalog == ForeignTableRelationId && filename == NULL)
339  ereport(ERROR,
340  (errcode(ERRCODE_FDW_DYNAMIC_PARAMETER_VALUE_NEEDED),
341  errmsg("either filename or program is required for file_fdw foreign tables")));
342 
343  PG_RETURN_VOID();
344 }
bool has_privs_of_role(Oid member, Oid role)
Definition: acl.c:5128
void ProcessCopyOptions(ParseState *pstate, CopyFormatOptions *opts_out, bool is_from, List *options)
Definition: copy.c:459
bool defGetBoolean(DefElem *def)
Definition: define.c:107
int errdetail(const char *fmt,...)
Definition: elog.c:1203
int errhint(const char *fmt,...)
Definition: elog.c:1317
int errcode(int sqlerrcode)
Definition: elog.c:857
#define ERROR
Definition: elog.h:39
static const struct FileFdwOption valid_options[]
Definition: file_fdw.c:62
static bool is_valid_option(const char *option, Oid context)
Definition: file_fdw.c:351
#define PG_RETURN_VOID()
Definition: fmgr.h:349
#define PG_GETARG_OID(n)
Definition: fmgr.h:275
#define PG_GETARG_DATUM(n)
Definition: fmgr.h:268
struct parser_state match_state[5]
Oid GetUserId(void)
Definition: miscinit.c:514
unsigned int Oid
Definition: postgres_ext.h:31
List * untransformRelOptions(Datum options)
Definition: reloptions.c:1331
Oid optcontext
Definition: file_fdw.c:50
const char * optname
Definition: file_fdw.c:49
const char * getClosestMatch(ClosestMatchState *state)
Definition: varlena.c:6243
void initClosestMatch(ClosestMatchState *state, const char *source, int max_d)
Definition: varlena.c:6188
void updateClosestMatch(ClosestMatchState *state, const char *candidate)
Definition: varlena.c:6208

References defGetBoolean(), defGetString(), DefElem::defname, ereport, errcode(), errdetail(), errhint(), errmsg(), ERROR, filename, getClosestMatch(), GetUserId(), has_privs_of_role(), initClosestMatch(), is_valid_option(), lappend(), lfirst, match_state, NIL, FileFdwOption::optcontext, FileFdwOption::optname, PG_GETARG_DATUM, PG_GETARG_OID, PG_RETURN_VOID, ProcessCopyOptions(), untransformRelOptions(), updateClosestMatch(), and valid_options.

◆ fileAnalyzeForeignTable()

static bool fileAnalyzeForeignTable ( Relation  relation,
AcquireSampleRowsFunc func,
BlockNumber totalpages 
)
static

Definition at line 807 of file file_fdw.c.

810 {
811  char *filename;
812  bool is_program;
813  List *options;
814  struct stat stat_buf;
815 
816  /* Fetch options of foreign table */
817  fileGetOptions(RelationGetRelid(relation), &filename, &is_program, &options);
818 
819  /*
820  * If this is a program instead of a file, just return false to skip
821  * analyzing the table. We could run the program and collect stats on
822  * whatever it currently returns, but it seems likely that in such cases
823  * the output would be too volatile for the stats to be useful. Maybe
824  * there should be an option to enable doing this?
825  */
826  if (is_program)
827  return false;
828 
829  /*
830  * Get size of the file. (XXX if we fail here, would it be better to just
831  * return false to skip analyzing the table?)
832  */
833  if (stat(filename, &stat_buf) < 0)
834  ereport(ERROR,
836  errmsg("could not stat file \"%s\": %m",
837  filename)));
838 
839  /*
840  * Convert size to pages. Must return at least 1 so that we can tell
841  * later on that pg_class.relpages is not default.
842  */
843  *totalpages = (stat_buf.st_size + (BLCKSZ - 1)) / BLCKSZ;
844  if (*totalpages < 1)
845  *totalpages = 1;
846 
847  *func = file_acquire_sample_rows;
848 
849  return true;
850 }
int errcode_for_file_access(void)
Definition: elog.c:880
static int file_acquire_sample_rows(Relation onerel, int elevel, HeapTuple *rows, int targrows, double *totalrows, double *totaldeadrows)
Definition: file_fdw.c:1123
#define stat
Definition: win32_port.h:284

References ereport, errcode_for_file_access(), errmsg(), ERROR, file_acquire_sample_rows(), fileGetOptions(), filename, options, RelationGetRelid, stat::st_size, and stat.

Referenced by file_fdw_handler().

◆ fileBeginForeignScan()

static void fileBeginForeignScan ( ForeignScanState node,
int  eflags 
)
static

Definition at line 666 of file file_fdw.c.

667 {
668  ForeignScan *plan = (ForeignScan *) node->ss.ps.plan;
669  char *filename;
670  bool is_program;
671  List *options;
672  CopyFromState cstate;
673  FileFdwExecutionState *festate;
674 
675  /*
676  * Do nothing in EXPLAIN (no ANALYZE) case. node->fdw_state stays NULL.
677  */
678  if (eflags & EXEC_FLAG_EXPLAIN_ONLY)
679  return;
680 
681  /* Fetch options of foreign table */
683  &filename, &is_program, &options);
684 
685  /* Add any options from the plan (currently only convert_selectively) */
686  options = list_concat(options, plan->fdw_private);
687 
688  /*
689  * Create CopyState from FDW options. We always acquire all columns, so
690  * as to match the expected ScanTupleSlot signature.
691  */
692  cstate = BeginCopyFrom(NULL,
693  node->ss.ss_currentRelation,
694  NULL,
695  filename,
696  is_program,
697  NULL,
698  NIL,
699  options);
700 
701  /*
702  * Save state in node->fdw_state. We must save enough information to call
703  * BeginCopyFrom() again.
704  */
705  festate = (FileFdwExecutionState *) palloc(sizeof(FileFdwExecutionState));
706  festate->filename = filename;
707  festate->is_program = is_program;
708  festate->options = options;
709  festate->cstate = cstate;
710 
711  node->fdw_state = (void *) festate;
712 }
#define EXEC_FLAG_EXPLAIN_ONLY
Definition: executor.h:65
if(TABLE==NULL||TABLE_index==NULL)
Definition: isn.c:77
List * list_concat(List *list1, const List *list2)
Definition: list.c:561
#define plan(x)
Definition: pg_regress.c:162
ScanState ss
Definition: execnodes.h:2038
Plan * plan
Definition: execnodes.h:1117
Relation ss_currentRelation
Definition: execnodes.h:1565
PlanState ps
Definition: execnodes.h:1564

References BeginCopyFrom(), EXEC_FLAG_EXPLAIN_ONLY, ForeignScanState::fdw_state, fileGetOptions(), filename, if(), list_concat(), NIL, options, palloc(), PlanState::plan, plan, ScanState::ps, RelationGetRelid, ForeignScanState::ss, and ScanState::ss_currentRelation.

Referenced by file_fdw_handler().

◆ fileEndForeignScan()

static void fileEndForeignScan ( ForeignScanState node)
static

Definition at line 793 of file file_fdw.c.

794 {
796 
797  /* if festate is NULL, we are in EXPLAIN; nothing to do */
798  if (festate)
799  EndCopyFrom(festate->cstate);
800 }
CopyFromState cstate
Definition: file_fdw.c:110

References FileFdwExecutionState::cstate, EndCopyFrom(), ForeignScanState::fdw_state, and if().

Referenced by file_fdw_handler().

◆ fileExplainForeignScan()

static void fileExplainForeignScan ( ForeignScanState node,
ExplainState es 
)
static

Definition at line 634 of file file_fdw.c.

635 {
636  char *filename;
637  bool is_program;
638  List *options;
639 
640  /* Fetch options --- we only need filename and is_program at this point */
642  &filename, &is_program, &options);
643 
644  if (is_program)
645  ExplainPropertyText("Foreign Program", filename, es);
646  else
647  ExplainPropertyText("Foreign File", filename, es);
648 
649  /* Suppress file size if we're not showing cost details */
650  if (es->costs)
651  {
652  struct stat stat_buf;
653 
654  if (!is_program &&
655  stat(filename, &stat_buf) == 0)
656  ExplainPropertyInteger("Foreign File Size", "b",
657  (int64) stat_buf.st_size, es);
658  }
659 }
void ExplainPropertyText(const char *qlabel, const char *value, ExplainState *es)
Definition: explain.c:4801
void ExplainPropertyInteger(const char *qlabel, const char *unit, int64 value, ExplainState *es)
Definition: explain.c:4810
bool costs
Definition: explain.h:50

References ExplainState::costs, ExplainPropertyInteger(), ExplainPropertyText(), fileGetOptions(), filename, options, RelationGetRelid, ForeignScanState::ss, ScanState::ss_currentRelation, stat::st_size, and stat.

Referenced by file_fdw_handler().

◆ fileGetForeignPaths()

static void fileGetForeignPaths ( PlannerInfo root,
RelOptInfo baserel,
Oid  foreigntableid 
)
static

Definition at line 545 of file file_fdw.c.

548 {
549  FileFdwPlanState *fdw_private = (FileFdwPlanState *) baserel->fdw_private;
550  Cost startup_cost;
551  Cost total_cost;
552  List *columns;
553  List *coptions = NIL;
554 
555  /* Decide whether to selectively perform binary conversion */
557  foreigntableid,
558  &columns))
559  coptions = list_make1(makeDefElem("convert_selectively",
560  (Node *) columns, -1));
561 
562  /* Estimate costs */
563  estimate_costs(root, baserel, fdw_private,
564  &startup_cost, &total_cost);
565 
566  /*
567  * Create a ForeignPath node and add it as only possible path. We use the
568  * fdw_private list of the path to carry the convert_selectively option;
569  * it will be propagated into the fdw_private list of the Plan node.
570  *
571  * We don't support pushing join clauses into the quals of this path, but
572  * it could still have required parameterization due to LATERAL refs in
573  * its tlist.
574  */
575  add_path(baserel, (Path *)
576  create_foreignscan_path(root, baserel,
577  NULL, /* default pathtarget */
578  baserel->rows,
579  startup_cost,
580  total_cost,
581  NIL, /* no pathkeys */
582  baserel->lateral_relids,
583  NULL, /* no extra plan */
584  NIL, /* no fdw_restrictinfo list */
585  coptions));
586 
587  /*
588  * If data file was sorted, and we knew it somehow, we could insert
589  * appropriate pathkeys into the ForeignPath node to tell the planner
590  * that.
591  */
592 }
static bool check_selective_binary_conversion(RelOptInfo *baserel, Oid foreigntableid, List **columns)
Definition: file_fdw.c:874
static void estimate_costs(PlannerInfo *root, RelOptInfo *baserel, FileFdwPlanState *fdw_private, Cost *startup_cost, Cost *total_cost)
Definition: file_fdw.c:1080
DefElem * makeDefElem(char *name, Node *arg, int location)
Definition: makefuncs.c:564
ForeignPath * create_foreignscan_path(PlannerInfo *root, RelOptInfo *rel, PathTarget *target, double rows, Cost startup_cost, Cost total_cost, List *pathkeys, Relids required_outer, Path *fdw_outerpath, List *fdw_restrictinfo, List *fdw_private)
Definition: pathnode.c:2235
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:420
#define list_make1(x1)
Definition: pg_list.h:212
Relids lateral_relids
Definition: pathnodes.h:907

References add_path(), check_selective_binary_conversion(), create_foreignscan_path(), estimate_costs(), if(), RelOptInfo::lateral_relids, list_make1, makeDefElem(), NIL, root, and RelOptInfo::rows.

Referenced by file_fdw_handler().

◆ fileGetForeignPlan()

static ForeignScan * fileGetForeignPlan ( PlannerInfo root,
RelOptInfo baserel,
Oid  foreigntableid,
ForeignPath best_path,
List tlist,
List scan_clauses,
Plan outer_plan 
)
static

Definition at line 599 of file file_fdw.c.

606 {
607  Index scan_relid = baserel->relid;
608 
609  /*
610  * We have no native ability to evaluate restriction clauses, so we just
611  * put all the scan_clauses into the plan node's qual list for the
612  * executor to check. So all we have to do here is strip RestrictInfo
613  * nodes from the clauses and ignore pseudoconstants (which will be
614  * handled elsewhere).
615  */
616  scan_clauses = extract_actual_clauses(scan_clauses, false);
617 
618  /* Create the ForeignScan node */
619  return make_foreignscan(tlist,
620  scan_clauses,
621  scan_relid,
622  NIL, /* no expressions to evaluate */
623  best_path->fdw_private,
624  NIL, /* no custom tlist */
625  NIL, /* no remote quals */
626  outer_plan);
627 }
unsigned int Index
Definition: c.h:614
ForeignScan * make_foreignscan(List *qptlist, List *qpqual, Index scanrelid, List *fdw_exprs, List *fdw_private, List *fdw_scan_tlist, List *fdw_recheck_quals, Plan *outer_plan)
Definition: createplan.c:5822
List * extract_actual_clauses(List *restrictinfo_list, bool pseudoconstant)
Definition: restrictinfo.c:494
List * fdw_private
Definition: pathnodes.h:1872

References extract_actual_clauses(), ForeignPath::fdw_private, make_foreignscan(), NIL, and RelOptInfo::relid.

Referenced by file_fdw_handler().

◆ fileGetForeignRelSize()

static void fileGetForeignRelSize ( PlannerInfo root,
RelOptInfo baserel,
Oid  foreigntableid 
)
static

Definition at line 514 of file file_fdw.c.

517 {
518  FileFdwPlanState *fdw_private;
519 
520  /*
521  * Fetch options. We only need filename (or program) at this point, but
522  * we might as well get everything and not need to re-fetch it later in
523  * planning.
524  */
525  fdw_private = (FileFdwPlanState *) palloc(sizeof(FileFdwPlanState));
526  fileGetOptions(foreigntableid,
527  &fdw_private->filename,
528  &fdw_private->is_program,
529  &fdw_private->options);
530  baserel->fdw_private = (void *) fdw_private;
531 
532  /* Estimate relation size */
533  estimate_size(root, baserel, fdw_private);
534 }
static void estimate_size(PlannerInfo *root, RelOptInfo *baserel, FileFdwPlanState *fdw_private)
Definition: file_fdw.c:999
List * options
Definition: file_fdw.c:95

References estimate_size(), fileGetOptions(), FileFdwPlanState::filename, FileFdwPlanState::is_program, FileFdwPlanState::options, palloc(), and root.

Referenced by file_fdw_handler().

◆ fileGetOptions()

static void fileGetOptions ( Oid  foreigntableid,
char **  filename,
bool is_program,
List **  other_options 
)
static

Definition at line 370 of file file_fdw.c.

372 {
373  ForeignTable *table;
374  ForeignServer *server;
375  ForeignDataWrapper *wrapper;
376  List *options;
377  ListCell *lc;
378 
379  /*
380  * Extract options from FDW objects. We ignore user mappings because
381  * file_fdw doesn't have any options that can be specified there.
382  *
383  * (XXX Actually, given the current contents of valid_options[], there's
384  * no point in examining anything except the foreign table's own options.
385  * Simplify?)
386  */
387  table = GetForeignTable(foreigntableid);
388  server = GetForeignServer(table->serverid);
389  wrapper = GetForeignDataWrapper(server->fdwid);
390 
391  options = NIL;
392  options = list_concat(options, wrapper->options);
393  options = list_concat(options, server->options);
394  options = list_concat(options, table->options);
396 
397  /*
398  * Separate out the filename or program option (we assume there is only
399  * one).
400  */
401  *filename = NULL;
402  *is_program = false;
403  foreach(lc, options)
404  {
405  DefElem *def = (DefElem *) lfirst(lc);
406 
407  if (strcmp(def->defname, "filename") == 0)
408  {
409  *filename = defGetString(def);
411  break;
412  }
413  else if (strcmp(def->defname, "program") == 0)
414  {
415  *filename = defGetString(def);
416  *is_program = true;
418  break;
419  }
420  }
421 
422  /*
423  * The validator should have checked that filename or program was included
424  * in the options, but check again, just in case.
425  */
426  if (*filename == NULL)
427  elog(ERROR, "either filename or program is required for file_fdw foreign tables");
428 
429  *other_options = options;
430 }
#define elog(elevel,...)
Definition: elog.h:224
static List * get_file_fdw_attribute_options(Oid relid)
Definition: file_fdw.c:441
ForeignDataWrapper * GetForeignDataWrapper(Oid fdwid)
Definition: foreign.c:36
ForeignServer * GetForeignServer(Oid serverid)
Definition: foreign.c:110
#define foreach_delete_current(lst, var_or_cell)
Definition: pg_list.h:391
List * options
Definition: foreign.h:31
List * options
Definition: foreign.h:42
Oid serverid
Definition: foreign.h:56

References defGetString(), DefElem::defname, elog, ERROR, ForeignServer::fdwid, filename, foreach_delete_current, get_file_fdw_attribute_options(), GetForeignDataWrapper(), GetForeignServer(), GetForeignTable(), lfirst, list_concat(), NIL, options, ForeignDataWrapper::options, ForeignServer::options, ForeignTable::options, and ForeignTable::serverid.

Referenced by file_acquire_sample_rows(), fileAnalyzeForeignTable(), fileBeginForeignScan(), fileExplainForeignScan(), and fileGetForeignRelSize().

◆ fileIsForeignScanParallelSafe()

static bool fileIsForeignScanParallelSafe ( PlannerInfo root,
RelOptInfo rel,
RangeTblEntry rte 
)
static

Definition at line 858 of file file_fdw.c.

860 {
861  return true;
862 }

Referenced by file_fdw_handler().

◆ fileIterateForeignScan()

static TupleTableSlot * fileIterateForeignScan ( ForeignScanState node)
static

Definition at line 720 of file file_fdw.c.

721 {
723  EState *estate = CreateExecutorState();
724  ExprContext *econtext;
725  MemoryContext oldcontext;
726  TupleTableSlot *slot = node->ss.ss_ScanTupleSlot;
727  bool found;
728  ErrorContextCallback errcallback;
729 
730  /* Set up callback to identify error line number. */
731  errcallback.callback = CopyFromErrorCallback;
732  errcallback.arg = (void *) festate->cstate;
733  errcallback.previous = error_context_stack;
734  error_context_stack = &errcallback;
735 
736  /*
737  * The protocol for loading a virtual tuple into a slot is first
738  * ExecClearTuple, then fill the values/isnull arrays, then
739  * ExecStoreVirtualTuple. If we don't find another row in the file, we
740  * just skip the last step, leaving the slot empty as required.
741  *
742  * We pass ExprContext because there might be a use of the DEFAULT option
743  * in COPY FROM, so we may need to evaluate default expressions.
744  */
745  ExecClearTuple(slot);
746  econtext = GetPerTupleExprContext(estate);
747 
748  /*
749  * DEFAULT expressions need to be evaluated in a per-tuple context, so
750  * switch in case we are doing that.
751  */
752  oldcontext = MemoryContextSwitchTo(GetPerTupleMemoryContext(estate));
753  found = NextCopyFrom(festate->cstate, econtext,
754  slot->tts_values, slot->tts_isnull);
755  if (found)
756  ExecStoreVirtualTuple(slot);
757 
758  /* Switch back to original memory context */
759  MemoryContextSwitchTo(oldcontext);
760 
761  /* Remove error callback. */
762  error_context_stack = errcallback.previous;
763 
764  return slot;
765 }
TupleTableSlot * ExecStoreVirtualTuple(TupleTableSlot *slot)
Definition: execTuples.c:1639
EState * CreateExecutorState(void)
Definition: execUtils.c:88
#define GetPerTupleExprContext(estate)
Definition: executor.h:550
#define GetPerTupleMemoryContext(estate)
Definition: executor.h:555
TupleTableSlot * ss_ScanTupleSlot
Definition: execnodes.h:1567
bool * tts_isnull
Definition: tuptable.h:127
Datum * tts_values
Definition: tuptable.h:125
static TupleTableSlot * ExecClearTuple(TupleTableSlot *slot)
Definition: tuptable.h:454

References ErrorContextCallback::arg, ErrorContextCallback::callback, CopyFromErrorCallback(), CreateExecutorState(), FileFdwExecutionState::cstate, error_context_stack, ExecClearTuple(), ExecStoreVirtualTuple(), ForeignScanState::fdw_state, GetPerTupleExprContext, GetPerTupleMemoryContext, MemoryContextSwitchTo(), NextCopyFrom(), ErrorContextCallback::previous, ForeignScanState::ss, ScanState::ss_ScanTupleSlot, TupleTableSlot::tts_isnull, and TupleTableSlot::tts_values.

Referenced by file_fdw_handler().

◆ fileReScanForeignScan()

static void fileReScanForeignScan ( ForeignScanState node)
static

Definition at line 772 of file file_fdw.c.

773 {
775 
776  EndCopyFrom(festate->cstate);
777 
778  festate->cstate = BeginCopyFrom(NULL,
779  node->ss.ss_currentRelation,
780  NULL,
781  festate->filename,
782  festate->is_program,
783  NULL,
784  NIL,
785  festate->options);
786 }

References BeginCopyFrom(), FileFdwExecutionState::cstate, EndCopyFrom(), ForeignScanState::fdw_state, FileFdwExecutionState::filename, FileFdwExecutionState::is_program, NIL, FileFdwExecutionState::options, ForeignScanState::ss, and ScanState::ss_currentRelation.

Referenced by file_fdw_handler().

◆ get_file_fdw_attribute_options()

static List * get_file_fdw_attribute_options ( Oid  relid)
static

Definition at line 441 of file file_fdw.c.

442 {
443  Relation rel;
444  TupleDesc tupleDesc;
445  AttrNumber natts;
447  List *fnncolumns = NIL;
448  List *fncolumns = NIL;
449 
450  List *options = NIL;
451 
452  rel = table_open(relid, AccessShareLock);
453  tupleDesc = RelationGetDescr(rel);
454  natts = tupleDesc->natts;
455 
456  /* Retrieve FDW options for all user-defined attributes. */
457  for (attnum = 1; attnum <= natts; attnum++)
458  {
459  Form_pg_attribute attr = TupleDescAttr(tupleDesc, attnum - 1);
460  List *column_options;
461  ListCell *lc;
462 
463  /* Skip dropped attributes. */
464  if (attr->attisdropped)
465  continue;
466 
467  column_options = GetForeignColumnOptions(relid, attnum);
468  foreach(lc, column_options)
469  {
470  DefElem *def = (DefElem *) lfirst(lc);
471 
472  if (strcmp(def->defname, "force_not_null") == 0)
473  {
474  if (defGetBoolean(def))
475  {
476  char *attname = pstrdup(NameStr(attr->attname));
477 
478  fnncolumns = lappend(fnncolumns, makeString(attname));
479  }
480  }
481  else if (strcmp(def->defname, "force_null") == 0)
482  {
483  if (defGetBoolean(def))
484  {
485  char *attname = pstrdup(NameStr(attr->attname));
486 
487  fncolumns = lappend(fncolumns, makeString(attname));
488  }
489  }
490  /* maybe in future handle other column options here */
491  }
492  }
493 
495 
496  /*
497  * Return DefElem only when some column(s) have force_not_null /
498  * force_null options set
499  */
500  if (fnncolumns != NIL)
501  options = lappend(options, makeDefElem("force_not_null", (Node *) fnncolumns, -1));
502 
503  if (fncolumns != NIL)
504  options = lappend(options, makeDefElem("force_null", (Node *) fncolumns, -1));
505 
506  return options;
507 }
List * GetForeignColumnOptions(Oid relid, AttrNumber attnum)
Definition: foreign.c:291

References AccessShareLock, attname, attnum, defGetBoolean(), DefElem::defname, GetForeignColumnOptions(), lappend(), lfirst, makeDefElem(), makeString(), NameStr, TupleDescData::natts, NIL, options, pstrdup(), RelationGetDescr, table_close(), table_open(), and TupleDescAttr.

Referenced by fileGetOptions().

◆ is_valid_option()

static bool is_valid_option ( const char *  option,
Oid  context 
)
static

Definition at line 351 of file file_fdw.c.

352 {
353  const struct FileFdwOption *opt;
354 
355  for (opt = valid_options; opt->optname; opt++)
356  {
357  if (context == opt->optcontext && strcmp(opt->optname, option) == 0)
358  return true;
359  }
360  return false;
361 }
tree context
Definition: radixtree.h:1833

References context, FileFdwOption::optcontext, FileFdwOption::optname, and valid_options.

Referenced by file_fdw_validator().

◆ PG_FUNCTION_INFO_V1() [1/2]

PG_FUNCTION_INFO_V1 ( file_fdw_handler  )

◆ PG_FUNCTION_INFO_V1() [2/2]

PG_FUNCTION_INFO_V1 ( file_fdw_validator  )

Variable Documentation

◆ PG_MODULE_MAGIC

PG_MODULE_MAGIC

Definition at line 42 of file file_fdw.c.

◆ valid_options

const struct FileFdwOption valid_options[]
static
Initial value:
= {
{"filename", ForeignTableRelationId},
{"program", ForeignTableRelationId},
{"format", ForeignTableRelationId},
{"header", ForeignTableRelationId},
{"delimiter", ForeignTableRelationId},
{"quote", ForeignTableRelationId},
{"escape", ForeignTableRelationId},
{"null", ForeignTableRelationId},
{"default", ForeignTableRelationId},
{"encoding", ForeignTableRelationId},
{"force_not_null", AttributeRelationId},
{"force_null", AttributeRelationId},
{NULL, InvalidOid}
}
#define InvalidOid
Definition: postgres_ext.h:36

Definition at line 42 of file file_fdw.c.

Referenced by file_fdw_validator(), and is_valid_option().