Line data Source code
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) 2012-2025, 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_database.h"
43 : #include "catalog/pg_namespace.h"
44 : #include "catalog/pg_operator.h"
45 : #include "catalog/pg_opfamily.h"
46 : #include "catalog/pg_proc.h"
47 : #include "catalog/pg_ts_config.h"
48 : #include "catalog/pg_ts_dict.h"
49 : #include "catalog/pg_type.h"
50 : #include "commands/defrem.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 :
64 : /*
65 : * Global context for foreign_expr_walker's search of an expression tree.
66 : */
67 : typedef struct foreign_glob_cxt
68 : {
69 : PlannerInfo *root; /* global planner state */
70 : RelOptInfo *foreignrel; /* the foreign relation we are planning for */
71 : Relids relids; /* relids of base relations in the underlying
72 : * scan */
73 : } foreign_glob_cxt;
74 :
75 : /*
76 : * Local (per-tree-level) context for foreign_expr_walker's search.
77 : * This is concerned with identifying collations used in the expression.
78 : */
79 : typedef enum
80 : {
81 : FDW_COLLATE_NONE, /* expression is of a noncollatable type, or
82 : * it has default collation that is not
83 : * traceable to a foreign Var */
84 : FDW_COLLATE_SAFE, /* collation derives from a foreign Var */
85 : FDW_COLLATE_UNSAFE, /* collation is non-default and derives from
86 : * something other than a foreign Var */
87 : } FDWCollateState;
88 :
89 : typedef struct foreign_loc_cxt
90 : {
91 : Oid collation; /* OID of current collation, if any */
92 : FDWCollateState state; /* state of current collation choice */
93 : } foreign_loc_cxt;
94 :
95 : /*
96 : * Context for deparseExpr
97 : */
98 : typedef struct deparse_expr_cxt
99 : {
100 : PlannerInfo *root; /* global planner state */
101 : RelOptInfo *foreignrel; /* the foreign relation we are planning for */
102 : RelOptInfo *scanrel; /* the underlying scan relation. Same as
103 : * foreignrel, when that represents a join or
104 : * a base relation. */
105 : StringInfo buf; /* output buffer to append to */
106 : List **params_list; /* exprs that will become remote Params */
107 : } deparse_expr_cxt;
108 :
109 : #define REL_ALIAS_PREFIX "r"
110 : /* Handy macro to add relation name qualification */
111 : #define ADD_REL_QUALIFIER(buf, varno) \
112 : appendStringInfo((buf), "%s%d.", REL_ALIAS_PREFIX, (varno))
113 : #define SUBQUERY_REL_ALIAS_PREFIX "s"
114 : #define SUBQUERY_COL_ALIAS_PREFIX "c"
115 :
116 : /*
117 : * Functions to determine whether an expression can be evaluated safely on
118 : * remote server.
119 : */
120 : static bool foreign_expr_walker(Node *node,
121 : foreign_glob_cxt *glob_cxt,
122 : foreign_loc_cxt *outer_cxt,
123 : foreign_loc_cxt *case_arg_cxt);
124 : static char *deparse_type_name(Oid type_oid, int32 typemod);
125 :
126 : /*
127 : * Functions to construct string representation of a node tree.
128 : */
129 : static void deparseTargetList(StringInfo buf,
130 : RangeTblEntry *rte,
131 : Index rtindex,
132 : Relation rel,
133 : bool is_returning,
134 : Bitmapset *attrs_used,
135 : bool qualify_col,
136 : List **retrieved_attrs);
137 : static void deparseExplicitTargetList(List *tlist,
138 : bool is_returning,
139 : List **retrieved_attrs,
140 : deparse_expr_cxt *context);
141 : static void deparseSubqueryTargetList(deparse_expr_cxt *context);
142 : static void deparseReturningList(StringInfo buf, RangeTblEntry *rte,
143 : Index rtindex, Relation rel,
144 : bool trig_after_row,
145 : List *withCheckOptionList,
146 : List *returningList,
147 : List **retrieved_attrs);
148 : static void deparseColumnRef(StringInfo buf, int varno, int varattno,
149 : RangeTblEntry *rte, bool qualify_col);
150 : static void deparseRelation(StringInfo buf, Relation rel);
151 : static void deparseExpr(Expr *node, deparse_expr_cxt *context);
152 : static void deparseVar(Var *node, deparse_expr_cxt *context);
153 : static void deparseConst(Const *node, deparse_expr_cxt *context, int showtype);
154 : static void deparseParam(Param *node, deparse_expr_cxt *context);
155 : static void deparseSubscriptingRef(SubscriptingRef *node, deparse_expr_cxt *context);
156 : static void deparseFuncExpr(FuncExpr *node, deparse_expr_cxt *context);
157 : static void deparseOpExpr(OpExpr *node, deparse_expr_cxt *context);
158 : static bool isPlainForeignVar(Expr *node, deparse_expr_cxt *context);
159 : static void deparseOperatorName(StringInfo buf, Form_pg_operator opform);
160 : static void deparseDistinctExpr(DistinctExpr *node, deparse_expr_cxt *context);
161 : static void deparseScalarArrayOpExpr(ScalarArrayOpExpr *node,
162 : deparse_expr_cxt *context);
163 : static void deparseRelabelType(RelabelType *node, deparse_expr_cxt *context);
164 : static void deparseArrayCoerceExpr(ArrayCoerceExpr *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);
180 : static void deparseFromExprForRel(StringInfo buf, PlannerInfo *root,
181 : RelOptInfo *foreignrel, bool use_alias,
182 : Index ignore_rel, List **ignore_conds,
183 : List **additional_conds,
184 : List **params_list);
185 : static void appendWhereClause(List *exprs, List *additional_conds,
186 : deparse_expr_cxt *context);
187 : static void deparseFromExpr(List *quals, deparse_expr_cxt *context);
188 : static void deparseRangeTblRef(StringInfo buf, PlannerInfo *root,
189 : RelOptInfo *foreignrel, bool make_subquery,
190 : Index ignore_rel, List **ignore_conds,
191 : List **additional_conds, List **params_list);
192 : static void deparseAggref(Aggref *node, deparse_expr_cxt *context);
193 : static void appendGroupByClause(List *tlist, deparse_expr_cxt *context);
194 : static void appendOrderBySuffix(Oid sortop, Oid sortcoltype, bool nulls_first,
195 : deparse_expr_cxt *context);
196 : static void appendAggOrderBy(List *orderList, List *targetList,
197 : deparse_expr_cxt *context);
198 : static void appendFunctionName(Oid funcid, deparse_expr_cxt *context);
199 : static Node *deparseSortGroupClause(Index ref, List *tlist, bool force_colno,
200 : deparse_expr_cxt *context);
201 :
202 : /*
203 : * Helper functions
204 : */
205 : static bool is_subquery_var(Var *node, RelOptInfo *foreignrel,
206 : int *relno, int *colno);
207 : static void get_relation_column_alias_ids(Var *node, RelOptInfo *foreignrel,
208 : int *relno, int *colno);
209 :
210 :
211 : /*
212 : * Examine each qual clause in input_conds, and classify them into two groups,
213 : * which are returned as two lists:
214 : * - remote_conds contains expressions that can be evaluated remotely
215 : * - local_conds contains expressions that can't be evaluated remotely
216 : */
217 : void
218 4908 : classifyConditions(PlannerInfo *root,
219 : RelOptInfo *baserel,
220 : List *input_conds,
221 : List **remote_conds,
222 : List **local_conds)
223 : {
224 : ListCell *lc;
225 :
226 4908 : *remote_conds = NIL;
227 4908 : *local_conds = NIL;
228 :
229 6404 : foreach(lc, input_conds)
230 : {
231 1496 : RestrictInfo *ri = lfirst_node(RestrictInfo, lc);
232 :
233 1496 : if (is_foreign_expr(root, baserel, ri->clause))
234 1330 : *remote_conds = lappend(*remote_conds, ri);
235 : else
236 166 : *local_conds = lappend(*local_conds, ri);
237 : }
238 4908 : }
239 :
240 : /*
241 : * Returns true if given expr is safe to evaluate on the foreign server.
242 : */
243 : bool
244 7518 : is_foreign_expr(PlannerInfo *root,
245 : RelOptInfo *baserel,
246 : Expr *expr)
247 : {
248 : foreign_glob_cxt glob_cxt;
249 : foreign_loc_cxt loc_cxt;
250 7518 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) (baserel->fdw_private);
251 :
252 : /*
253 : * Check that the expression consists of nodes that are safe to execute
254 : * remotely.
255 : */
256 7518 : glob_cxt.root = root;
257 7518 : glob_cxt.foreignrel = baserel;
258 :
259 : /*
260 : * For an upper relation, use relids from its underneath scan relation,
261 : * because the upperrel's own relids currently aren't set to anything
262 : * meaningful by the core code. For other relation, use their own relids.
263 : */
264 7518 : if (IS_UPPER_REL(baserel))
265 906 : glob_cxt.relids = fpinfo->outerrel->relids;
266 : else
267 6612 : glob_cxt.relids = baserel->relids;
268 7518 : loc_cxt.collation = InvalidOid;
269 7518 : loc_cxt.state = FDW_COLLATE_NONE;
270 7518 : if (!foreign_expr_walker((Node *) expr, &glob_cxt, &loc_cxt, NULL))
271 300 : return false;
272 :
273 : /*
274 : * If the expression has a valid collation that does not arise from a
275 : * foreign var, the expression can not be sent over.
276 : */
277 7218 : if (loc_cxt.state == FDW_COLLATE_UNSAFE)
278 4 : return false;
279 :
280 : /*
281 : * An expression which includes any mutable functions can't be sent over
282 : * because its result is not stable. For example, sending now() remote
283 : * side could cause confusion from clock offsets. Future versions might
284 : * be able to make this choice with more granularity. (We check this last
285 : * because it requires a lot of expensive catalog lookups.)
286 : */
287 7214 : if (contain_mutable_functions((Node *) expr))
288 48 : return false;
289 :
290 : /* OK to evaluate on the remote server */
291 7166 : return true;
292 : }
293 :
294 : /*
295 : * Check if expression is safe to execute remotely, and return true if so.
296 : *
297 : * In addition, *outer_cxt is updated with collation information.
298 : *
299 : * case_arg_cxt is NULL if this subexpression is not inside a CASE-with-arg.
300 : * Otherwise, it points to the collation info derived from the arg expression,
301 : * which must be consulted by any CaseTestExpr.
302 : *
303 : * We must check that the expression contains only node types we can deparse,
304 : * that all types/functions/operators are safe to send (they are "shippable"),
305 : * and that all collations used in the expression derive from Vars of the
306 : * foreign table. Because of the latter, the logic is pretty close to
307 : * assign_collations_walker() in parse_collate.c, though we can assume here
308 : * that the given expression is valid. Note function mutability is not
309 : * currently considered here.
310 : */
311 : static bool
312 18756 : foreign_expr_walker(Node *node,
313 : foreign_glob_cxt *glob_cxt,
314 : foreign_loc_cxt *outer_cxt,
315 : foreign_loc_cxt *case_arg_cxt)
316 : {
317 18756 : bool check_type = true;
318 : PgFdwRelationInfo *fpinfo;
319 : foreign_loc_cxt inner_cxt;
320 : Oid collation;
321 : FDWCollateState state;
322 :
323 : /* Need do nothing for empty subexpressions */
324 18756 : if (node == NULL)
325 660 : return true;
326 :
327 : /* May need server info from baserel's fdw_private struct */
328 18096 : fpinfo = (PgFdwRelationInfo *) (glob_cxt->foreignrel->fdw_private);
329 :
330 : /* Set up inner_cxt for possible recursion to child nodes */
331 18096 : inner_cxt.collation = InvalidOid;
332 18096 : inner_cxt.state = FDW_COLLATE_NONE;
333 :
334 18096 : switch (nodeTag(node))
335 : {
336 8358 : case T_Var:
337 : {
338 8358 : Var *var = (Var *) node;
339 :
340 : /*
341 : * If the Var is from the foreign table, we consider its
342 : * collation (if any) safe to use. If it is from another
343 : * table, we treat its collation the same way as we would a
344 : * Param's collation, ie it's not safe for it to have a
345 : * non-default collation.
346 : */
347 8358 : if (bms_is_member(var->varno, glob_cxt->relids) &&
348 7472 : var->varlevelsup == 0)
349 : {
350 : /* Var belongs to foreign table */
351 :
352 : /*
353 : * System columns other than ctid should not be sent to
354 : * the remote, since we don't make any effort to ensure
355 : * that local and remote values match (tableoid, in
356 : * particular, almost certainly doesn't match).
357 : */
358 7472 : if (var->varattno < 0 &&
359 20 : var->varattno != SelfItemPointerAttributeNumber)
360 16 : return false;
361 :
362 : /* Else check the collation */
363 7456 : collation = var->varcollid;
364 7456 : state = OidIsValid(collation) ? FDW_COLLATE_SAFE : FDW_COLLATE_NONE;
365 : }
366 : else
367 : {
368 : /* Var belongs to some other table */
369 886 : collation = var->varcollid;
370 886 : if (collation == InvalidOid ||
371 : collation == DEFAULT_COLLATION_OID)
372 : {
373 : /*
374 : * It's noncollatable, or it's safe to combine with a
375 : * collatable foreign Var, so set state to NONE.
376 : */
377 886 : state = FDW_COLLATE_NONE;
378 : }
379 : else
380 : {
381 : /*
382 : * Do not fail right away, since the Var might appear
383 : * in a collation-insensitive context.
384 : */
385 0 : state = FDW_COLLATE_UNSAFE;
386 : }
387 : }
388 : }
389 8342 : break;
390 1852 : case T_Const:
391 : {
392 1852 : Const *c = (Const *) node;
393 :
394 : /*
395 : * Constants of regproc and related types can't be shipped
396 : * unless the referenced object is shippable. But NULL's ok.
397 : * (See also the related code in dependency.c.)
398 : */
399 1852 : if (!c->constisnull)
400 : {
401 1834 : switch (c->consttype)
402 : {
403 0 : case REGPROCOID:
404 : case REGPROCEDUREOID:
405 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
406 : ProcedureRelationId, fpinfo))
407 0 : return false;
408 0 : break;
409 0 : case REGOPEROID:
410 : case REGOPERATOROID:
411 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
412 : OperatorRelationId, fpinfo))
413 0 : return false;
414 0 : break;
415 0 : case REGCLASSOID:
416 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
417 : RelationRelationId, fpinfo))
418 0 : return false;
419 0 : break;
420 0 : case REGTYPEOID:
421 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
422 : TypeRelationId, fpinfo))
423 0 : return false;
424 0 : break;
425 0 : case REGCOLLATIONOID:
426 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
427 : CollationRelationId, fpinfo))
428 0 : return false;
429 0 : break;
430 8 : case REGCONFIGOID:
431 :
432 : /*
433 : * For text search objects only, we weaken the
434 : * normal shippability criterion to allow all OIDs
435 : * below FirstNormalObjectId. Without this, none
436 : * of the initdb-installed TS configurations would
437 : * be shippable, which would be quite annoying.
438 : */
439 8 : if (DatumGetObjectId(c->constvalue) >= FirstNormalObjectId &&
440 8 : !is_shippable(DatumGetObjectId(c->constvalue),
441 : TSConfigRelationId, fpinfo))
442 4 : return false;
443 4 : break;
444 0 : case REGDICTIONARYOID:
445 0 : if (DatumGetObjectId(c->constvalue) >= FirstNormalObjectId &&
446 0 : !is_shippable(DatumGetObjectId(c->constvalue),
447 : TSDictionaryRelationId, fpinfo))
448 0 : return false;
449 0 : break;
450 0 : case REGNAMESPACEOID:
451 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
452 : NamespaceRelationId, fpinfo))
453 0 : return false;
454 0 : break;
455 0 : case REGROLEOID:
456 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
457 : AuthIdRelationId, fpinfo))
458 0 : return false;
459 0 : break;
460 0 : case REGDATABASEOID:
461 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
462 : DatabaseRelationId, fpinfo))
463 0 : return false;
464 0 : break;
465 : }
466 : }
467 :
468 : /*
469 : * If the constant has nondefault collation, either it's of a
470 : * non-builtin type, or it reflects folding of a CollateExpr.
471 : * It's unsafe to send to the remote unless it's used in a
472 : * non-collation-sensitive context.
473 : */
474 1848 : collation = c->constcollid;
475 1848 : if (collation == InvalidOid ||
476 : collation == DEFAULT_COLLATION_OID)
477 1844 : state = FDW_COLLATE_NONE;
478 : else
479 4 : state = FDW_COLLATE_UNSAFE;
480 : }
481 1848 : break;
482 52 : case T_Param:
483 : {
484 52 : Param *p = (Param *) node;
485 :
486 : /*
487 : * If it's a MULTIEXPR Param, punt. We can't tell from here
488 : * whether the referenced sublink/subplan contains any remote
489 : * Vars; if it does, handling that is too complicated to
490 : * consider supporting at present. Fortunately, MULTIEXPR
491 : * Params are not reduced to plain PARAM_EXEC until the end of
492 : * planning, so we can easily detect this case. (Normal
493 : * PARAM_EXEC Params are safe to ship because their values
494 : * come from somewhere else in the plan tree; but a MULTIEXPR
495 : * references a sub-select elsewhere in the same targetlist,
496 : * so we'd be on the hook to evaluate it somehow if we wanted
497 : * to handle such cases as direct foreign updates.)
498 : */
499 52 : if (p->paramkind == PARAM_MULTIEXPR)
500 6 : return false;
501 :
502 : /*
503 : * Collation rule is same as for Consts and non-foreign Vars.
504 : */
505 46 : collation = p->paramcollid;
506 46 : if (collation == InvalidOid ||
507 : collation == DEFAULT_COLLATION_OID)
508 46 : state = FDW_COLLATE_NONE;
509 : else
510 0 : state = FDW_COLLATE_UNSAFE;
511 : }
512 46 : break;
513 2 : case T_SubscriptingRef:
514 : {
515 2 : SubscriptingRef *sr = (SubscriptingRef *) node;
516 :
517 : /* Assignment should not be in restrictions. */
518 2 : if (sr->refassgnexpr != NULL)
519 0 : return false;
520 :
521 : /*
522 : * Recurse into the remaining subexpressions. The container
523 : * subscripts will not affect collation of the SubscriptingRef
524 : * result, so do those first and reset inner_cxt afterwards.
525 : */
526 2 : if (!foreign_expr_walker((Node *) sr->refupperindexpr,
527 : glob_cxt, &inner_cxt, case_arg_cxt))
528 0 : return false;
529 2 : inner_cxt.collation = InvalidOid;
530 2 : inner_cxt.state = FDW_COLLATE_NONE;
531 2 : if (!foreign_expr_walker((Node *) sr->reflowerindexpr,
532 : glob_cxt, &inner_cxt, case_arg_cxt))
533 0 : return false;
534 2 : inner_cxt.collation = InvalidOid;
535 2 : inner_cxt.state = FDW_COLLATE_NONE;
536 2 : if (!foreign_expr_walker((Node *) sr->refexpr,
537 : glob_cxt, &inner_cxt, case_arg_cxt))
538 0 : return false;
539 :
540 : /*
541 : * Container subscripting typically yields same collation as
542 : * refexpr's, but in case it doesn't, use same logic as for
543 : * function nodes.
544 : */
545 2 : collation = sr->refcollid;
546 2 : if (collation == InvalidOid)
547 2 : state = FDW_COLLATE_NONE;
548 0 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
549 0 : collation == inner_cxt.collation)
550 0 : state = FDW_COLLATE_SAFE;
551 0 : else if (collation == DEFAULT_COLLATION_OID)
552 0 : state = FDW_COLLATE_NONE;
553 : else
554 0 : state = FDW_COLLATE_UNSAFE;
555 : }
556 2 : break;
557 268 : case T_FuncExpr:
558 : {
559 268 : FuncExpr *fe = (FuncExpr *) node;
560 :
561 : /*
562 : * If function used by the expression is not shippable, it
563 : * can't be sent to remote because it might have incompatible
564 : * semantics on remote side.
565 : */
566 268 : if (!is_shippable(fe->funcid, ProcedureRelationId, fpinfo))
567 16 : return false;
568 :
569 : /*
570 : * Recurse to input subexpressions.
571 : */
572 252 : if (!foreign_expr_walker((Node *) fe->args,
573 : glob_cxt, &inner_cxt, case_arg_cxt))
574 26 : return false;
575 :
576 : /*
577 : * If function's input collation is not derived from a foreign
578 : * Var, it can't be sent to remote.
579 : */
580 226 : if (fe->inputcollid == InvalidOid)
581 : /* OK, inputs are all noncollatable */ ;
582 66 : else if (inner_cxt.state != FDW_COLLATE_SAFE ||
583 40 : fe->inputcollid != inner_cxt.collation)
584 26 : return false;
585 :
586 : /*
587 : * Detect whether node is introducing a collation not derived
588 : * from a foreign Var. (If so, we just mark it unsafe for now
589 : * rather than immediately returning false, since the parent
590 : * node might not care.)
591 : */
592 200 : collation = fe->funccollid;
593 200 : if (collation == InvalidOid)
594 162 : state = FDW_COLLATE_NONE;
595 38 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
596 36 : collation == inner_cxt.collation)
597 36 : state = FDW_COLLATE_SAFE;
598 2 : else if (collation == DEFAULT_COLLATION_OID)
599 0 : state = FDW_COLLATE_NONE;
600 : else
601 2 : state = FDW_COLLATE_UNSAFE;
602 : }
603 200 : break;
604 3184 : case T_OpExpr:
605 : case T_DistinctExpr: /* struct-equivalent to OpExpr */
606 : {
607 3184 : OpExpr *oe = (OpExpr *) node;
608 :
609 : /*
610 : * Similarly, only shippable operators can be sent to remote.
611 : * (If the operator is shippable, we assume its underlying
612 : * function is too.)
613 : */
614 3184 : if (!is_shippable(oe->opno, OperatorRelationId, fpinfo))
615 94 : return false;
616 :
617 : /*
618 : * Recurse to input subexpressions.
619 : */
620 3090 : if (!foreign_expr_walker((Node *) oe->args,
621 : glob_cxt, &inner_cxt, case_arg_cxt))
622 126 : return false;
623 :
624 : /*
625 : * If operator's input collation is not derived from a foreign
626 : * Var, it can't be sent to remote.
627 : */
628 2964 : if (oe->inputcollid == InvalidOid)
629 : /* OK, inputs are all noncollatable */ ;
630 138 : else if (inner_cxt.state != FDW_COLLATE_SAFE ||
631 126 : oe->inputcollid != inner_cxt.collation)
632 12 : return false;
633 :
634 : /* Result-collation handling is same as for functions */
635 2952 : collation = oe->opcollid;
636 2952 : if (collation == InvalidOid)
637 2924 : state = FDW_COLLATE_NONE;
638 28 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
639 28 : collation == inner_cxt.collation)
640 28 : state = FDW_COLLATE_SAFE;
641 0 : else if (collation == DEFAULT_COLLATION_OID)
642 0 : state = FDW_COLLATE_NONE;
643 : else
644 0 : state = FDW_COLLATE_UNSAFE;
645 : }
646 2952 : break;
647 8 : case T_ScalarArrayOpExpr:
648 : {
649 8 : ScalarArrayOpExpr *oe = (ScalarArrayOpExpr *) node;
650 :
651 : /*
652 : * Again, only shippable operators can be sent to remote.
653 : */
654 8 : if (!is_shippable(oe->opno, OperatorRelationId, fpinfo))
655 0 : return false;
656 :
657 : /*
658 : * Recurse to input subexpressions.
659 : */
660 8 : if (!foreign_expr_walker((Node *) oe->args,
661 : glob_cxt, &inner_cxt, case_arg_cxt))
662 0 : return false;
663 :
664 : /*
665 : * If operator's input collation is not derived from a foreign
666 : * Var, it can't be sent to remote.
667 : */
668 8 : if (oe->inputcollid == InvalidOid)
669 : /* OK, inputs are all noncollatable */ ;
670 2 : else if (inner_cxt.state != FDW_COLLATE_SAFE ||
671 2 : oe->inputcollid != inner_cxt.collation)
672 0 : return false;
673 :
674 : /* Output is always boolean and so noncollatable. */
675 8 : collation = InvalidOid;
676 8 : state = FDW_COLLATE_NONE;
677 : }
678 8 : break;
679 138 : case T_RelabelType:
680 : {
681 138 : RelabelType *r = (RelabelType *) node;
682 :
683 : /*
684 : * Recurse to input subexpression.
685 : */
686 138 : if (!foreign_expr_walker((Node *) r->arg,
687 : glob_cxt, &inner_cxt, case_arg_cxt))
688 0 : return false;
689 :
690 : /*
691 : * RelabelType must not introduce a collation not derived from
692 : * an input foreign Var (same logic as for a real function).
693 : */
694 138 : collation = r->resultcollid;
695 138 : if (collation == InvalidOid)
696 0 : state = FDW_COLLATE_NONE;
697 138 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
698 130 : collation == inner_cxt.collation)
699 118 : state = FDW_COLLATE_SAFE;
700 20 : else if (collation == DEFAULT_COLLATION_OID)
701 6 : state = FDW_COLLATE_NONE;
702 : else
703 14 : state = FDW_COLLATE_UNSAFE;
704 : }
705 138 : break;
706 2 : case T_ArrayCoerceExpr:
707 : {
708 2 : ArrayCoerceExpr *e = (ArrayCoerceExpr *) node;
709 :
710 : /*
711 : * Recurse to input subexpression.
712 : */
713 2 : if (!foreign_expr_walker((Node *) e->arg,
714 : glob_cxt, &inner_cxt, case_arg_cxt))
715 0 : return false;
716 :
717 : /*
718 : * T_ArrayCoerceExpr must not introduce a collation not
719 : * derived from an input foreign Var (same logic as for a
720 : * function).
721 : */
722 2 : collation = e->resultcollid;
723 2 : if (collation == InvalidOid)
724 0 : state = FDW_COLLATE_NONE;
725 2 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
726 0 : collation == inner_cxt.collation)
727 0 : state = FDW_COLLATE_SAFE;
728 2 : else if (collation == DEFAULT_COLLATION_OID)
729 2 : state = FDW_COLLATE_NONE;
730 : else
731 0 : state = FDW_COLLATE_UNSAFE;
732 : }
733 2 : break;
734 72 : case T_BoolExpr:
735 : {
736 72 : BoolExpr *b = (BoolExpr *) node;
737 :
738 : /*
739 : * Recurse to input subexpressions.
740 : */
741 72 : if (!foreign_expr_walker((Node *) b->args,
742 : glob_cxt, &inner_cxt, case_arg_cxt))
743 0 : return false;
744 :
745 : /* Output is always boolean and so noncollatable. */
746 72 : collation = InvalidOid;
747 72 : state = FDW_COLLATE_NONE;
748 : }
749 72 : break;
750 54 : case T_NullTest:
751 : {
752 54 : NullTest *nt = (NullTest *) node;
753 :
754 : /*
755 : * Recurse to input subexpressions.
756 : */
757 54 : if (!foreign_expr_walker((Node *) nt->arg,
758 : glob_cxt, &inner_cxt, case_arg_cxt))
759 0 : return false;
760 :
761 : /* Output is always boolean and so noncollatable. */
762 54 : collation = InvalidOid;
763 54 : state = FDW_COLLATE_NONE;
764 : }
765 54 : break;
766 26 : case T_CaseExpr:
767 : {
768 26 : CaseExpr *ce = (CaseExpr *) node;
769 : foreign_loc_cxt arg_cxt;
770 : foreign_loc_cxt tmp_cxt;
771 : ListCell *lc;
772 :
773 : /*
774 : * Recurse to CASE's arg expression, if any. Its collation
775 : * has to be saved aside for use while examining CaseTestExprs
776 : * within the WHEN expressions.
777 : */
778 26 : arg_cxt.collation = InvalidOid;
779 26 : arg_cxt.state = FDW_COLLATE_NONE;
780 26 : if (ce->arg)
781 : {
782 14 : if (!foreign_expr_walker((Node *) ce->arg,
783 : glob_cxt, &arg_cxt, case_arg_cxt))
784 2 : return false;
785 : }
786 :
787 : /* Examine the CaseWhen subexpressions. */
788 58 : foreach(lc, ce->args)
789 : {
790 34 : CaseWhen *cw = lfirst_node(CaseWhen, lc);
791 :
792 34 : if (ce->arg)
793 : {
794 : /*
795 : * In a CASE-with-arg, the parser should have produced
796 : * WHEN clauses of the form "CaseTestExpr = RHS",
797 : * possibly with an implicit coercion inserted above
798 : * the CaseTestExpr. However in an expression that's
799 : * been through the optimizer, the WHEN clause could
800 : * be almost anything (since the equality operator
801 : * could have been expanded into an inline function).
802 : * In such cases forbid pushdown, because
803 : * deparseCaseExpr can't handle it.
804 : */
805 22 : Node *whenExpr = (Node *) cw->expr;
806 : List *opArgs;
807 :
808 22 : if (!IsA(whenExpr, OpExpr))
809 2 : return false;
810 :
811 22 : opArgs = ((OpExpr *) whenExpr)->args;
812 22 : if (list_length(opArgs) != 2 ||
813 22 : !IsA(strip_implicit_coercions(linitial(opArgs)),
814 : CaseTestExpr))
815 0 : return false;
816 : }
817 :
818 : /*
819 : * Recurse to WHEN expression, passing down the arg info.
820 : * Its collation doesn't affect the result (really, it
821 : * should be boolean and thus not have a collation).
822 : */
823 34 : tmp_cxt.collation = InvalidOid;
824 34 : tmp_cxt.state = FDW_COLLATE_NONE;
825 34 : if (!foreign_expr_walker((Node *) cw->expr,
826 : glob_cxt, &tmp_cxt, &arg_cxt))
827 2 : return false;
828 :
829 : /* Recurse to THEN expression. */
830 32 : if (!foreign_expr_walker((Node *) cw->result,
831 : glob_cxt, &inner_cxt, case_arg_cxt))
832 0 : return false;
833 : }
834 :
835 : /* Recurse to ELSE expression. */
836 24 : if (!foreign_expr_walker((Node *) ce->defresult,
837 : glob_cxt, &inner_cxt, case_arg_cxt))
838 0 : return false;
839 :
840 : /*
841 : * Detect whether node is introducing a collation not derived
842 : * from a foreign Var. (If so, we just mark it unsafe for now
843 : * rather than immediately returning false, since the parent
844 : * node might not care.) This is the same as for function
845 : * nodes, except that the input collation is derived from only
846 : * the THEN and ELSE subexpressions.
847 : */
848 24 : collation = ce->casecollid;
849 24 : if (collation == InvalidOid)
850 24 : state = FDW_COLLATE_NONE;
851 0 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
852 0 : collation == inner_cxt.collation)
853 0 : state = FDW_COLLATE_SAFE;
854 0 : else if (collation == DEFAULT_COLLATION_OID)
855 0 : state = FDW_COLLATE_NONE;
856 : else
857 0 : state = FDW_COLLATE_UNSAFE;
858 : }
859 24 : break;
860 22 : case T_CaseTestExpr:
861 : {
862 22 : CaseTestExpr *c = (CaseTestExpr *) node;
863 :
864 : /* Punt if we seem not to be inside a CASE arg WHEN. */
865 22 : if (!case_arg_cxt)
866 0 : return false;
867 :
868 : /*
869 : * Otherwise, any nondefault collation attached to the
870 : * CaseTestExpr node must be derived from foreign Var(s) in
871 : * the CASE arg.
872 : */
873 22 : collation = c->collation;
874 22 : if (collation == InvalidOid)
875 16 : state = FDW_COLLATE_NONE;
876 6 : else if (case_arg_cxt->state == FDW_COLLATE_SAFE &&
877 4 : collation == case_arg_cxt->collation)
878 4 : state = FDW_COLLATE_SAFE;
879 2 : else if (collation == DEFAULT_COLLATION_OID)
880 0 : state = FDW_COLLATE_NONE;
881 : else
882 2 : state = FDW_COLLATE_UNSAFE;
883 : }
884 22 : break;
885 8 : case T_ArrayExpr:
886 : {
887 8 : ArrayExpr *a = (ArrayExpr *) node;
888 :
889 : /*
890 : * Recurse to input subexpressions.
891 : */
892 8 : if (!foreign_expr_walker((Node *) a->elements,
893 : glob_cxt, &inner_cxt, case_arg_cxt))
894 0 : return false;
895 :
896 : /*
897 : * ArrayExpr must not introduce a collation not derived from
898 : * an input foreign Var (same logic as for a function).
899 : */
900 8 : collation = a->array_collid;
901 8 : if (collation == InvalidOid)
902 8 : state = FDW_COLLATE_NONE;
903 0 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
904 0 : collation == inner_cxt.collation)
905 0 : state = FDW_COLLATE_SAFE;
906 0 : else if (collation == DEFAULT_COLLATION_OID)
907 0 : state = FDW_COLLATE_NONE;
908 : else
909 0 : state = FDW_COLLATE_UNSAFE;
910 : }
911 8 : break;
912 3430 : case T_List:
913 : {
914 3430 : List *l = (List *) node;
915 : ListCell *lc;
916 :
917 : /*
918 : * Recurse to component subexpressions.
919 : */
920 9770 : foreach(lc, l)
921 : {
922 6518 : if (!foreign_expr_walker((Node *) lfirst(lc),
923 : glob_cxt, &inner_cxt, case_arg_cxt))
924 178 : return false;
925 : }
926 :
927 : /*
928 : * When processing a list, collation state just bubbles up
929 : * from the list elements.
930 : */
931 3252 : collation = inner_cxt.collation;
932 3252 : state = inner_cxt.state;
933 :
934 : /* Don't apply exprType() to the list. */
935 3252 : check_type = false;
936 : }
937 3252 : break;
938 560 : case T_Aggref:
939 : {
940 560 : Aggref *agg = (Aggref *) node;
941 : ListCell *lc;
942 :
943 : /* Not safe to pushdown when not in grouping context */
944 560 : if (!IS_UPPER_REL(glob_cxt->foreignrel))
945 0 : return false;
946 :
947 : /* Only non-split aggregates are pushable. */
948 560 : if (agg->aggsplit != AGGSPLIT_SIMPLE)
949 0 : return false;
950 :
951 : /* As usual, it must be shippable. */
952 560 : if (!is_shippable(agg->aggfnoid, ProcedureRelationId, fpinfo))
953 8 : return false;
954 :
955 : /*
956 : * Recurse to input args. aggdirectargs, aggorder and
957 : * aggdistinct are all present in args, so no need to check
958 : * their shippability explicitly.
959 : */
960 994 : foreach(lc, agg->args)
961 : {
962 466 : Node *n = (Node *) lfirst(lc);
963 :
964 : /* If TargetEntry, extract the expression from it */
965 466 : if (IsA(n, TargetEntry))
966 : {
967 466 : TargetEntry *tle = (TargetEntry *) n;
968 :
969 466 : n = (Node *) tle->expr;
970 : }
971 :
972 466 : if (!foreign_expr_walker(n,
973 : glob_cxt, &inner_cxt, case_arg_cxt))
974 24 : return false;
975 : }
976 :
977 : /*
978 : * For aggorder elements, check whether the sort operator, if
979 : * specified, is shippable or not.
980 : */
981 528 : if (agg->aggorder)
982 : {
983 140 : foreach(lc, agg->aggorder)
984 : {
985 76 : SortGroupClause *srt = (SortGroupClause *) lfirst(lc);
986 : Oid sortcoltype;
987 : TypeCacheEntry *typentry;
988 : TargetEntry *tle;
989 :
990 76 : tle = get_sortgroupref_tle(srt->tleSortGroupRef,
991 : agg->args);
992 76 : sortcoltype = exprType((Node *) tle->expr);
993 76 : typentry = lookup_type_cache(sortcoltype,
994 : TYPECACHE_LT_OPR | TYPECACHE_GT_OPR);
995 : /* Check shippability of non-default sort operator. */
996 76 : if (srt->sortop != typentry->lt_opr &&
997 28 : srt->sortop != typentry->gt_opr &&
998 12 : !is_shippable(srt->sortop, OperatorRelationId,
999 : fpinfo))
1000 8 : return false;
1001 : }
1002 : }
1003 :
1004 : /* Check aggregate filter */
1005 520 : if (!foreign_expr_walker((Node *) agg->aggfilter,
1006 : glob_cxt, &inner_cxt, case_arg_cxt))
1007 4 : return false;
1008 :
1009 : /*
1010 : * If aggregate's input collation is not derived from a
1011 : * foreign Var, it can't be sent to remote.
1012 : */
1013 516 : if (agg->inputcollid == InvalidOid)
1014 : /* OK, inputs are all noncollatable */ ;
1015 44 : else if (inner_cxt.state != FDW_COLLATE_SAFE ||
1016 44 : agg->inputcollid != inner_cxt.collation)
1017 0 : return false;
1018 :
1019 : /*
1020 : * Detect whether node is introducing a collation not derived
1021 : * from a foreign Var. (If so, we just mark it unsafe for now
1022 : * rather than immediately returning false, since the parent
1023 : * node might not care.)
1024 : */
1025 516 : collation = agg->aggcollid;
1026 516 : if (collation == InvalidOid)
1027 514 : state = FDW_COLLATE_NONE;
1028 2 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
1029 2 : collation == inner_cxt.collation)
1030 2 : state = FDW_COLLATE_SAFE;
1031 0 : else if (collation == DEFAULT_COLLATION_OID)
1032 0 : state = FDW_COLLATE_NONE;
1033 : else
1034 0 : state = FDW_COLLATE_UNSAFE;
1035 : }
1036 516 : break;
1037 60 : default:
1038 :
1039 : /*
1040 : * If it's anything else, assume it's unsafe. This list can be
1041 : * expanded later, but don't forget to add deparse support below.
1042 : */
1043 60 : return false;
1044 : }
1045 :
1046 : /*
1047 : * If result type of given expression is not shippable, it can't be sent
1048 : * to remote because it might have incompatible semantics on remote side.
1049 : */
1050 17486 : if (check_type && !is_shippable(exprType(node), TypeRelationId, fpinfo))
1051 50 : return false;
1052 :
1053 : /*
1054 : * Now, merge my collation information into my parent's state.
1055 : */
1056 17436 : if (state > outer_cxt->state)
1057 : {
1058 : /* Override previous parent state */
1059 966 : outer_cxt->collation = collation;
1060 966 : outer_cxt->state = state;
1061 : }
1062 16470 : else if (state == outer_cxt->state)
1063 : {
1064 : /* Merge, or detect error if there's a collation conflict */
1065 16366 : switch (state)
1066 : {
1067 16342 : case FDW_COLLATE_NONE:
1068 : /* Nothing + nothing is still nothing */
1069 16342 : break;
1070 22 : case FDW_COLLATE_SAFE:
1071 22 : if (collation != outer_cxt->collation)
1072 : {
1073 : /*
1074 : * Non-default collation always beats default.
1075 : */
1076 0 : if (outer_cxt->collation == DEFAULT_COLLATION_OID)
1077 : {
1078 : /* Override previous parent state */
1079 0 : outer_cxt->collation = collation;
1080 : }
1081 0 : else if (collation != DEFAULT_COLLATION_OID)
1082 : {
1083 : /*
1084 : * Conflict; show state as indeterminate. We don't
1085 : * want to "return false" right away, since parent
1086 : * node might not care about collation.
1087 : */
1088 0 : outer_cxt->state = FDW_COLLATE_UNSAFE;
1089 : }
1090 : }
1091 22 : break;
1092 2 : case FDW_COLLATE_UNSAFE:
1093 : /* We're still conflicted ... */
1094 2 : break;
1095 : }
1096 : }
1097 :
1098 : /* It looks OK */
1099 17436 : return true;
1100 : }
1101 :
1102 : /*
1103 : * Returns true if given expr is something we'd have to send the value of
1104 : * to the foreign server.
1105 : *
1106 : * This should return true when the expression is a shippable node that
1107 : * deparseExpr would add to context->params_list. Note that we don't care
1108 : * if the expression *contains* such a node, only whether one appears at top
1109 : * level. We need this to detect cases where setrefs.c would recognize a
1110 : * false match between an fdw_exprs item (which came from the params_list)
1111 : * and an entry in fdw_scan_tlist (which we're considering putting the given
1112 : * expression into).
1113 : */
1114 : bool
1115 552 : is_foreign_param(PlannerInfo *root,
1116 : RelOptInfo *baserel,
1117 : Expr *expr)
1118 : {
1119 552 : if (expr == NULL)
1120 0 : return false;
1121 :
1122 552 : switch (nodeTag(expr))
1123 : {
1124 152 : case T_Var:
1125 : {
1126 : /* It would have to be sent unless it's a foreign Var */
1127 152 : Var *var = (Var *) expr;
1128 152 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) (baserel->fdw_private);
1129 : Relids relids;
1130 :
1131 152 : if (IS_UPPER_REL(baserel))
1132 152 : relids = fpinfo->outerrel->relids;
1133 : else
1134 0 : relids = baserel->relids;
1135 :
1136 152 : if (bms_is_member(var->varno, relids) && var->varlevelsup == 0)
1137 152 : return false; /* foreign Var, so not a param */
1138 : else
1139 0 : return true; /* it'd have to be a param */
1140 : break;
1141 : }
1142 8 : case T_Param:
1143 : /* Params always have to be sent to the foreign server */
1144 8 : return true;
1145 392 : default:
1146 392 : break;
1147 : }
1148 392 : return false;
1149 : }
1150 :
1151 : /*
1152 : * Returns true if it's safe to push down the sort expression described by
1153 : * 'pathkey' to the foreign server.
1154 : */
1155 : bool
1156 1550 : is_foreign_pathkey(PlannerInfo *root,
1157 : RelOptInfo *baserel,
1158 : PathKey *pathkey)
1159 : {
1160 1550 : EquivalenceClass *pathkey_ec = pathkey->pk_eclass;
1161 1550 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) baserel->fdw_private;
1162 :
1163 : /*
1164 : * is_foreign_expr would detect volatile expressions as well, but checking
1165 : * ec_has_volatile here saves some cycles.
1166 : */
1167 1550 : if (pathkey_ec->ec_has_volatile)
1168 8 : return false;
1169 :
1170 : /* can't push down the sort if the pathkey's opfamily is not shippable */
1171 1542 : if (!is_shippable(pathkey->pk_opfamily, OperatorFamilyRelationId, fpinfo))
1172 6 : return false;
1173 :
1174 : /* can push if a suitable EC member exists */
1175 1536 : return (find_em_for_rel(root, pathkey_ec, baserel) != NULL);
1176 : }
1177 :
1178 : /*
1179 : * Convert type OID + typmod info into a type name we can ship to the remote
1180 : * server. Someplace else had better have verified that this type name is
1181 : * expected to be known on the remote end.
1182 : *
1183 : * This is almost just format_type_with_typemod(), except that if left to its
1184 : * own devices, that function will make schema-qualification decisions based
1185 : * on the local search_path, which is wrong. We must schema-qualify all
1186 : * type names that are not in pg_catalog. We assume here that built-in types
1187 : * are all in pg_catalog and need not be qualified; otherwise, qualify.
1188 : */
1189 : static char *
1190 1090 : deparse_type_name(Oid type_oid, int32 typemod)
1191 : {
1192 1090 : bits16 flags = FORMAT_TYPE_TYPEMOD_GIVEN;
1193 :
1194 1090 : if (!is_builtin(type_oid))
1195 0 : flags |= FORMAT_TYPE_FORCE_QUALIFY;
1196 :
1197 1090 : return format_type_extended(type_oid, typemod, flags);
1198 : }
1199 :
1200 : /*
1201 : * Build the targetlist for given relation to be deparsed as SELECT clause.
1202 : *
1203 : * The output targetlist contains the columns that need to be fetched from the
1204 : * foreign server for the given relation. If foreignrel is an upper relation,
1205 : * then the output targetlist can also contain expressions to be evaluated on
1206 : * foreign server.
1207 : */
1208 : List *
1209 1604 : build_tlist_to_deparse(RelOptInfo *foreignrel)
1210 : {
1211 1604 : List *tlist = NIL;
1212 1604 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1213 : ListCell *lc;
1214 :
1215 : /*
1216 : * For an upper relation, we have already built the target list while
1217 : * checking shippability, so just return that.
1218 : */
1219 1604 : if (IS_UPPER_REL(foreignrel))
1220 332 : return fpinfo->grouped_tlist;
1221 :
1222 : /*
1223 : * We require columns specified in foreignrel->reltarget->exprs and those
1224 : * required for evaluating the local conditions.
1225 : */
1226 1272 : tlist = add_to_flat_tlist(tlist,
1227 1272 : pull_var_clause((Node *) foreignrel->reltarget->exprs,
1228 : PVC_RECURSE_PLACEHOLDERS));
1229 1320 : foreach(lc, fpinfo->local_conds)
1230 : {
1231 48 : RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
1232 :
1233 48 : tlist = add_to_flat_tlist(tlist,
1234 48 : pull_var_clause((Node *) rinfo->clause,
1235 : PVC_RECURSE_PLACEHOLDERS));
1236 : }
1237 :
1238 1272 : return tlist;
1239 : }
1240 :
1241 : /*
1242 : * Deparse SELECT statement for given relation into buf.
1243 : *
1244 : * tlist contains the list of desired columns to be fetched from foreign server.
1245 : * For a base relation fpinfo->attrs_used is used to construct SELECT clause,
1246 : * hence the tlist is ignored for a base relation.
1247 : *
1248 : * remote_conds is the list of conditions to be deparsed into the WHERE clause
1249 : * (or, in the case of upper relations, into the HAVING clause).
1250 : *
1251 : * If params_list is not NULL, it receives a list of Params and other-relation
1252 : * Vars used in the clauses; these values must be transmitted to the remote
1253 : * server as parameter values.
1254 : *
1255 : * If params_list is NULL, we're generating the query for EXPLAIN purposes,
1256 : * so Params and other-relation Vars should be replaced by dummy values.
1257 : *
1258 : * pathkeys is the list of pathkeys to order the result by.
1259 : *
1260 : * is_subquery is the flag to indicate whether to deparse the specified
1261 : * relation as a subquery.
1262 : *
1263 : * List of columns selected is returned in retrieved_attrs.
1264 : */
1265 : void
1266 4636 : deparseSelectStmtForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *rel,
1267 : List *tlist, List *remote_conds, List *pathkeys,
1268 : bool has_final_sort, bool has_limit, bool is_subquery,
1269 : List **retrieved_attrs, List **params_list)
1270 : {
1271 : deparse_expr_cxt context;
1272 4636 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) rel->fdw_private;
1273 : List *quals;
1274 :
1275 : /*
1276 : * We handle relations for foreign tables, joins between those and upper
1277 : * relations.
1278 : */
1279 : Assert(IS_JOIN_REL(rel) || IS_SIMPLE_REL(rel) || IS_UPPER_REL(rel));
1280 :
1281 : /* Fill portions of context common to upper, join and base relation */
1282 4636 : context.buf = buf;
1283 4636 : context.root = root;
1284 4636 : context.foreignrel = rel;
1285 4636 : context.scanrel = IS_UPPER_REL(rel) ? fpinfo->outerrel : rel;
1286 4636 : context.params_list = params_list;
1287 :
1288 : /* Construct SELECT clause */
1289 4636 : deparseSelectSql(tlist, is_subquery, retrieved_attrs, &context);
1290 :
1291 : /*
1292 : * For upper relations, the WHERE clause is built from the remote
1293 : * conditions of the underlying scan relation; otherwise, we can use the
1294 : * supplied list of remote conditions directly.
1295 : */
1296 4636 : if (IS_UPPER_REL(rel))
1297 332 : {
1298 : PgFdwRelationInfo *ofpinfo;
1299 :
1300 332 : ofpinfo = (PgFdwRelationInfo *) fpinfo->outerrel->fdw_private;
1301 332 : quals = ofpinfo->remote_conds;
1302 : }
1303 : else
1304 4304 : quals = remote_conds;
1305 :
1306 : /* Construct FROM and WHERE clauses */
1307 4636 : deparseFromExpr(quals, &context);
1308 :
1309 4636 : if (IS_UPPER_REL(rel))
1310 : {
1311 : /* Append GROUP BY clause */
1312 332 : appendGroupByClause(tlist, &context);
1313 :
1314 : /* Append HAVING clause */
1315 332 : if (remote_conds)
1316 : {
1317 36 : appendStringInfoString(buf, " HAVING ");
1318 36 : appendConditions(remote_conds, &context);
1319 : }
1320 : }
1321 :
1322 : /* Add ORDER BY clause if we found any useful pathkeys */
1323 4636 : if (pathkeys)
1324 1474 : appendOrderByClause(pathkeys, has_final_sort, &context);
1325 :
1326 : /* Add LIMIT clause if necessary */
1327 4636 : if (has_limit)
1328 292 : appendLimitClause(&context);
1329 :
1330 : /* Add any necessary FOR UPDATE/SHARE. */
1331 4636 : deparseLockingClause(&context);
1332 4636 : }
1333 :
1334 : /*
1335 : * Construct a simple SELECT statement that retrieves desired columns
1336 : * of the specified foreign table, and append it to "buf". The output
1337 : * contains just "SELECT ... ".
1338 : *
1339 : * We also create an integer List of the columns being retrieved, which is
1340 : * returned to *retrieved_attrs, unless we deparse the specified relation
1341 : * as a subquery.
1342 : *
1343 : * tlist is the list of desired columns. is_subquery is the flag to
1344 : * indicate whether to deparse the specified relation as a subquery.
1345 : * Read prologue of deparseSelectStmtForRel() for details.
1346 : */
1347 : static void
1348 4636 : deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_attrs,
1349 : deparse_expr_cxt *context)
1350 : {
1351 4636 : StringInfo buf = context->buf;
1352 4636 : RelOptInfo *foreignrel = context->foreignrel;
1353 4636 : PlannerInfo *root = context->root;
1354 4636 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1355 :
1356 : /*
1357 : * Construct SELECT list
1358 : */
1359 4636 : appendStringInfoString(buf, "SELECT ");
1360 :
1361 4636 : if (is_subquery)
1362 : {
1363 : /*
1364 : * For a relation that is deparsed as a subquery, emit expressions
1365 : * specified in the relation's reltarget. Note that since this is for
1366 : * the subquery, no need to care about *retrieved_attrs.
1367 : */
1368 100 : deparseSubqueryTargetList(context);
1369 : }
1370 4536 : else if (IS_JOIN_REL(foreignrel) || IS_UPPER_REL(foreignrel))
1371 : {
1372 : /*
1373 : * For a join or upper relation the input tlist gives the list of
1374 : * columns required to be fetched from the foreign server.
1375 : */
1376 1604 : deparseExplicitTargetList(tlist, false, retrieved_attrs, context);
1377 : }
1378 : else
1379 : {
1380 : /*
1381 : * For a base relation fpinfo->attrs_used gives the list of columns
1382 : * required to be fetched from the foreign server.
1383 : */
1384 2932 : RangeTblEntry *rte = planner_rt_fetch(foreignrel->relid, root);
1385 :
1386 : /*
1387 : * Core code already has some lock on each rel being planned, so we
1388 : * can use NoLock here.
1389 : */
1390 2932 : Relation rel = table_open(rte->relid, NoLock);
1391 :
1392 2932 : deparseTargetList(buf, rte, foreignrel->relid, rel, false,
1393 : fpinfo->attrs_used, false, retrieved_attrs);
1394 2932 : table_close(rel, NoLock);
1395 : }
1396 4636 : }
1397 :
1398 : /*
1399 : * Construct a FROM clause and, if needed, a WHERE clause, and append those to
1400 : * "buf".
1401 : *
1402 : * quals is the list of clauses to be included in the WHERE clause.
1403 : * (These may or may not include RestrictInfo decoration.)
1404 : */
1405 : static void
1406 4636 : deparseFromExpr(List *quals, deparse_expr_cxt *context)
1407 : {
1408 4636 : StringInfo buf = context->buf;
1409 4636 : RelOptInfo *scanrel = context->scanrel;
1410 4636 : List *additional_conds = NIL;
1411 :
1412 : /* For upper relations, scanrel must be either a joinrel or a baserel */
1413 : Assert(!IS_UPPER_REL(context->foreignrel) ||
1414 : IS_JOIN_REL(scanrel) || IS_SIMPLE_REL(scanrel));
1415 :
1416 : /* Construct FROM clause */
1417 4636 : appendStringInfoString(buf, " FROM ");
1418 4636 : deparseFromExprForRel(buf, context->root, scanrel,
1419 4636 : (bms_membership(scanrel->relids) == BMS_MULTIPLE),
1420 : (Index) 0, NULL, &additional_conds,
1421 : context->params_list);
1422 4636 : appendWhereClause(quals, additional_conds, context);
1423 4636 : if (additional_conds != NIL)
1424 316 : list_free_deep(additional_conds);
1425 4636 : }
1426 :
1427 : /*
1428 : * Emit a target list that retrieves the columns specified in attrs_used.
1429 : * This is used for both SELECT and RETURNING targetlists; the is_returning
1430 : * parameter is true only for a RETURNING targetlist.
1431 : *
1432 : * The tlist text is appended to buf, and we also create an integer List
1433 : * of the columns being retrieved, which is returned to *retrieved_attrs.
1434 : *
1435 : * If qualify_col is true, add relation alias before the column name.
1436 : */
1437 : static void
1438 3700 : deparseTargetList(StringInfo buf,
1439 : RangeTblEntry *rte,
1440 : Index rtindex,
1441 : Relation rel,
1442 : bool is_returning,
1443 : Bitmapset *attrs_used,
1444 : bool qualify_col,
1445 : List **retrieved_attrs)
1446 : {
1447 3700 : TupleDesc tupdesc = RelationGetDescr(rel);
1448 : bool have_wholerow;
1449 : bool first;
1450 : int i;
1451 :
1452 3700 : *retrieved_attrs = NIL;
1453 :
1454 : /* If there's a whole-row reference, we'll need all the columns. */
1455 3700 : have_wholerow = bms_is_member(0 - FirstLowInvalidHeapAttributeNumber,
1456 : attrs_used);
1457 :
1458 3700 : first = true;
1459 26702 : for (i = 1; i <= tupdesc->natts; i++)
1460 : {
1461 23002 : Form_pg_attribute attr = TupleDescAttr(tupdesc, i - 1);
1462 :
1463 : /* Ignore dropped attributes. */
1464 23002 : if (attr->attisdropped)
1465 2074 : continue;
1466 :
1467 35048 : if (have_wholerow ||
1468 14120 : bms_is_member(i - FirstLowInvalidHeapAttributeNumber,
1469 : attrs_used))
1470 : {
1471 13030 : if (!first)
1472 9574 : appendStringInfoString(buf, ", ");
1473 3456 : else if (is_returning)
1474 224 : appendStringInfoString(buf, " RETURNING ");
1475 13030 : first = false;
1476 :
1477 13030 : deparseColumnRef(buf, rtindex, i, rte, qualify_col);
1478 :
1479 13030 : *retrieved_attrs = lappend_int(*retrieved_attrs, i);
1480 : }
1481 : }
1482 :
1483 : /*
1484 : * Add ctid if needed. We currently don't support retrieving any other
1485 : * system columns.
1486 : */
1487 3700 : if (bms_is_member(SelfItemPointerAttributeNumber - FirstLowInvalidHeapAttributeNumber,
1488 : attrs_used))
1489 : {
1490 600 : if (!first)
1491 456 : appendStringInfoString(buf, ", ");
1492 144 : else if (is_returning)
1493 0 : appendStringInfoString(buf, " RETURNING ");
1494 600 : first = false;
1495 :
1496 600 : if (qualify_col)
1497 0 : ADD_REL_QUALIFIER(buf, rtindex);
1498 600 : appendStringInfoString(buf, "ctid");
1499 :
1500 600 : *retrieved_attrs = lappend_int(*retrieved_attrs,
1501 : SelfItemPointerAttributeNumber);
1502 : }
1503 :
1504 : /* Don't generate bad syntax if no undropped columns */
1505 3700 : if (first && !is_returning)
1506 88 : appendStringInfoString(buf, "NULL");
1507 3700 : }
1508 :
1509 : /*
1510 : * Deparse the appropriate locking clause (FOR UPDATE or FOR SHARE) for a
1511 : * given relation (context->scanrel).
1512 : */
1513 : static void
1514 4636 : deparseLockingClause(deparse_expr_cxt *context)
1515 : {
1516 4636 : StringInfo buf = context->buf;
1517 4636 : PlannerInfo *root = context->root;
1518 4636 : RelOptInfo *rel = context->scanrel;
1519 4636 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) rel->fdw_private;
1520 4636 : int relid = -1;
1521 :
1522 11656 : while ((relid = bms_next_member(rel->relids, relid)) >= 0)
1523 : {
1524 : /*
1525 : * Ignore relation if it appears in a lower subquery. Locking clause
1526 : * for such a relation is included in the subquery if necessary.
1527 : */
1528 7020 : if (bms_is_member(relid, fpinfo->lower_subquery_rels))
1529 160 : continue;
1530 :
1531 : /*
1532 : * Add FOR UPDATE/SHARE if appropriate. We apply locking during the
1533 : * initial row fetch, rather than later on as is done for local
1534 : * tables. The extra roundtrips involved in trying to duplicate the
1535 : * local semantics exactly don't seem worthwhile (see also comments
1536 : * for RowMarkType).
1537 : *
1538 : * Note: because we actually run the query as a cursor, this assumes
1539 : * that DECLARE CURSOR ... FOR UPDATE is supported, which it isn't
1540 : * before 8.3.
1541 : */
1542 6860 : if (bms_is_member(relid, root->all_result_relids) &&
1543 618 : (root->parse->commandType == CMD_UPDATE ||
1544 248 : root->parse->commandType == CMD_DELETE))
1545 : {
1546 : /* Relation is UPDATE/DELETE target, so use FOR UPDATE */
1547 614 : appendStringInfoString(buf, " FOR UPDATE");
1548 :
1549 : /* Add the relation alias if we are here for a join relation */
1550 614 : if (IS_JOIN_REL(rel))
1551 108 : appendStringInfo(buf, " OF %s%d", REL_ALIAS_PREFIX, relid);
1552 : }
1553 : else
1554 : {
1555 6246 : PlanRowMark *rc = get_plan_rowmark(root->rowMarks, relid);
1556 :
1557 6246 : if (rc)
1558 : {
1559 : /*
1560 : * Relation is specified as a FOR UPDATE/SHARE target, so
1561 : * handle that. (But we could also see LCS_NONE, meaning this
1562 : * isn't a target relation after all.)
1563 : *
1564 : * For now, just ignore any [NO] KEY specification, since (a)
1565 : * it's not clear what that means for a remote table that we
1566 : * don't have complete information about, and (b) it wouldn't
1567 : * work anyway on older remote servers. Likewise, we don't
1568 : * worry about NOWAIT.
1569 : */
1570 720 : switch (rc->strength)
1571 : {
1572 392 : case LCS_NONE:
1573 : /* No locking needed */
1574 392 : break;
1575 76 : case LCS_FORKEYSHARE:
1576 : case LCS_FORSHARE:
1577 76 : appendStringInfoString(buf, " FOR SHARE");
1578 76 : break;
1579 252 : case LCS_FORNOKEYUPDATE:
1580 : case LCS_FORUPDATE:
1581 252 : appendStringInfoString(buf, " FOR UPDATE");
1582 252 : break;
1583 : }
1584 :
1585 : /* Add the relation alias if we are here for a join relation */
1586 720 : if (bms_membership(rel->relids) == BMS_MULTIPLE &&
1587 424 : rc->strength != LCS_NONE)
1588 220 : appendStringInfo(buf, " OF %s%d", REL_ALIAS_PREFIX, relid);
1589 : }
1590 : }
1591 : }
1592 4636 : }
1593 :
1594 : /*
1595 : * Deparse conditions from the provided list and append them to buf.
1596 : *
1597 : * The conditions in the list are assumed to be ANDed. This function is used to
1598 : * deparse WHERE clauses, JOIN .. ON clauses and HAVING clauses.
1599 : *
1600 : * Depending on the caller, the list elements might be either RestrictInfos
1601 : * or bare clauses.
1602 : */
1603 : static void
1604 3802 : appendConditions(List *exprs, deparse_expr_cxt *context)
1605 : {
1606 : int nestlevel;
1607 : ListCell *lc;
1608 3802 : bool is_first = true;
1609 3802 : StringInfo buf = context->buf;
1610 :
1611 : /* Make sure any constants in the exprs are printed portably */
1612 3802 : nestlevel = set_transmission_modes();
1613 :
1614 8722 : foreach(lc, exprs)
1615 : {
1616 4920 : Expr *expr = (Expr *) lfirst(lc);
1617 :
1618 : /* Extract clause from RestrictInfo, if required */
1619 4920 : if (IsA(expr, RestrictInfo))
1620 4202 : expr = ((RestrictInfo *) expr)->clause;
1621 :
1622 : /* Connect expressions with "AND" and parenthesize each condition. */
1623 4920 : if (!is_first)
1624 1118 : appendStringInfoString(buf, " AND ");
1625 :
1626 4920 : appendStringInfoChar(buf, '(');
1627 4920 : deparseExpr(expr, context);
1628 4920 : appendStringInfoChar(buf, ')');
1629 :
1630 4920 : is_first = false;
1631 : }
1632 :
1633 3802 : reset_transmission_modes(nestlevel);
1634 3802 : }
1635 :
1636 : /*
1637 : * Append WHERE clause, containing conditions from exprs and additional_conds,
1638 : * to context->buf.
1639 : */
1640 : static void
1641 5224 : appendWhereClause(List *exprs, List *additional_conds, deparse_expr_cxt *context)
1642 : {
1643 5224 : StringInfo buf = context->buf;
1644 5224 : bool need_and = false;
1645 : ListCell *lc;
1646 :
1647 5224 : if (exprs != NIL || additional_conds != NIL)
1648 2492 : appendStringInfoString(buf, " WHERE ");
1649 :
1650 : /*
1651 : * If there are some filters, append them.
1652 : */
1653 5224 : if (exprs != NIL)
1654 : {
1655 2286 : appendConditions(exprs, context);
1656 2286 : need_and = true;
1657 : }
1658 :
1659 : /*
1660 : * If there are some EXISTS conditions, coming from SEMI-JOINS, append
1661 : * them.
1662 : */
1663 5604 : foreach(lc, additional_conds)
1664 : {
1665 380 : if (need_and)
1666 174 : appendStringInfoString(buf, " AND ");
1667 380 : appendStringInfoString(buf, (char *) lfirst(lc));
1668 380 : need_and = true;
1669 : }
1670 5224 : }
1671 :
1672 : /* Output join name for given join type */
1673 : const char *
1674 2190 : get_jointype_name(JoinType jointype)
1675 : {
1676 2190 : switch (jointype)
1677 : {
1678 1454 : case JOIN_INNER:
1679 1454 : return "INNER";
1680 :
1681 432 : case JOIN_LEFT:
1682 432 : return "LEFT";
1683 :
1684 0 : case JOIN_RIGHT:
1685 0 : return "RIGHT";
1686 :
1687 216 : case JOIN_FULL:
1688 216 : return "FULL";
1689 :
1690 88 : case JOIN_SEMI:
1691 88 : return "SEMI";
1692 :
1693 0 : default:
1694 : /* Shouldn't come here, but protect from buggy code. */
1695 0 : elog(ERROR, "unsupported join type %d", jointype);
1696 : }
1697 :
1698 : /* Keep compiler happy */
1699 : return NULL;
1700 : }
1701 :
1702 : /*
1703 : * Deparse given targetlist and append it to context->buf.
1704 : *
1705 : * tlist is list of TargetEntry's which in turn contain Var nodes.
1706 : *
1707 : * retrieved_attrs is the list of continuously increasing integers starting
1708 : * from 1. It has same number of entries as tlist.
1709 : *
1710 : * This is used for both SELECT and RETURNING targetlists; the is_returning
1711 : * parameter is true only for a RETURNING targetlist.
1712 : */
1713 : static void
1714 1620 : deparseExplicitTargetList(List *tlist,
1715 : bool is_returning,
1716 : List **retrieved_attrs,
1717 : deparse_expr_cxt *context)
1718 : {
1719 : ListCell *lc;
1720 1620 : StringInfo buf = context->buf;
1721 1620 : int i = 0;
1722 :
1723 1620 : *retrieved_attrs = NIL;
1724 :
1725 9568 : foreach(lc, tlist)
1726 : {
1727 7948 : TargetEntry *tle = lfirst_node(TargetEntry, lc);
1728 :
1729 7948 : if (i > 0)
1730 6344 : appendStringInfoString(buf, ", ");
1731 1604 : else if (is_returning)
1732 4 : appendStringInfoString(buf, " RETURNING ");
1733 :
1734 7948 : deparseExpr((Expr *) tle->expr, context);
1735 :
1736 7948 : *retrieved_attrs = lappend_int(*retrieved_attrs, i + 1);
1737 7948 : i++;
1738 : }
1739 :
1740 1620 : if (i == 0 && !is_returning)
1741 4 : appendStringInfoString(buf, "NULL");
1742 1620 : }
1743 :
1744 : /*
1745 : * Emit expressions specified in the given relation's reltarget.
1746 : *
1747 : * This is used for deparsing the given relation as a subquery.
1748 : */
1749 : static void
1750 100 : deparseSubqueryTargetList(deparse_expr_cxt *context)
1751 : {
1752 100 : StringInfo buf = context->buf;
1753 100 : RelOptInfo *foreignrel = context->foreignrel;
1754 : bool first;
1755 : ListCell *lc;
1756 :
1757 : /* Should only be called in these cases. */
1758 : Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
1759 :
1760 100 : first = true;
1761 240 : foreach(lc, foreignrel->reltarget->exprs)
1762 : {
1763 140 : Node *node = (Node *) lfirst(lc);
1764 :
1765 140 : if (!first)
1766 48 : appendStringInfoString(buf, ", ");
1767 140 : first = false;
1768 :
1769 140 : deparseExpr((Expr *) node, context);
1770 : }
1771 :
1772 : /* Don't generate bad syntax if no expressions */
1773 100 : if (first)
1774 8 : appendStringInfoString(buf, "NULL");
1775 100 : }
1776 :
1777 : /*
1778 : * Construct FROM clause for given relation
1779 : *
1780 : * The function constructs ... JOIN ... ON ... for join relation. For a base
1781 : * relation it just returns schema-qualified tablename, with the appropriate
1782 : * alias if so requested.
1783 : *
1784 : * 'ignore_rel' is either zero or the RT index of a target relation. In the
1785 : * latter case the function constructs FROM clause of UPDATE or USING clause
1786 : * of DELETE; it deparses the join relation as if the relation never contained
1787 : * the target relation, and creates a List of conditions to be deparsed into
1788 : * the top-level WHERE clause, which is returned to *ignore_conds.
1789 : *
1790 : * 'additional_conds' is a pointer to a list of strings to be appended to
1791 : * the WHERE clause, coming from lower-level SEMI-JOINs.
1792 : */
1793 : static void
1794 8376 : deparseFromExprForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
1795 : bool use_alias, Index ignore_rel, List **ignore_conds,
1796 : List **additional_conds, List **params_list)
1797 : {
1798 8376 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1799 :
1800 8376 : if (IS_JOIN_REL(foreignrel))
1801 1904 : {
1802 : StringInfoData join_sql_o;
1803 : StringInfoData join_sql_i;
1804 1920 : RelOptInfo *outerrel = fpinfo->outerrel;
1805 1920 : RelOptInfo *innerrel = fpinfo->innerrel;
1806 1920 : bool outerrel_is_target = false;
1807 1920 : bool innerrel_is_target = false;
1808 1920 : List *additional_conds_i = NIL;
1809 1920 : List *additional_conds_o = NIL;
1810 :
1811 1920 : if (ignore_rel > 0 && bms_is_member(ignore_rel, foreignrel->relids))
1812 : {
1813 : /*
1814 : * If this is an inner join, add joinclauses to *ignore_conds and
1815 : * set it to empty so that those can be deparsed into the WHERE
1816 : * clause. Note that since the target relation can never be
1817 : * within the nullable side of an outer join, those could safely
1818 : * be pulled up into the WHERE clause (see foreign_join_ok()).
1819 : * Note also that since the target relation is only inner-joined
1820 : * to any other relation in the query, all conditions in the join
1821 : * tree mentioning the target relation could be deparsed into the
1822 : * WHERE clause by doing this recursively.
1823 : */
1824 24 : if (fpinfo->jointype == JOIN_INNER)
1825 : {
1826 40 : *ignore_conds = list_concat(*ignore_conds,
1827 20 : fpinfo->joinclauses);
1828 20 : fpinfo->joinclauses = NIL;
1829 : }
1830 :
1831 : /*
1832 : * Check if either of the input relations is the target relation.
1833 : */
1834 24 : if (outerrel->relid == ignore_rel)
1835 16 : outerrel_is_target = true;
1836 8 : else if (innerrel->relid == ignore_rel)
1837 0 : innerrel_is_target = true;
1838 : }
1839 :
1840 : /* Deparse outer relation if not the target relation. */
1841 1920 : if (!outerrel_is_target)
1842 : {
1843 1904 : initStringInfo(&join_sql_o);
1844 1904 : deparseRangeTblRef(&join_sql_o, root, outerrel,
1845 1904 : fpinfo->make_outerrel_subquery,
1846 : ignore_rel, ignore_conds, &additional_conds_o,
1847 : params_list);
1848 :
1849 : /*
1850 : * If inner relation is the target relation, skip deparsing it.
1851 : * Note that since the join of the target relation with any other
1852 : * relation in the query is an inner join and can never be within
1853 : * the nullable side of an outer join, the join could be
1854 : * interchanged with higher-level joins (cf. identity 1 on outer
1855 : * join reordering shown in src/backend/optimizer/README), which
1856 : * means it's safe to skip the target-relation deparsing here.
1857 : */
1858 1904 : if (innerrel_is_target)
1859 : {
1860 : Assert(fpinfo->jointype == JOIN_INNER);
1861 : Assert(fpinfo->joinclauses == NIL);
1862 0 : appendBinaryStringInfo(buf, join_sql_o.data, join_sql_o.len);
1863 : /* Pass EXISTS conditions to upper level */
1864 0 : if (additional_conds_o != NIL)
1865 : {
1866 : Assert(*additional_conds == NIL);
1867 0 : *additional_conds = additional_conds_o;
1868 : }
1869 16 : return;
1870 : }
1871 : }
1872 :
1873 : /* Deparse inner relation if not the target relation. */
1874 1920 : if (!innerrel_is_target)
1875 : {
1876 1920 : initStringInfo(&join_sql_i);
1877 1920 : deparseRangeTblRef(&join_sql_i, root, innerrel,
1878 1920 : fpinfo->make_innerrel_subquery,
1879 : ignore_rel, ignore_conds, &additional_conds_i,
1880 : params_list);
1881 :
1882 : /*
1883 : * SEMI-JOIN is deparsed as the EXISTS subquery. It references
1884 : * outer and inner relations, so it should be evaluated as the
1885 : * condition in the upper-level WHERE clause. We deparse the
1886 : * condition and pass it to upper level callers as an
1887 : * additional_conds list. Upper level callers are responsible for
1888 : * inserting conditions from the list where appropriate.
1889 : */
1890 1920 : if (fpinfo->jointype == JOIN_SEMI)
1891 : {
1892 : deparse_expr_cxt context;
1893 : StringInfoData str;
1894 :
1895 : /* Construct deparsed condition from this SEMI-JOIN */
1896 380 : initStringInfo(&str);
1897 380 : appendStringInfo(&str, "EXISTS (SELECT NULL FROM %s",
1898 : join_sql_i.data);
1899 :
1900 380 : context.buf = &str;
1901 380 : context.foreignrel = foreignrel;
1902 380 : context.scanrel = foreignrel;
1903 380 : context.root = root;
1904 380 : context.params_list = params_list;
1905 :
1906 : /*
1907 : * Append SEMI-JOIN clauses and EXISTS conditions from lower
1908 : * levels to the current EXISTS subquery
1909 : */
1910 380 : appendWhereClause(fpinfo->joinclauses, additional_conds_i, &context);
1911 :
1912 : /*
1913 : * EXISTS conditions, coming from lower join levels, have just
1914 : * been processed.
1915 : */
1916 380 : if (additional_conds_i != NIL)
1917 : {
1918 32 : list_free_deep(additional_conds_i);
1919 32 : additional_conds_i = NIL;
1920 : }
1921 :
1922 : /* Close parentheses for EXISTS subquery */
1923 380 : appendStringInfoChar(&str, ')');
1924 :
1925 380 : *additional_conds = lappend(*additional_conds, str.data);
1926 : }
1927 :
1928 : /*
1929 : * If outer relation is the target relation, skip deparsing it.
1930 : * See the above note about safety.
1931 : */
1932 1920 : if (outerrel_is_target)
1933 : {
1934 : Assert(fpinfo->jointype == JOIN_INNER);
1935 : Assert(fpinfo->joinclauses == NIL);
1936 16 : appendBinaryStringInfo(buf, join_sql_i.data, join_sql_i.len);
1937 : /* Pass EXISTS conditions to the upper call */
1938 16 : if (additional_conds_i != NIL)
1939 : {
1940 : Assert(*additional_conds == NIL);
1941 0 : *additional_conds = additional_conds_i;
1942 : }
1943 16 : return;
1944 : }
1945 : }
1946 :
1947 : /* Neither of the relations is the target relation. */
1948 : Assert(!outerrel_is_target && !innerrel_is_target);
1949 :
1950 : /*
1951 : * For semijoin FROM clause is deparsed as an outer relation. An inner
1952 : * relation and join clauses are converted to EXISTS condition and
1953 : * passed to the upper level.
1954 : */
1955 1904 : if (fpinfo->jointype == JOIN_SEMI)
1956 : {
1957 380 : appendBinaryStringInfo(buf, join_sql_o.data, join_sql_o.len);
1958 : }
1959 : else
1960 : {
1961 : /*
1962 : * For a join relation FROM clause, entry is deparsed as
1963 : *
1964 : * ((outer relation) <join type> (inner relation) ON
1965 : * (joinclauses))
1966 : */
1967 1524 : appendStringInfo(buf, "(%s %s JOIN %s ON ", join_sql_o.data,
1968 : get_jointype_name(fpinfo->jointype), join_sql_i.data);
1969 :
1970 : /* Append join clause; (TRUE) if no join clause */
1971 1524 : if (fpinfo->joinclauses)
1972 : {
1973 : deparse_expr_cxt context;
1974 :
1975 1480 : context.buf = buf;
1976 1480 : context.foreignrel = foreignrel;
1977 1480 : context.scanrel = foreignrel;
1978 1480 : context.root = root;
1979 1480 : context.params_list = params_list;
1980 :
1981 1480 : appendStringInfoChar(buf, '(');
1982 1480 : appendConditions(fpinfo->joinclauses, &context);
1983 1480 : appendStringInfoChar(buf, ')');
1984 : }
1985 : else
1986 44 : appendStringInfoString(buf, "(TRUE)");
1987 :
1988 : /* End the FROM clause entry. */
1989 1524 : appendStringInfoChar(buf, ')');
1990 : }
1991 :
1992 : /*
1993 : * Construct additional_conds to be passed to the upper caller from
1994 : * current level additional_conds and additional_conds, coming from
1995 : * inner and outer rels.
1996 : */
1997 1904 : if (additional_conds_o != NIL)
1998 : {
1999 96 : *additional_conds = list_concat(*additional_conds,
2000 : additional_conds_o);
2001 96 : list_free(additional_conds_o);
2002 : }
2003 :
2004 1904 : if (additional_conds_i != NIL)
2005 : {
2006 0 : *additional_conds = list_concat(*additional_conds,
2007 : additional_conds_i);
2008 0 : list_free(additional_conds_i);
2009 : }
2010 : }
2011 : else
2012 : {
2013 6456 : RangeTblEntry *rte = planner_rt_fetch(foreignrel->relid, root);
2014 :
2015 : /*
2016 : * Core code already has some lock on each rel being planned, so we
2017 : * can use NoLock here.
2018 : */
2019 6456 : Relation rel = table_open(rte->relid, NoLock);
2020 :
2021 6456 : deparseRelation(buf, rel);
2022 :
2023 : /*
2024 : * Add a unique alias to avoid any conflict in relation names due to
2025 : * pulled up subqueries in the query being built for a pushed down
2026 : * join.
2027 : */
2028 6456 : if (use_alias)
2029 3180 : appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, foreignrel->relid);
2030 :
2031 6456 : table_close(rel, NoLock);
2032 : }
2033 : }
2034 :
2035 : /*
2036 : * Append FROM clause entry for the given relation into buf.
2037 : * Conditions from lower-level SEMI-JOINs are appended to additional_conds
2038 : * and should be added to upper level WHERE clause.
2039 : */
2040 : static void
2041 3824 : deparseRangeTblRef(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
2042 : bool make_subquery, Index ignore_rel, List **ignore_conds,
2043 : List **additional_conds, List **params_list)
2044 : {
2045 3824 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
2046 :
2047 : /* Should only be called in these cases. */
2048 : Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
2049 :
2050 : Assert(fpinfo->local_conds == NIL);
2051 :
2052 : /* If make_subquery is true, deparse the relation as a subquery. */
2053 3824 : if (make_subquery)
2054 : {
2055 : List *retrieved_attrs;
2056 : int ncols;
2057 :
2058 : /*
2059 : * The given relation shouldn't contain the target relation, because
2060 : * this should only happen for input relations for a full join, and
2061 : * such relations can never contain an UPDATE/DELETE target.
2062 : */
2063 : Assert(ignore_rel == 0 ||
2064 : !bms_is_member(ignore_rel, foreignrel->relids));
2065 :
2066 : /* Deparse the subquery representing the relation. */
2067 100 : appendStringInfoChar(buf, '(');
2068 100 : deparseSelectStmtForRel(buf, root, foreignrel, NIL,
2069 : fpinfo->remote_conds, NIL,
2070 : false, false, true,
2071 : &retrieved_attrs, params_list);
2072 100 : appendStringInfoChar(buf, ')');
2073 :
2074 : /* Append the relation alias. */
2075 100 : appendStringInfo(buf, " %s%d", SUBQUERY_REL_ALIAS_PREFIX,
2076 : fpinfo->relation_index);
2077 :
2078 : /*
2079 : * Append the column aliases if needed. Note that the subquery emits
2080 : * expressions specified in the relation's reltarget (see
2081 : * deparseSubqueryTargetList).
2082 : */
2083 100 : ncols = list_length(foreignrel->reltarget->exprs);
2084 100 : if (ncols > 0)
2085 : {
2086 : int i;
2087 :
2088 92 : appendStringInfoChar(buf, '(');
2089 232 : for (i = 1; i <= ncols; i++)
2090 : {
2091 140 : if (i > 1)
2092 48 : appendStringInfoString(buf, ", ");
2093 :
2094 140 : appendStringInfo(buf, "%s%d", SUBQUERY_COL_ALIAS_PREFIX, i);
2095 : }
2096 92 : appendStringInfoChar(buf, ')');
2097 : }
2098 : }
2099 : else
2100 3724 : deparseFromExprForRel(buf, root, foreignrel, true, ignore_rel,
2101 : ignore_conds, additional_conds,
2102 : params_list);
2103 3824 : }
2104 :
2105 : /*
2106 : * deparse remote INSERT statement
2107 : *
2108 : * The statement text is appended to buf, and we also create an integer List
2109 : * of the columns being retrieved by WITH CHECK OPTION or RETURNING (if any),
2110 : * which is returned to *retrieved_attrs.
2111 : *
2112 : * This also stores end position of the VALUES clause, so that we can rebuild
2113 : * an INSERT for a batch of rows later.
2114 : */
2115 : void
2116 282 : deparseInsertSql(StringInfo buf, RangeTblEntry *rte,
2117 : Index rtindex, Relation rel,
2118 : List *targetAttrs, bool doNothing,
2119 : List *withCheckOptionList, List *returningList,
2120 : List **retrieved_attrs, int *values_end_len)
2121 : {
2122 282 : TupleDesc tupdesc = RelationGetDescr(rel);
2123 : AttrNumber pindex;
2124 : bool first;
2125 : ListCell *lc;
2126 :
2127 282 : appendStringInfoString(buf, "INSERT INTO ");
2128 282 : deparseRelation(buf, rel);
2129 :
2130 282 : if (targetAttrs)
2131 : {
2132 280 : appendStringInfoChar(buf, '(');
2133 :
2134 280 : first = true;
2135 1050 : foreach(lc, targetAttrs)
2136 : {
2137 770 : int attnum = lfirst_int(lc);
2138 :
2139 770 : if (!first)
2140 490 : appendStringInfoString(buf, ", ");
2141 770 : first = false;
2142 :
2143 770 : deparseColumnRef(buf, rtindex, attnum, rte, false);
2144 : }
2145 :
2146 280 : appendStringInfoString(buf, ") VALUES (");
2147 :
2148 280 : pindex = 1;
2149 280 : first = true;
2150 1050 : foreach(lc, targetAttrs)
2151 : {
2152 770 : int attnum = lfirst_int(lc);
2153 770 : Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
2154 :
2155 770 : if (!first)
2156 490 : appendStringInfoString(buf, ", ");
2157 770 : first = false;
2158 :
2159 770 : if (attr->attgenerated)
2160 20 : appendStringInfoString(buf, "DEFAULT");
2161 : else
2162 : {
2163 750 : appendStringInfo(buf, "$%d", pindex);
2164 750 : pindex++;
2165 : }
2166 : }
2167 :
2168 280 : appendStringInfoChar(buf, ')');
2169 : }
2170 : else
2171 2 : appendStringInfoString(buf, " DEFAULT VALUES");
2172 282 : *values_end_len = buf->len;
2173 :
2174 282 : if (doNothing)
2175 6 : appendStringInfoString(buf, " ON CONFLICT DO NOTHING");
2176 :
2177 282 : deparseReturningList(buf, rte, rtindex, rel,
2178 282 : rel->trigdesc && rel->trigdesc->trig_insert_after_row,
2179 : withCheckOptionList, returningList, retrieved_attrs);
2180 282 : }
2181 :
2182 : /*
2183 : * rebuild remote INSERT statement
2184 : *
2185 : * Provided a number of rows in a batch, builds INSERT statement with the
2186 : * right number of parameters.
2187 : */
2188 : void
2189 52 : rebuildInsertSql(StringInfo buf, Relation rel,
2190 : char *orig_query, List *target_attrs,
2191 : int values_end_len, int num_params,
2192 : int num_rows)
2193 : {
2194 52 : TupleDesc tupdesc = RelationGetDescr(rel);
2195 : int i;
2196 : int pindex;
2197 : bool first;
2198 : ListCell *lc;
2199 :
2200 : /* Make sure the values_end_len is sensible */
2201 : Assert((values_end_len > 0) && (values_end_len <= strlen(orig_query)));
2202 :
2203 : /* Copy up to the end of the first record from the original query */
2204 52 : appendBinaryStringInfo(buf, orig_query, values_end_len);
2205 :
2206 : /*
2207 : * Add records to VALUES clause (we already have parameters for the first
2208 : * row, so start at the right offset).
2209 : */
2210 52 : pindex = num_params + 1;
2211 206 : for (i = 0; i < num_rows; i++)
2212 : {
2213 154 : appendStringInfoString(buf, ", (");
2214 :
2215 154 : first = true;
2216 452 : foreach(lc, target_attrs)
2217 : {
2218 298 : int attnum = lfirst_int(lc);
2219 298 : Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
2220 :
2221 298 : if (!first)
2222 144 : appendStringInfoString(buf, ", ");
2223 298 : first = false;
2224 :
2225 298 : if (attr->attgenerated)
2226 4 : appendStringInfoString(buf, "DEFAULT");
2227 : else
2228 : {
2229 294 : appendStringInfo(buf, "$%d", pindex);
2230 294 : pindex++;
2231 : }
2232 : }
2233 :
2234 154 : appendStringInfoChar(buf, ')');
2235 : }
2236 :
2237 : /* Copy stuff after VALUES clause from the original query */
2238 52 : appendStringInfoString(buf, orig_query + values_end_len);
2239 52 : }
2240 :
2241 : /*
2242 : * deparse remote UPDATE statement
2243 : *
2244 : * The statement text is appended to buf, and we also create an integer List
2245 : * of the columns being retrieved by WITH CHECK OPTION or RETURNING (if any),
2246 : * which is returned to *retrieved_attrs.
2247 : */
2248 : void
2249 112 : deparseUpdateSql(StringInfo buf, RangeTblEntry *rte,
2250 : Index rtindex, Relation rel,
2251 : List *targetAttrs,
2252 : List *withCheckOptionList, List *returningList,
2253 : List **retrieved_attrs)
2254 : {
2255 112 : TupleDesc tupdesc = RelationGetDescr(rel);
2256 : AttrNumber pindex;
2257 : bool first;
2258 : ListCell *lc;
2259 :
2260 112 : appendStringInfoString(buf, "UPDATE ");
2261 112 : deparseRelation(buf, rel);
2262 112 : appendStringInfoString(buf, " SET ");
2263 :
2264 112 : pindex = 2; /* ctid is always the first param */
2265 112 : first = true;
2266 278 : foreach(lc, targetAttrs)
2267 : {
2268 166 : int attnum = lfirst_int(lc);
2269 166 : Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
2270 :
2271 166 : if (!first)
2272 54 : appendStringInfoString(buf, ", ");
2273 166 : first = false;
2274 :
2275 166 : deparseColumnRef(buf, rtindex, attnum, rte, false);
2276 166 : if (attr->attgenerated)
2277 8 : appendStringInfoString(buf, " = DEFAULT");
2278 : else
2279 : {
2280 158 : appendStringInfo(buf, " = $%d", pindex);
2281 158 : pindex++;
2282 : }
2283 : }
2284 112 : appendStringInfoString(buf, " WHERE ctid = $1");
2285 :
2286 112 : deparseReturningList(buf, rte, rtindex, rel,
2287 112 : rel->trigdesc && rel->trigdesc->trig_update_after_row,
2288 : withCheckOptionList, returningList, retrieved_attrs);
2289 112 : }
2290 :
2291 : /*
2292 : * deparse remote UPDATE statement
2293 : *
2294 : * 'buf' is the output buffer to append the statement to
2295 : * 'rtindex' is the RT index of the associated target relation
2296 : * 'rel' is the relation descriptor for the target relation
2297 : * 'foreignrel' is the RelOptInfo for the target relation or the join relation
2298 : * containing all base relations in the query
2299 : * 'targetlist' is the tlist of the underlying foreign-scan plan node
2300 : * (note that this only contains new-value expressions and junk attrs)
2301 : * 'targetAttrs' is the target columns of the UPDATE
2302 : * 'remote_conds' is the qual clauses that must be evaluated remotely
2303 : * '*params_list' is an output list of exprs that will become remote Params
2304 : * 'returningList' is the RETURNING targetlist
2305 : * '*retrieved_attrs' is an output list of integers of columns being retrieved
2306 : * by RETURNING (if any)
2307 : */
2308 : void
2309 90 : deparseDirectUpdateSql(StringInfo buf, PlannerInfo *root,
2310 : Index rtindex, Relation rel,
2311 : RelOptInfo *foreignrel,
2312 : List *targetlist,
2313 : List *targetAttrs,
2314 : List *remote_conds,
2315 : List **params_list,
2316 : List *returningList,
2317 : List **retrieved_attrs)
2318 : {
2319 : deparse_expr_cxt context;
2320 : int nestlevel;
2321 : bool first;
2322 90 : RangeTblEntry *rte = planner_rt_fetch(rtindex, root);
2323 : ListCell *lc,
2324 : *lc2;
2325 90 : List *additional_conds = NIL;
2326 :
2327 : /* Set up context struct for recursion */
2328 90 : context.root = root;
2329 90 : context.foreignrel = foreignrel;
2330 90 : context.scanrel = foreignrel;
2331 90 : context.buf = buf;
2332 90 : context.params_list = params_list;
2333 :
2334 90 : appendStringInfoString(buf, "UPDATE ");
2335 90 : deparseRelation(buf, rel);
2336 90 : if (foreignrel->reloptkind == RELOPT_JOINREL)
2337 8 : appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, rtindex);
2338 90 : appendStringInfoString(buf, " SET ");
2339 :
2340 : /* Make sure any constants in the exprs are printed portably */
2341 90 : nestlevel = set_transmission_modes();
2342 :
2343 90 : first = true;
2344 196 : forboth(lc, targetlist, lc2, targetAttrs)
2345 : {
2346 106 : TargetEntry *tle = lfirst_node(TargetEntry, lc);
2347 106 : int attnum = lfirst_int(lc2);
2348 :
2349 : /* update's new-value expressions shouldn't be resjunk */
2350 : Assert(!tle->resjunk);
2351 :
2352 106 : if (!first)
2353 16 : appendStringInfoString(buf, ", ");
2354 106 : first = false;
2355 :
2356 106 : deparseColumnRef(buf, rtindex, attnum, rte, false);
2357 106 : appendStringInfoString(buf, " = ");
2358 106 : deparseExpr((Expr *) tle->expr, &context);
2359 : }
2360 :
2361 90 : reset_transmission_modes(nestlevel);
2362 :
2363 90 : if (foreignrel->reloptkind == RELOPT_JOINREL)
2364 : {
2365 8 : List *ignore_conds = NIL;
2366 :
2367 :
2368 8 : appendStringInfoString(buf, " FROM ");
2369 8 : deparseFromExprForRel(buf, root, foreignrel, true, rtindex,
2370 : &ignore_conds, &additional_conds, params_list);
2371 8 : remote_conds = list_concat(remote_conds, ignore_conds);
2372 : }
2373 :
2374 90 : appendWhereClause(remote_conds, additional_conds, &context);
2375 :
2376 90 : if (additional_conds != NIL)
2377 0 : list_free_deep(additional_conds);
2378 :
2379 90 : if (foreignrel->reloptkind == RELOPT_JOINREL)
2380 8 : deparseExplicitTargetList(returningList, true, retrieved_attrs,
2381 : &context);
2382 : else
2383 82 : deparseReturningList(buf, rte, rtindex, rel, false,
2384 : NIL, returningList, retrieved_attrs);
2385 90 : }
2386 :
2387 : /*
2388 : * deparse remote DELETE statement
2389 : *
2390 : * The statement text is appended to buf, and we also create an integer List
2391 : * of the columns being retrieved by RETURNING (if any), which is returned
2392 : * to *retrieved_attrs.
2393 : */
2394 : void
2395 36 : deparseDeleteSql(StringInfo buf, RangeTblEntry *rte,
2396 : Index rtindex, Relation rel,
2397 : List *returningList,
2398 : List **retrieved_attrs)
2399 : {
2400 36 : appendStringInfoString(buf, "DELETE FROM ");
2401 36 : deparseRelation(buf, rel);
2402 36 : appendStringInfoString(buf, " WHERE ctid = $1");
2403 :
2404 36 : deparseReturningList(buf, rte, rtindex, rel,
2405 36 : rel->trigdesc && rel->trigdesc->trig_delete_after_row,
2406 : NIL, returningList, retrieved_attrs);
2407 36 : }
2408 :
2409 : /*
2410 : * deparse remote DELETE statement
2411 : *
2412 : * 'buf' is the output buffer to append the statement to
2413 : * 'rtindex' is the RT index of the associated target relation
2414 : * 'rel' is the relation descriptor for the target relation
2415 : * 'foreignrel' is the RelOptInfo for the target relation or the join relation
2416 : * containing all base relations in the query
2417 : * 'remote_conds' is the qual clauses that must be evaluated remotely
2418 : * '*params_list' is an output list of exprs that will become remote Params
2419 : * 'returningList' is the RETURNING targetlist
2420 : * '*retrieved_attrs' is an output list of integers of columns being retrieved
2421 : * by RETURNING (if any)
2422 : */
2423 : void
2424 118 : deparseDirectDeleteSql(StringInfo buf, PlannerInfo *root,
2425 : Index rtindex, Relation rel,
2426 : RelOptInfo *foreignrel,
2427 : List *remote_conds,
2428 : List **params_list,
2429 : List *returningList,
2430 : List **retrieved_attrs)
2431 : {
2432 : deparse_expr_cxt context;
2433 118 : List *additional_conds = NIL;
2434 :
2435 : /* Set up context struct for recursion */
2436 118 : context.root = root;
2437 118 : context.foreignrel = foreignrel;
2438 118 : context.scanrel = foreignrel;
2439 118 : context.buf = buf;
2440 118 : context.params_list = params_list;
2441 :
2442 118 : appendStringInfoString(buf, "DELETE FROM ");
2443 118 : deparseRelation(buf, rel);
2444 118 : if (foreignrel->reloptkind == RELOPT_JOINREL)
2445 8 : appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, rtindex);
2446 :
2447 118 : if (foreignrel->reloptkind == RELOPT_JOINREL)
2448 : {
2449 8 : List *ignore_conds = NIL;
2450 :
2451 8 : appendStringInfoString(buf, " USING ");
2452 8 : deparseFromExprForRel(buf, root, foreignrel, true, rtindex,
2453 : &ignore_conds, &additional_conds, params_list);
2454 8 : remote_conds = list_concat(remote_conds, ignore_conds);
2455 : }
2456 :
2457 118 : appendWhereClause(remote_conds, additional_conds, &context);
2458 :
2459 118 : if (additional_conds != NIL)
2460 0 : list_free_deep(additional_conds);
2461 :
2462 118 : if (foreignrel->reloptkind == RELOPT_JOINREL)
2463 8 : deparseExplicitTargetList(returningList, true, retrieved_attrs,
2464 : &context);
2465 : else
2466 110 : deparseReturningList(buf, planner_rt_fetch(rtindex, root),
2467 : rtindex, rel, false,
2468 : NIL, returningList, retrieved_attrs);
2469 118 : }
2470 :
2471 : /*
2472 : * Add a RETURNING clause, if needed, to an INSERT/UPDATE/DELETE.
2473 : */
2474 : static void
2475 622 : deparseReturningList(StringInfo buf, RangeTblEntry *rte,
2476 : Index rtindex, Relation rel,
2477 : bool trig_after_row,
2478 : List *withCheckOptionList,
2479 : List *returningList,
2480 : List **retrieved_attrs)
2481 : {
2482 622 : Bitmapset *attrs_used = NULL;
2483 :
2484 622 : if (trig_after_row)
2485 : {
2486 : /* whole-row reference acquires all non-system columns */
2487 48 : attrs_used =
2488 48 : bms_make_singleton(0 - FirstLowInvalidHeapAttributeNumber);
2489 : }
2490 :
2491 622 : if (withCheckOptionList != NIL)
2492 : {
2493 : /*
2494 : * We need the attrs, non-system and system, mentioned in the local
2495 : * query's WITH CHECK OPTION list.
2496 : *
2497 : * Note: we do this to ensure that WCO constraints will be evaluated
2498 : * on the data actually inserted/updated on the remote side, which
2499 : * might differ from the data supplied by the core code, for example
2500 : * as a result of remote triggers.
2501 : */
2502 38 : pull_varattnos((Node *) withCheckOptionList, rtindex,
2503 : &attrs_used);
2504 : }
2505 :
2506 622 : if (returningList != NIL)
2507 : {
2508 : /*
2509 : * We need the attrs, non-system and system, mentioned in the local
2510 : * query's RETURNING list.
2511 : */
2512 152 : pull_varattnos((Node *) returningList, rtindex,
2513 : &attrs_used);
2514 : }
2515 :
2516 622 : if (attrs_used != NULL)
2517 236 : deparseTargetList(buf, rte, rtindex, rel, true, attrs_used, false,
2518 : retrieved_attrs);
2519 : else
2520 386 : *retrieved_attrs = NIL;
2521 622 : }
2522 :
2523 : /*
2524 : * Construct SELECT statement to acquire size in blocks of given relation.
2525 : *
2526 : * Note: we use local definition of block size, not remote definition.
2527 : * This is perhaps debatable.
2528 : *
2529 : * Note: pg_relation_size() exists in 8.1 and later.
2530 : */
2531 : void
2532 84 : deparseAnalyzeSizeSql(StringInfo buf, Relation rel)
2533 : {
2534 : StringInfoData relname;
2535 :
2536 : /* We'll need the remote relation name as a literal. */
2537 84 : initStringInfo(&relname);
2538 84 : deparseRelation(&relname, rel);
2539 :
2540 84 : appendStringInfoString(buf, "SELECT pg_catalog.pg_relation_size(");
2541 84 : deparseStringLiteral(buf, relname.data);
2542 84 : appendStringInfo(buf, "::pg_catalog.regclass) / %d", BLCKSZ);
2543 84 : }
2544 :
2545 : /*
2546 : * Construct SELECT statement to acquire the number of rows and the relkind of
2547 : * a relation.
2548 : *
2549 : * Note: we just return the remote server's reltuples value, which might
2550 : * be off a good deal, but it doesn't seem worth working harder. See
2551 : * comments in postgresAcquireSampleRowsFunc.
2552 : */
2553 : void
2554 84 : deparseAnalyzeInfoSql(StringInfo buf, Relation rel)
2555 : {
2556 : StringInfoData relname;
2557 :
2558 : /* We'll need the remote relation name as a literal. */
2559 84 : initStringInfo(&relname);
2560 84 : deparseRelation(&relname, rel);
2561 :
2562 84 : appendStringInfoString(buf, "SELECT reltuples, relkind FROM pg_catalog.pg_class WHERE oid = ");
2563 84 : deparseStringLiteral(buf, relname.data);
2564 84 : appendStringInfoString(buf, "::pg_catalog.regclass");
2565 84 : }
2566 :
2567 : /*
2568 : * Construct SELECT statement to acquire sample rows of given relation.
2569 : *
2570 : * SELECT command is appended to buf, and list of columns retrieved
2571 : * is returned to *retrieved_attrs.
2572 : *
2573 : * We only support sampling methods we can decide based on server version.
2574 : * Allowing custom TSM modules (like tsm_system_rows) might be useful, but it
2575 : * would require detecting which extensions are installed, to allow automatic
2576 : * fall-back. Moreover, the methods may use different parameters like number
2577 : * of rows (and not sampling rate). So we leave this for future improvements.
2578 : *
2579 : * Using random() to sample rows on the remote server has the advantage that
2580 : * this works on all PostgreSQL versions (unlike TABLESAMPLE), and that it
2581 : * does the sampling on the remote side (without transferring everything and
2582 : * then discarding most rows).
2583 : *
2584 : * The disadvantage is that we still have to read all rows and evaluate the
2585 : * random(), while TABLESAMPLE (at least with the "system" method) may skip.
2586 : * It's not that different from the "bernoulli" method, though.
2587 : *
2588 : * We could also do "ORDER BY random() LIMIT x", which would always pick
2589 : * the expected number of rows, but it requires sorting so it may be much
2590 : * more expensive (particularly on large tables, which is what the
2591 : * remote sampling is meant to improve).
2592 : */
2593 : void
2594 84 : deparseAnalyzeSql(StringInfo buf, Relation rel,
2595 : PgFdwSamplingMethod sample_method, double sample_frac,
2596 : List **retrieved_attrs)
2597 : {
2598 84 : Oid relid = RelationGetRelid(rel);
2599 84 : TupleDesc tupdesc = RelationGetDescr(rel);
2600 : int i;
2601 : char *colname;
2602 : List *options;
2603 : ListCell *lc;
2604 84 : bool first = true;
2605 :
2606 84 : *retrieved_attrs = NIL;
2607 :
2608 84 : appendStringInfoString(buf, "SELECT ");
2609 364 : for (i = 0; i < tupdesc->natts; i++)
2610 : {
2611 : /* Ignore dropped columns. */
2612 280 : if (TupleDescAttr(tupdesc, i)->attisdropped)
2613 6 : continue;
2614 :
2615 274 : if (!first)
2616 190 : appendStringInfoString(buf, ", ");
2617 274 : first = false;
2618 :
2619 : /* Use attribute name or column_name option. */
2620 274 : colname = NameStr(TupleDescAttr(tupdesc, i)->attname);
2621 274 : options = GetForeignColumnOptions(relid, i + 1);
2622 :
2623 274 : foreach(lc, options)
2624 : {
2625 6 : DefElem *def = (DefElem *) lfirst(lc);
2626 :
2627 6 : if (strcmp(def->defname, "column_name") == 0)
2628 : {
2629 6 : colname = defGetString(def);
2630 6 : break;
2631 : }
2632 : }
2633 :
2634 274 : appendStringInfoString(buf, quote_identifier(colname));
2635 :
2636 274 : *retrieved_attrs = lappend_int(*retrieved_attrs, i + 1);
2637 : }
2638 :
2639 : /* Don't generate bad syntax for zero-column relation. */
2640 84 : if (first)
2641 0 : appendStringInfoString(buf, "NULL");
2642 :
2643 : /*
2644 : * Construct FROM clause, and perhaps WHERE clause too, depending on the
2645 : * selected sampling method.
2646 : */
2647 84 : appendStringInfoString(buf, " FROM ");
2648 84 : deparseRelation(buf, rel);
2649 :
2650 84 : switch (sample_method)
2651 : {
2652 84 : case ANALYZE_SAMPLE_OFF:
2653 : /* nothing to do here */
2654 84 : break;
2655 :
2656 0 : case ANALYZE_SAMPLE_RANDOM:
2657 0 : appendStringInfo(buf, " WHERE pg_catalog.random() < %f", sample_frac);
2658 0 : break;
2659 :
2660 0 : case ANALYZE_SAMPLE_SYSTEM:
2661 0 : appendStringInfo(buf, " TABLESAMPLE SYSTEM(%f)", (100.0 * sample_frac));
2662 0 : break;
2663 :
2664 0 : case ANALYZE_SAMPLE_BERNOULLI:
2665 0 : appendStringInfo(buf, " TABLESAMPLE BERNOULLI(%f)", (100.0 * sample_frac));
2666 0 : break;
2667 :
2668 0 : case ANALYZE_SAMPLE_AUTO:
2669 : /* should have been resolved into actual method */
2670 0 : elog(ERROR, "unexpected sampling method");
2671 : break;
2672 : }
2673 84 : }
2674 :
2675 : /*
2676 : * Construct a simple "TRUNCATE rel" statement
2677 : */
2678 : void
2679 24 : deparseTruncateSql(StringInfo buf,
2680 : List *rels,
2681 : DropBehavior behavior,
2682 : bool restart_seqs)
2683 : {
2684 : ListCell *cell;
2685 :
2686 24 : appendStringInfoString(buf, "TRUNCATE ");
2687 :
2688 52 : foreach(cell, rels)
2689 : {
2690 28 : Relation rel = lfirst(cell);
2691 :
2692 28 : if (cell != list_head(rels))
2693 4 : appendStringInfoString(buf, ", ");
2694 :
2695 28 : deparseRelation(buf, rel);
2696 : }
2697 :
2698 24 : appendStringInfo(buf, " %s IDENTITY",
2699 : restart_seqs ? "RESTART" : "CONTINUE");
2700 :
2701 24 : if (behavior == DROP_RESTRICT)
2702 20 : appendStringInfoString(buf, " RESTRICT");
2703 4 : else if (behavior == DROP_CASCADE)
2704 4 : appendStringInfoString(buf, " CASCADE");
2705 24 : }
2706 :
2707 : /*
2708 : * Construct name to use for given column, and emit it into buf.
2709 : * If it has a column_name FDW option, use that instead of attribute name.
2710 : *
2711 : * If qualify_col is true, qualify column name with the alias of relation.
2712 : */
2713 : static void
2714 30554 : deparseColumnRef(StringInfo buf, int varno, int varattno, RangeTblEntry *rte,
2715 : bool qualify_col)
2716 : {
2717 : /* We support fetching the remote side's CTID and OID. */
2718 30554 : if (varattno == SelfItemPointerAttributeNumber)
2719 : {
2720 120 : if (qualify_col)
2721 116 : ADD_REL_QUALIFIER(buf, varno);
2722 120 : appendStringInfoString(buf, "ctid");
2723 : }
2724 30434 : else if (varattno < 0)
2725 : {
2726 : /*
2727 : * All other system attributes are fetched as 0, except for table OID,
2728 : * which is fetched as the local table OID. However, we must be
2729 : * careful; the table could be beneath an outer join, in which case it
2730 : * must go to NULL whenever the rest of the row does.
2731 : */
2732 0 : Oid fetchval = 0;
2733 :
2734 0 : if (varattno == TableOidAttributeNumber)
2735 0 : fetchval = rte->relid;
2736 :
2737 0 : if (qualify_col)
2738 : {
2739 0 : appendStringInfoString(buf, "CASE WHEN (");
2740 0 : ADD_REL_QUALIFIER(buf, varno);
2741 0 : appendStringInfo(buf, "*)::text IS NOT NULL THEN %u END", fetchval);
2742 : }
2743 : else
2744 0 : appendStringInfo(buf, "%u", fetchval);
2745 : }
2746 30434 : else if (varattno == 0)
2747 : {
2748 : /* Whole row reference */
2749 : Relation rel;
2750 : Bitmapset *attrs_used;
2751 :
2752 : /* Required only to be passed down to deparseTargetList(). */
2753 : List *retrieved_attrs;
2754 :
2755 : /*
2756 : * The lock on the relation will be held by upper callers, so it's
2757 : * fine to open it with no lock here.
2758 : */
2759 532 : rel = table_open(rte->relid, NoLock);
2760 :
2761 : /*
2762 : * The local name of the foreign table can not be recognized by the
2763 : * foreign server and the table it references on foreign server might
2764 : * have different column ordering or different columns than those
2765 : * declared locally. Hence we have to deparse whole-row reference as
2766 : * ROW(columns referenced locally). Construct this by deparsing a
2767 : * "whole row" attribute.
2768 : */
2769 532 : attrs_used = bms_add_member(NULL,
2770 : 0 - FirstLowInvalidHeapAttributeNumber);
2771 :
2772 : /*
2773 : * In case the whole-row reference is under an outer join then it has
2774 : * to go NULL whenever the rest of the row goes NULL. Deparsing a join
2775 : * query would always involve multiple relations, thus qualify_col
2776 : * would be true.
2777 : */
2778 532 : if (qualify_col)
2779 : {
2780 524 : appendStringInfoString(buf, "CASE WHEN (");
2781 524 : ADD_REL_QUALIFIER(buf, varno);
2782 524 : appendStringInfoString(buf, "*)::text IS NOT NULL THEN ");
2783 : }
2784 :
2785 532 : appendStringInfoString(buf, "ROW(");
2786 532 : deparseTargetList(buf, rte, varno, rel, false, attrs_used, qualify_col,
2787 : &retrieved_attrs);
2788 532 : appendStringInfoChar(buf, ')');
2789 :
2790 : /* Complete the CASE WHEN statement started above. */
2791 532 : if (qualify_col)
2792 524 : appendStringInfoString(buf, " END");
2793 :
2794 532 : table_close(rel, NoLock);
2795 532 : bms_free(attrs_used);
2796 : }
2797 : else
2798 : {
2799 29902 : char *colname = NULL;
2800 : List *options;
2801 : ListCell *lc;
2802 :
2803 : /* varno must not be any of OUTER_VAR, INNER_VAR and INDEX_VAR. */
2804 : Assert(!IS_SPECIAL_VARNO(varno));
2805 :
2806 : /*
2807 : * If it's a column of a foreign table, and it has the column_name FDW
2808 : * option, use that value.
2809 : */
2810 29902 : options = GetForeignColumnOptions(rte->relid, varattno);
2811 29902 : foreach(lc, options)
2812 : {
2813 6934 : DefElem *def = (DefElem *) lfirst(lc);
2814 :
2815 6934 : if (strcmp(def->defname, "column_name") == 0)
2816 : {
2817 6934 : colname = defGetString(def);
2818 6934 : break;
2819 : }
2820 : }
2821 :
2822 : /*
2823 : * If it's a column of a regular table or it doesn't have column_name
2824 : * FDW option, use attribute name.
2825 : */
2826 29902 : if (colname == NULL)
2827 22968 : colname = get_attname(rte->relid, varattno, false);
2828 :
2829 29902 : if (qualify_col)
2830 15448 : ADD_REL_QUALIFIER(buf, varno);
2831 :
2832 29902 : appendStringInfoString(buf, quote_identifier(colname));
2833 : }
2834 30554 : }
2835 :
2836 : /*
2837 : * Append remote name of specified foreign table to buf.
2838 : * Use value of table_name FDW option (if any) instead of relation's name.
2839 : * Similarly, schema_name FDW option overrides schema name.
2840 : */
2841 : static void
2842 7374 : deparseRelation(StringInfo buf, Relation rel)
2843 : {
2844 : ForeignTable *table;
2845 7374 : const char *nspname = NULL;
2846 7374 : const char *relname = NULL;
2847 : ListCell *lc;
2848 :
2849 : /* obtain additional catalog information. */
2850 7374 : table = GetForeignTable(RelationGetRelid(rel));
2851 :
2852 : /*
2853 : * Use value of FDW options if any, instead of the name of object itself.
2854 : */
2855 24260 : foreach(lc, table->options)
2856 : {
2857 16886 : DefElem *def = (DefElem *) lfirst(lc);
2858 :
2859 16886 : if (strcmp(def->defname, "schema_name") == 0)
2860 5154 : nspname = defGetString(def);
2861 11732 : else if (strcmp(def->defname, "table_name") == 0)
2862 7374 : relname = defGetString(def);
2863 : }
2864 :
2865 : /*
2866 : * Note: we could skip printing the schema name if it's pg_catalog, but
2867 : * that doesn't seem worth the trouble.
2868 : */
2869 7374 : if (nspname == NULL)
2870 2220 : nspname = get_namespace_name(RelationGetNamespace(rel));
2871 7374 : if (relname == NULL)
2872 0 : relname = RelationGetRelationName(rel);
2873 :
2874 7374 : appendStringInfo(buf, "%s.%s",
2875 : quote_identifier(nspname), quote_identifier(relname));
2876 7374 : }
2877 :
2878 : /*
2879 : * Append a SQL string literal representing "val" to buf.
2880 : */
2881 : void
2882 680 : deparseStringLiteral(StringInfo buf, const char *val)
2883 : {
2884 : const char *valptr;
2885 :
2886 : /*
2887 : * Rather than making assumptions about the remote server's value of
2888 : * standard_conforming_strings, always use E'foo' syntax if there are any
2889 : * backslashes. This will fail on remote servers before 8.1, but those
2890 : * are long out of support.
2891 : */
2892 680 : if (strchr(val, '\\') != NULL)
2893 2 : appendStringInfoChar(buf, ESCAPE_STRING_SYNTAX);
2894 680 : appendStringInfoChar(buf, '\'');
2895 6104 : for (valptr = val; *valptr; valptr++)
2896 : {
2897 5424 : char ch = *valptr;
2898 :
2899 5424 : if (SQL_STR_DOUBLE(ch, true))
2900 4 : appendStringInfoChar(buf, ch);
2901 5424 : appendStringInfoChar(buf, ch);
2902 : }
2903 680 : appendStringInfoChar(buf, '\'');
2904 680 : }
2905 :
2906 : /*
2907 : * Deparse given expression into context->buf.
2908 : *
2909 : * This function must support all the same node types that foreign_expr_walker
2910 : * accepts.
2911 : *
2912 : * Note: unlike ruleutils.c, we just use a simple hard-wired parenthesization
2913 : * scheme: anything more complex than a Var, Const, function call or cast
2914 : * should be self-parenthesized.
2915 : */
2916 : static void
2917 24922 : deparseExpr(Expr *node, deparse_expr_cxt *context)
2918 : {
2919 24922 : if (node == NULL)
2920 0 : return;
2921 :
2922 24922 : switch (nodeTag(node))
2923 : {
2924 17216 : case T_Var:
2925 17216 : deparseVar((Var *) node, context);
2926 17216 : break;
2927 1170 : case T_Const:
2928 1170 : deparseConst((Const *) node, context, 0);
2929 1170 : break;
2930 62 : case T_Param:
2931 62 : deparseParam((Param *) node, context);
2932 62 : break;
2933 2 : case T_SubscriptingRef:
2934 2 : deparseSubscriptingRef((SubscriptingRef *) node, context);
2935 2 : break;
2936 116 : case T_FuncExpr:
2937 116 : deparseFuncExpr((FuncExpr *) node, context);
2938 116 : break;
2939 5554 : case T_OpExpr:
2940 5554 : deparseOpExpr((OpExpr *) node, context);
2941 5554 : break;
2942 2 : case T_DistinctExpr:
2943 2 : deparseDistinctExpr((DistinctExpr *) node, context);
2944 2 : break;
2945 14 : case T_ScalarArrayOpExpr:
2946 14 : deparseScalarArrayOpExpr((ScalarArrayOpExpr *) node, context);
2947 14 : break;
2948 72 : case T_RelabelType:
2949 72 : deparseRelabelType((RelabelType *) node, context);
2950 72 : break;
2951 6 : case T_ArrayCoerceExpr:
2952 6 : deparseArrayCoerceExpr((ArrayCoerceExpr *) node, context);
2953 6 : break;
2954 76 : case T_BoolExpr:
2955 76 : deparseBoolExpr((BoolExpr *) node, context);
2956 76 : break;
2957 56 : case T_NullTest:
2958 56 : deparseNullTest((NullTest *) node, context);
2959 56 : break;
2960 42 : case T_CaseExpr:
2961 42 : deparseCaseExpr((CaseExpr *) node, context);
2962 42 : break;
2963 8 : case T_ArrayExpr:
2964 8 : deparseArrayExpr((ArrayExpr *) node, context);
2965 8 : break;
2966 526 : case T_Aggref:
2967 526 : deparseAggref((Aggref *) node, context);
2968 526 : break;
2969 0 : default:
2970 0 : elog(ERROR, "unsupported expression type for deparse: %d",
2971 : (int) nodeTag(node));
2972 : break;
2973 : }
2974 : }
2975 :
2976 : /*
2977 : * Deparse given Var node into context->buf.
2978 : *
2979 : * If the Var belongs to the foreign relation, just print its remote name.
2980 : * Otherwise, it's effectively a Param (and will in fact be a Param at
2981 : * run time). Handle it the same way we handle plain Params --- see
2982 : * deparseParam for comments.
2983 : */
2984 : static void
2985 17216 : deparseVar(Var *node, deparse_expr_cxt *context)
2986 : {
2987 17216 : Relids relids = context->scanrel->relids;
2988 : int relno;
2989 : int colno;
2990 :
2991 : /* Qualify columns when multiple relations are involved. */
2992 17216 : bool qualify_col = (bms_membership(relids) == BMS_MULTIPLE);
2993 :
2994 : /*
2995 : * If the Var belongs to the foreign relation that is deparsed as a
2996 : * subquery, use the relation and column alias to the Var provided by the
2997 : * subquery, instead of the remote name.
2998 : */
2999 17216 : if (is_subquery_var(node, context->scanrel, &relno, &colno))
3000 : {
3001 304 : appendStringInfo(context->buf, "%s%d.%s%d",
3002 : SUBQUERY_REL_ALIAS_PREFIX, relno,
3003 : SUBQUERY_COL_ALIAS_PREFIX, colno);
3004 304 : return;
3005 : }
3006 :
3007 16912 : if (bms_is_member(node->varno, relids) && node->varlevelsup == 0)
3008 16482 : deparseColumnRef(context->buf, node->varno, node->varattno,
3009 16482 : planner_rt_fetch(node->varno, context->root),
3010 : qualify_col);
3011 : else
3012 : {
3013 : /* Treat like a Param */
3014 430 : if (context->params_list)
3015 : {
3016 22 : int pindex = 0;
3017 : ListCell *lc;
3018 :
3019 : /* find its index in params_list */
3020 22 : foreach(lc, *context->params_list)
3021 : {
3022 0 : pindex++;
3023 0 : if (equal(node, (Node *) lfirst(lc)))
3024 0 : break;
3025 : }
3026 22 : if (lc == NULL)
3027 : {
3028 : /* not in list, so add it */
3029 22 : pindex++;
3030 22 : *context->params_list = lappend(*context->params_list, node);
3031 : }
3032 :
3033 22 : printRemoteParam(pindex, node->vartype, node->vartypmod, context);
3034 : }
3035 : else
3036 : {
3037 408 : printRemotePlaceholder(node->vartype, node->vartypmod, context);
3038 : }
3039 : }
3040 : }
3041 :
3042 : /*
3043 : * Deparse given constant value into context->buf.
3044 : *
3045 : * This function has to be kept in sync with ruleutils.c's get_const_expr.
3046 : *
3047 : * As in that function, showtype can be -1 to never show "::typename"
3048 : * decoration, +1 to always show it, or 0 to show it only if the constant
3049 : * wouldn't be assumed to be the right type by default.
3050 : *
3051 : * In addition, this code allows showtype to be -2 to indicate that we should
3052 : * not show "::typename" decoration if the constant is printed as an untyped
3053 : * literal or NULL (while in other cases, behaving as for showtype == 0).
3054 : */
3055 : static void
3056 3746 : deparseConst(Const *node, deparse_expr_cxt *context, int showtype)
3057 : {
3058 3746 : StringInfo buf = context->buf;
3059 : Oid typoutput;
3060 : bool typIsVarlena;
3061 : char *extval;
3062 3746 : bool isfloat = false;
3063 3746 : bool isstring = false;
3064 : bool needlabel;
3065 :
3066 3746 : if (node->constisnull)
3067 : {
3068 38 : appendStringInfoString(buf, "NULL");
3069 38 : if (showtype >= 0)
3070 38 : appendStringInfo(buf, "::%s",
3071 : deparse_type_name(node->consttype,
3072 : node->consttypmod));
3073 38 : return;
3074 : }
3075 :
3076 3708 : getTypeOutputInfo(node->consttype,
3077 : &typoutput, &typIsVarlena);
3078 3708 : extval = OidOutputFunctionCall(typoutput, node->constvalue);
3079 :
3080 3708 : switch (node->consttype)
3081 : {
3082 3542 : case INT2OID:
3083 : case INT4OID:
3084 : case INT8OID:
3085 : case OIDOID:
3086 : case FLOAT4OID:
3087 : case FLOAT8OID:
3088 : case NUMERICOID:
3089 : {
3090 : /*
3091 : * No need to quote unless it's a special value such as 'NaN'.
3092 : * See comments in get_const_expr().
3093 : */
3094 3542 : if (strspn(extval, "0123456789+-eE.") == strlen(extval))
3095 : {
3096 3542 : if (extval[0] == '+' || extval[0] == '-')
3097 2 : appendStringInfo(buf, "(%s)", extval);
3098 : else
3099 3540 : appendStringInfoString(buf, extval);
3100 3542 : if (strcspn(extval, "eE.") != strlen(extval))
3101 4 : isfloat = true; /* it looks like a float */
3102 : }
3103 : else
3104 0 : appendStringInfo(buf, "'%s'", extval);
3105 : }
3106 3542 : break;
3107 0 : case BITOID:
3108 : case VARBITOID:
3109 0 : appendStringInfo(buf, "B'%s'", extval);
3110 0 : break;
3111 4 : case BOOLOID:
3112 4 : if (strcmp(extval, "t") == 0)
3113 4 : appendStringInfoString(buf, "true");
3114 : else
3115 0 : appendStringInfoString(buf, "false");
3116 4 : break;
3117 162 : default:
3118 162 : deparseStringLiteral(buf, extval);
3119 162 : isstring = true;
3120 162 : break;
3121 : }
3122 :
3123 3708 : pfree(extval);
3124 :
3125 3708 : if (showtype == -1)
3126 0 : return; /* never print type label */
3127 :
3128 : /*
3129 : * For showtype == 0, append ::typename unless the constant will be
3130 : * implicitly typed as the right type when it is read in.
3131 : *
3132 : * XXX this code has to be kept in sync with the behavior of the parser,
3133 : * especially make_const.
3134 : */
3135 3708 : switch (node->consttype)
3136 : {
3137 3058 : case BOOLOID:
3138 : case INT4OID:
3139 : case UNKNOWNOID:
3140 3058 : needlabel = false;
3141 3058 : break;
3142 42 : case NUMERICOID:
3143 42 : needlabel = !isfloat || (node->consttypmod >= 0);
3144 42 : break;
3145 608 : default:
3146 608 : if (showtype == -2)
3147 : {
3148 : /* label unless we printed it as an untyped string */
3149 86 : needlabel = !isstring;
3150 : }
3151 : else
3152 522 : needlabel = true;
3153 608 : break;
3154 : }
3155 3708 : if (needlabel || showtype > 0)
3156 560 : appendStringInfo(buf, "::%s",
3157 : deparse_type_name(node->consttype,
3158 : node->consttypmod));
3159 : }
3160 :
3161 : /*
3162 : * Deparse given Param node.
3163 : *
3164 : * If we're generating the query "for real", add the Param to
3165 : * context->params_list if it's not already present, and then use its index
3166 : * in that list as the remote parameter number. During EXPLAIN, there's
3167 : * no need to identify a parameter number.
3168 : */
3169 : static void
3170 62 : deparseParam(Param *node, deparse_expr_cxt *context)
3171 : {
3172 62 : if (context->params_list)
3173 : {
3174 38 : int pindex = 0;
3175 : ListCell *lc;
3176 :
3177 : /* find its index in params_list */
3178 42 : foreach(lc, *context->params_list)
3179 : {
3180 4 : pindex++;
3181 4 : if (equal(node, (Node *) lfirst(lc)))
3182 0 : break;
3183 : }
3184 38 : if (lc == NULL)
3185 : {
3186 : /* not in list, so add it */
3187 38 : pindex++;
3188 38 : *context->params_list = lappend(*context->params_list, node);
3189 : }
3190 :
3191 38 : printRemoteParam(pindex, node->paramtype, node->paramtypmod, context);
3192 : }
3193 : else
3194 : {
3195 24 : printRemotePlaceholder(node->paramtype, node->paramtypmod, context);
3196 : }
3197 62 : }
3198 :
3199 : /*
3200 : * Deparse a container subscript expression.
3201 : */
3202 : static void
3203 2 : deparseSubscriptingRef(SubscriptingRef *node, deparse_expr_cxt *context)
3204 : {
3205 2 : StringInfo buf = context->buf;
3206 : ListCell *lowlist_item;
3207 : ListCell *uplist_item;
3208 :
3209 : /* Always parenthesize the expression. */
3210 2 : appendStringInfoChar(buf, '(');
3211 :
3212 : /*
3213 : * Deparse referenced array expression first. If that expression includes
3214 : * a cast, we have to parenthesize to prevent the array subscript from
3215 : * being taken as typename decoration. We can avoid that in the typical
3216 : * case of subscripting a Var, but otherwise do it.
3217 : */
3218 2 : if (IsA(node->refexpr, Var))
3219 0 : deparseExpr(node->refexpr, context);
3220 : else
3221 : {
3222 2 : appendStringInfoChar(buf, '(');
3223 2 : deparseExpr(node->refexpr, context);
3224 2 : appendStringInfoChar(buf, ')');
3225 : }
3226 :
3227 : /* Deparse subscript expressions. */
3228 2 : lowlist_item = list_head(node->reflowerindexpr); /* could be NULL */
3229 4 : foreach(uplist_item, node->refupperindexpr)
3230 : {
3231 2 : appendStringInfoChar(buf, '[');
3232 2 : if (lowlist_item)
3233 : {
3234 0 : deparseExpr(lfirst(lowlist_item), context);
3235 0 : appendStringInfoChar(buf, ':');
3236 0 : lowlist_item = lnext(node->reflowerindexpr, lowlist_item);
3237 : }
3238 2 : deparseExpr(lfirst(uplist_item), context);
3239 2 : appendStringInfoChar(buf, ']');
3240 : }
3241 :
3242 2 : appendStringInfoChar(buf, ')');
3243 2 : }
3244 :
3245 : /*
3246 : * Deparse a function call.
3247 : */
3248 : static void
3249 116 : deparseFuncExpr(FuncExpr *node, deparse_expr_cxt *context)
3250 : {
3251 116 : StringInfo buf = context->buf;
3252 : bool use_variadic;
3253 : bool first;
3254 : ListCell *arg;
3255 :
3256 : /*
3257 : * If the function call came from an implicit coercion, then just show the
3258 : * first argument.
3259 : */
3260 116 : if (node->funcformat == COERCE_IMPLICIT_CAST)
3261 : {
3262 42 : deparseExpr((Expr *) linitial(node->args), context);
3263 42 : return;
3264 : }
3265 :
3266 : /*
3267 : * If the function call came from a cast, then show the first argument
3268 : * plus an explicit cast operation.
3269 : */
3270 74 : if (node->funcformat == COERCE_EXPLICIT_CAST)
3271 : {
3272 0 : Oid rettype = node->funcresulttype;
3273 : int32 coercedTypmod;
3274 :
3275 : /* Get the typmod if this is a length-coercion function */
3276 0 : (void) exprIsLengthCoercion((Node *) node, &coercedTypmod);
3277 :
3278 0 : deparseExpr((Expr *) linitial(node->args), context);
3279 0 : appendStringInfo(buf, "::%s",
3280 : deparse_type_name(rettype, coercedTypmod));
3281 0 : return;
3282 : }
3283 :
3284 : /* Check if need to print VARIADIC (cf. ruleutils.c) */
3285 74 : use_variadic = node->funcvariadic;
3286 :
3287 : /*
3288 : * Normal function: display as proname(args).
3289 : */
3290 74 : appendFunctionName(node->funcid, context);
3291 74 : appendStringInfoChar(buf, '(');
3292 :
3293 : /* ... and all the arguments */
3294 74 : first = true;
3295 156 : foreach(arg, node->args)
3296 : {
3297 82 : if (!first)
3298 8 : appendStringInfoString(buf, ", ");
3299 82 : if (use_variadic && lnext(node->args, arg) == NULL)
3300 0 : appendStringInfoString(buf, "VARIADIC ");
3301 82 : deparseExpr((Expr *) lfirst(arg), context);
3302 82 : first = false;
3303 : }
3304 74 : appendStringInfoChar(buf, ')');
3305 : }
3306 :
3307 : /*
3308 : * Deparse given operator expression. To avoid problems around
3309 : * priority of operations, we always parenthesize the arguments.
3310 : */
3311 : static void
3312 5554 : deparseOpExpr(OpExpr *node, deparse_expr_cxt *context)
3313 : {
3314 5554 : StringInfo buf = context->buf;
3315 : HeapTuple tuple;
3316 : Form_pg_operator form;
3317 : Expr *right;
3318 5554 : bool canSuppressRightConstCast = false;
3319 : char oprkind;
3320 :
3321 : /* Retrieve information about the operator from system catalog. */
3322 5554 : tuple = SearchSysCache1(OPEROID, ObjectIdGetDatum(node->opno));
3323 5554 : if (!HeapTupleIsValid(tuple))
3324 0 : elog(ERROR, "cache lookup failed for operator %u", node->opno);
3325 5554 : form = (Form_pg_operator) GETSTRUCT(tuple);
3326 5554 : oprkind = form->oprkind;
3327 :
3328 : /* Sanity check. */
3329 : Assert((oprkind == 'l' && list_length(node->args) == 1) ||
3330 : (oprkind == 'b' && list_length(node->args) == 2));
3331 :
3332 5554 : right = llast(node->args);
3333 :
3334 : /* Always parenthesize the expression. */
3335 5554 : appendStringInfoChar(buf, '(');
3336 :
3337 : /* Deparse left operand, if any. */
3338 5554 : if (oprkind == 'b')
3339 : {
3340 5548 : Expr *left = linitial(node->args);
3341 5548 : Oid leftType = exprType((Node *) left);
3342 5548 : Oid rightType = exprType((Node *) right);
3343 5548 : bool canSuppressLeftConstCast = false;
3344 :
3345 : /*
3346 : * When considering a binary operator, if one operand is a Const that
3347 : * can be printed as a bare string literal or NULL (i.e., it will look
3348 : * like type UNKNOWN to the remote parser), the Const normally
3349 : * receives an explicit cast to the operator's input type. However,
3350 : * in Const-to-Var comparisons where both operands are of the same
3351 : * type, we prefer to suppress the explicit cast, leaving the Const's
3352 : * type resolution up to the remote parser. The remote's resolution
3353 : * heuristic will assume that an unknown input type being compared to
3354 : * a known input type is of that known type as well.
3355 : *
3356 : * This hack allows some cases to succeed where a remote column is
3357 : * declared with a different type in the local (foreign) table. By
3358 : * emitting "foreigncol = 'foo'" not "foreigncol = 'foo'::text" or the
3359 : * like, we allow the remote parser to pick an "=" operator that's
3360 : * compatible with whatever type the remote column really is, such as
3361 : * an enum.
3362 : *
3363 : * We allow cast suppression to happen only when the other operand is
3364 : * a plain foreign Var. Although the remote's unknown-type heuristic
3365 : * would apply to other cases just as well, we would be taking a
3366 : * bigger risk that the inferred type is something unexpected. With
3367 : * this restriction, if anything goes wrong it's the user's fault for
3368 : * not declaring the local column with the same type as the remote
3369 : * column.
3370 : */
3371 5548 : if (leftType == rightType)
3372 : {
3373 5516 : if (IsA(left, Const))
3374 6 : canSuppressLeftConstCast = isPlainForeignVar(right, context);
3375 5510 : else if (IsA(right, Const))
3376 3086 : canSuppressRightConstCast = isPlainForeignVar(left, context);
3377 : }
3378 :
3379 5548 : if (canSuppressLeftConstCast)
3380 4 : deparseConst((Const *) left, context, -2);
3381 : else
3382 5544 : deparseExpr(left, context);
3383 :
3384 5548 : appendStringInfoChar(buf, ' ');
3385 : }
3386 :
3387 : /* Deparse operator name. */
3388 5554 : deparseOperatorName(buf, form);
3389 :
3390 : /* Deparse right operand. */
3391 5554 : appendStringInfoChar(buf, ' ');
3392 :
3393 5554 : if (canSuppressRightConstCast)
3394 2572 : deparseConst((Const *) right, context, -2);
3395 : else
3396 2982 : deparseExpr(right, context);
3397 :
3398 5554 : appendStringInfoChar(buf, ')');
3399 :
3400 5554 : ReleaseSysCache(tuple);
3401 5554 : }
3402 :
3403 : /*
3404 : * Will "node" deparse as a plain foreign Var?
3405 : */
3406 : static bool
3407 3092 : isPlainForeignVar(Expr *node, deparse_expr_cxt *context)
3408 : {
3409 : /*
3410 : * We allow the foreign Var to have an implicit RelabelType, mainly so
3411 : * that this'll work with varchar columns. Note that deparseRelabelType
3412 : * will not print such a cast, so we're not breaking the restriction that
3413 : * the expression print as a plain Var. We won't risk it for an implicit
3414 : * cast that requires a function, nor for non-implicit RelabelType; such
3415 : * cases seem too likely to involve semantics changes compared to what
3416 : * would happen on the remote side.
3417 : */
3418 3092 : if (IsA(node, RelabelType) &&
3419 10 : ((RelabelType *) node)->relabelformat == COERCE_IMPLICIT_CAST)
3420 10 : node = ((RelabelType *) node)->arg;
3421 :
3422 3092 : if (IsA(node, Var))
3423 : {
3424 : /*
3425 : * The Var must be one that'll deparse as a foreign column reference
3426 : * (cf. deparseVar).
3427 : */
3428 2576 : Var *var = (Var *) node;
3429 2576 : Relids relids = context->scanrel->relids;
3430 :
3431 2576 : if (bms_is_member(var->varno, relids) && var->varlevelsup == 0)
3432 2576 : return true;
3433 : }
3434 :
3435 516 : return false;
3436 : }
3437 :
3438 : /*
3439 : * Print the name of an operator.
3440 : */
3441 : static void
3442 5584 : deparseOperatorName(StringInfo buf, Form_pg_operator opform)
3443 : {
3444 : char *opname;
3445 :
3446 : /* opname is not a SQL identifier, so we should not quote it. */
3447 5584 : opname = NameStr(opform->oprname);
3448 :
3449 : /* Print schema name only if it's not pg_catalog */
3450 5584 : if (opform->oprnamespace != PG_CATALOG_NAMESPACE)
3451 : {
3452 : const char *opnspname;
3453 :
3454 26 : opnspname = get_namespace_name(opform->oprnamespace);
3455 : /* Print fully qualified operator name. */
3456 26 : appendStringInfo(buf, "OPERATOR(%s.%s)",
3457 : quote_identifier(opnspname), opname);
3458 : }
3459 : else
3460 : {
3461 : /* Just print operator name. */
3462 5558 : appendStringInfoString(buf, opname);
3463 : }
3464 5584 : }
3465 :
3466 : /*
3467 : * Deparse IS DISTINCT FROM.
3468 : */
3469 : static void
3470 2 : deparseDistinctExpr(DistinctExpr *node, deparse_expr_cxt *context)
3471 : {
3472 2 : StringInfo buf = context->buf;
3473 :
3474 : Assert(list_length(node->args) == 2);
3475 :
3476 2 : appendStringInfoChar(buf, '(');
3477 2 : deparseExpr(linitial(node->args), context);
3478 2 : appendStringInfoString(buf, " IS DISTINCT FROM ");
3479 2 : deparseExpr(lsecond(node->args), context);
3480 2 : appendStringInfoChar(buf, ')');
3481 2 : }
3482 :
3483 : /*
3484 : * Deparse given ScalarArrayOpExpr expression. To avoid problems
3485 : * around priority of operations, we always parenthesize the arguments.
3486 : */
3487 : static void
3488 14 : deparseScalarArrayOpExpr(ScalarArrayOpExpr *node, deparse_expr_cxt *context)
3489 : {
3490 14 : StringInfo buf = context->buf;
3491 : HeapTuple tuple;
3492 : Form_pg_operator form;
3493 : Expr *arg1;
3494 : Expr *arg2;
3495 :
3496 : /* Retrieve information about the operator from system catalog. */
3497 14 : tuple = SearchSysCache1(OPEROID, ObjectIdGetDatum(node->opno));
3498 14 : if (!HeapTupleIsValid(tuple))
3499 0 : elog(ERROR, "cache lookup failed for operator %u", node->opno);
3500 14 : form = (Form_pg_operator) GETSTRUCT(tuple);
3501 :
3502 : /* Sanity check. */
3503 : Assert(list_length(node->args) == 2);
3504 :
3505 : /* Always parenthesize the expression. */
3506 14 : appendStringInfoChar(buf, '(');
3507 :
3508 : /* Deparse left operand. */
3509 14 : arg1 = linitial(node->args);
3510 14 : deparseExpr(arg1, context);
3511 14 : appendStringInfoChar(buf, ' ');
3512 :
3513 : /* Deparse operator name plus decoration. */
3514 14 : deparseOperatorName(buf, form);
3515 14 : appendStringInfo(buf, " %s (", node->useOr ? "ANY" : "ALL");
3516 :
3517 : /* Deparse right operand. */
3518 14 : arg2 = lsecond(node->args);
3519 14 : deparseExpr(arg2, context);
3520 :
3521 14 : appendStringInfoChar(buf, ')');
3522 :
3523 : /* Always parenthesize the expression. */
3524 14 : appendStringInfoChar(buf, ')');
3525 :
3526 14 : ReleaseSysCache(tuple);
3527 14 : }
3528 :
3529 : /*
3530 : * Deparse a RelabelType (binary-compatible cast) node.
3531 : */
3532 : static void
3533 72 : deparseRelabelType(RelabelType *node, deparse_expr_cxt *context)
3534 : {
3535 72 : deparseExpr(node->arg, context);
3536 72 : if (node->relabelformat != COERCE_IMPLICIT_CAST)
3537 0 : appendStringInfo(context->buf, "::%s",
3538 : deparse_type_name(node->resulttype,
3539 : node->resulttypmod));
3540 72 : }
3541 :
3542 : /*
3543 : * Deparse an ArrayCoerceExpr (array-type conversion) node.
3544 : */
3545 : static void
3546 6 : deparseArrayCoerceExpr(ArrayCoerceExpr *node, deparse_expr_cxt *context)
3547 : {
3548 6 : deparseExpr(node->arg, context);
3549 :
3550 : /*
3551 : * No difference how to deparse explicit cast, but if we omit implicit
3552 : * cast in the query, it'll be more user-friendly
3553 : */
3554 6 : if (node->coerceformat != COERCE_IMPLICIT_CAST)
3555 0 : appendStringInfo(context->buf, "::%s",
3556 : deparse_type_name(node->resulttype,
3557 : node->resulttypmod));
3558 6 : }
3559 :
3560 : /*
3561 : * Deparse a BoolExpr node.
3562 : */
3563 : static void
3564 76 : deparseBoolExpr(BoolExpr *node, deparse_expr_cxt *context)
3565 : {
3566 76 : StringInfo buf = context->buf;
3567 76 : const char *op = NULL; /* keep compiler quiet */
3568 : bool first;
3569 : ListCell *lc;
3570 :
3571 76 : switch (node->boolop)
3572 : {
3573 36 : case AND_EXPR:
3574 36 : op = "AND";
3575 36 : break;
3576 40 : case OR_EXPR:
3577 40 : op = "OR";
3578 40 : break;
3579 0 : case NOT_EXPR:
3580 0 : appendStringInfoString(buf, "(NOT ");
3581 0 : deparseExpr(linitial(node->args), context);
3582 0 : appendStringInfoChar(buf, ')');
3583 0 : return;
3584 : }
3585 :
3586 76 : appendStringInfoChar(buf, '(');
3587 76 : first = true;
3588 228 : foreach(lc, node->args)
3589 : {
3590 152 : if (!first)
3591 76 : appendStringInfo(buf, " %s ", op);
3592 152 : deparseExpr((Expr *) lfirst(lc), context);
3593 152 : first = false;
3594 : }
3595 76 : appendStringInfoChar(buf, ')');
3596 : }
3597 :
3598 : /*
3599 : * Deparse IS [NOT] NULL expression.
3600 : */
3601 : static void
3602 56 : deparseNullTest(NullTest *node, deparse_expr_cxt *context)
3603 : {
3604 56 : StringInfo buf = context->buf;
3605 :
3606 56 : appendStringInfoChar(buf, '(');
3607 56 : deparseExpr(node->arg, context);
3608 :
3609 : /*
3610 : * For scalar inputs, we prefer to print as IS [NOT] NULL, which is
3611 : * shorter and traditional. If it's a rowtype input but we're applying a
3612 : * scalar test, must print IS [NOT] DISTINCT FROM NULL to be semantically
3613 : * correct.
3614 : */
3615 56 : if (node->argisrow || !type_is_rowtype(exprType((Node *) node->arg)))
3616 : {
3617 56 : if (node->nulltesttype == IS_NULL)
3618 38 : appendStringInfoString(buf, " IS NULL)");
3619 : else
3620 18 : appendStringInfoString(buf, " IS NOT NULL)");
3621 : }
3622 : else
3623 : {
3624 0 : if (node->nulltesttype == IS_NULL)
3625 0 : appendStringInfoString(buf, " IS NOT DISTINCT FROM NULL)");
3626 : else
3627 0 : appendStringInfoString(buf, " IS DISTINCT FROM NULL)");
3628 : }
3629 56 : }
3630 :
3631 : /*
3632 : * Deparse CASE expression
3633 : */
3634 : static void
3635 42 : deparseCaseExpr(CaseExpr *node, deparse_expr_cxt *context)
3636 : {
3637 42 : StringInfo buf = context->buf;
3638 : ListCell *lc;
3639 :
3640 42 : appendStringInfoString(buf, "(CASE");
3641 :
3642 : /* If this is a CASE arg WHEN then emit the arg expression */
3643 42 : if (node->arg != NULL)
3644 : {
3645 18 : appendStringInfoChar(buf, ' ');
3646 18 : deparseExpr(node->arg, context);
3647 : }
3648 :
3649 : /* Add each condition/result of the CASE clause */
3650 98 : foreach(lc, node->args)
3651 : {
3652 56 : CaseWhen *whenclause = (CaseWhen *) lfirst(lc);
3653 :
3654 : /* WHEN */
3655 56 : appendStringInfoString(buf, " WHEN ");
3656 56 : if (node->arg == NULL) /* CASE WHEN */
3657 24 : deparseExpr(whenclause->expr, context);
3658 : else /* CASE arg WHEN */
3659 : {
3660 : /* Ignore the CaseTestExpr and equality operator. */
3661 32 : deparseExpr(lsecond(castNode(OpExpr, whenclause->expr)->args),
3662 : context);
3663 : }
3664 :
3665 : /* THEN */
3666 56 : appendStringInfoString(buf, " THEN ");
3667 56 : deparseExpr(whenclause->result, context);
3668 : }
3669 :
3670 : /* add ELSE if present */
3671 42 : if (node->defresult != NULL)
3672 : {
3673 42 : appendStringInfoString(buf, " ELSE ");
3674 42 : deparseExpr(node->defresult, context);
3675 : }
3676 :
3677 : /* append END */
3678 42 : appendStringInfoString(buf, " END)");
3679 42 : }
3680 :
3681 : /*
3682 : * Deparse ARRAY[...] construct.
3683 : */
3684 : static void
3685 8 : deparseArrayExpr(ArrayExpr *node, deparse_expr_cxt *context)
3686 : {
3687 8 : StringInfo buf = context->buf;
3688 8 : bool first = true;
3689 : ListCell *lc;
3690 :
3691 8 : appendStringInfoString(buf, "ARRAY[");
3692 24 : foreach(lc, node->elements)
3693 : {
3694 16 : if (!first)
3695 8 : appendStringInfoString(buf, ", ");
3696 16 : deparseExpr(lfirst(lc), context);
3697 16 : first = false;
3698 : }
3699 8 : appendStringInfoChar(buf, ']');
3700 :
3701 : /* If the array is empty, we need an explicit cast to the array type. */
3702 8 : if (node->elements == NIL)
3703 0 : appendStringInfo(buf, "::%s",
3704 : deparse_type_name(node->array_typeid, -1));
3705 8 : }
3706 :
3707 : /*
3708 : * Deparse an Aggref node.
3709 : */
3710 : static void
3711 526 : deparseAggref(Aggref *node, deparse_expr_cxt *context)
3712 : {
3713 526 : StringInfo buf = context->buf;
3714 : bool use_variadic;
3715 :
3716 : /* Only basic, non-split aggregation accepted. */
3717 : Assert(node->aggsplit == AGGSPLIT_SIMPLE);
3718 :
3719 : /* Check if need to print VARIADIC (cf. ruleutils.c) */
3720 526 : use_variadic = node->aggvariadic;
3721 :
3722 : /* Find aggregate name from aggfnoid which is a pg_proc entry */
3723 526 : appendFunctionName(node->aggfnoid, context);
3724 526 : appendStringInfoChar(buf, '(');
3725 :
3726 : /* Add DISTINCT */
3727 526 : appendStringInfoString(buf, (node->aggdistinct != NIL) ? "DISTINCT " : "");
3728 :
3729 526 : if (AGGKIND_IS_ORDERED_SET(node->aggkind))
3730 : {
3731 : /* Add WITHIN GROUP (ORDER BY ..) */
3732 : ListCell *arg;
3733 16 : bool first = true;
3734 :
3735 : Assert(!node->aggvariadic);
3736 : Assert(node->aggorder != NIL);
3737 :
3738 36 : foreach(arg, node->aggdirectargs)
3739 : {
3740 20 : if (!first)
3741 4 : appendStringInfoString(buf, ", ");
3742 20 : first = false;
3743 :
3744 20 : deparseExpr((Expr *) lfirst(arg), context);
3745 : }
3746 :
3747 16 : appendStringInfoString(buf, ") WITHIN GROUP (ORDER BY ");
3748 16 : appendAggOrderBy(node->aggorder, node->args, context);
3749 : }
3750 : else
3751 : {
3752 : /* aggstar can be set only in zero-argument aggregates */
3753 510 : if (node->aggstar)
3754 140 : appendStringInfoChar(buf, '*');
3755 : else
3756 : {
3757 : ListCell *arg;
3758 370 : bool first = true;
3759 :
3760 : /* Add all the arguments */
3761 748 : foreach(arg, node->args)
3762 : {
3763 378 : TargetEntry *tle = (TargetEntry *) lfirst(arg);
3764 378 : Node *n = (Node *) tle->expr;
3765 :
3766 378 : if (tle->resjunk)
3767 8 : continue;
3768 :
3769 370 : if (!first)
3770 0 : appendStringInfoString(buf, ", ");
3771 370 : first = false;
3772 :
3773 : /* Add VARIADIC */
3774 370 : if (use_variadic && lnext(node->args, arg) == NULL)
3775 4 : appendStringInfoString(buf, "VARIADIC ");
3776 :
3777 370 : deparseExpr((Expr *) n, context);
3778 : }
3779 : }
3780 :
3781 : /* Add ORDER BY */
3782 510 : if (node->aggorder != NIL)
3783 : {
3784 44 : appendStringInfoString(buf, " ORDER BY ");
3785 44 : appendAggOrderBy(node->aggorder, node->args, context);
3786 : }
3787 : }
3788 :
3789 : /* Add FILTER (WHERE ..) */
3790 526 : if (node->aggfilter != NULL)
3791 : {
3792 24 : appendStringInfoString(buf, ") FILTER (WHERE ");
3793 24 : deparseExpr((Expr *) node->aggfilter, context);
3794 : }
3795 :
3796 526 : appendStringInfoChar(buf, ')');
3797 526 : }
3798 :
3799 : /*
3800 : * Append ORDER BY within aggregate function.
3801 : */
3802 : static void
3803 60 : appendAggOrderBy(List *orderList, List *targetList, deparse_expr_cxt *context)
3804 : {
3805 60 : StringInfo buf = context->buf;
3806 : ListCell *lc;
3807 60 : bool first = true;
3808 :
3809 124 : foreach(lc, orderList)
3810 : {
3811 64 : SortGroupClause *srt = (SortGroupClause *) lfirst(lc);
3812 : Node *sortexpr;
3813 :
3814 64 : if (!first)
3815 4 : appendStringInfoString(buf, ", ");
3816 64 : first = false;
3817 :
3818 : /* Deparse the sort expression proper. */
3819 64 : sortexpr = deparseSortGroupClause(srt->tleSortGroupRef, targetList,
3820 : false, context);
3821 : /* Add decoration as needed. */
3822 64 : appendOrderBySuffix(srt->sortop, exprType(sortexpr), srt->nulls_first,
3823 : context);
3824 : }
3825 60 : }
3826 :
3827 : /*
3828 : * Append the ASC, DESC, USING <OPERATOR> and NULLS FIRST / NULLS LAST parts
3829 : * of an ORDER BY clause.
3830 : */
3831 : static void
3832 1792 : appendOrderBySuffix(Oid sortop, Oid sortcoltype, bool nulls_first,
3833 : deparse_expr_cxt *context)
3834 : {
3835 1792 : StringInfo buf = context->buf;
3836 : TypeCacheEntry *typentry;
3837 :
3838 : /* See whether operator is default < or > for sort expr's datatype. */
3839 1792 : typentry = lookup_type_cache(sortcoltype,
3840 : TYPECACHE_LT_OPR | TYPECACHE_GT_OPR);
3841 :
3842 1792 : if (sortop == typentry->lt_opr)
3843 1746 : appendStringInfoString(buf, " ASC");
3844 46 : else if (sortop == typentry->gt_opr)
3845 30 : appendStringInfoString(buf, " DESC");
3846 : else
3847 : {
3848 : HeapTuple opertup;
3849 : Form_pg_operator operform;
3850 :
3851 16 : appendStringInfoString(buf, " USING ");
3852 :
3853 : /* Append operator name. */
3854 16 : opertup = SearchSysCache1(OPEROID, ObjectIdGetDatum(sortop));
3855 16 : if (!HeapTupleIsValid(opertup))
3856 0 : elog(ERROR, "cache lookup failed for operator %u", sortop);
3857 16 : operform = (Form_pg_operator) GETSTRUCT(opertup);
3858 16 : deparseOperatorName(buf, operform);
3859 16 : ReleaseSysCache(opertup);
3860 : }
3861 :
3862 1792 : if (nulls_first)
3863 22 : appendStringInfoString(buf, " NULLS FIRST");
3864 : else
3865 1770 : appendStringInfoString(buf, " NULLS LAST");
3866 1792 : }
3867 :
3868 : /*
3869 : * Print the representation of a parameter to be sent to the remote side.
3870 : *
3871 : * Note: we always label the Param's type explicitly rather than relying on
3872 : * transmitting a numeric type OID in PQsendQueryParams(). This allows us to
3873 : * avoid assuming that types have the same OIDs on the remote side as they
3874 : * do locally --- they need only have the same names.
3875 : */
3876 : static void
3877 60 : printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod,
3878 : deparse_expr_cxt *context)
3879 : {
3880 60 : StringInfo buf = context->buf;
3881 60 : char *ptypename = deparse_type_name(paramtype, paramtypmod);
3882 :
3883 60 : appendStringInfo(buf, "$%d::%s", paramindex, ptypename);
3884 60 : }
3885 :
3886 : /*
3887 : * Print the representation of a placeholder for a parameter that will be
3888 : * sent to the remote side at execution time.
3889 : *
3890 : * This is used when we're just trying to EXPLAIN the remote query.
3891 : * We don't have the actual value of the runtime parameter yet, and we don't
3892 : * want the remote planner to generate a plan that depends on such a value
3893 : * anyway. Thus, we can't do something simple like "$1::paramtype".
3894 : * Instead, we emit "((SELECT null::paramtype)::paramtype)".
3895 : * In all extant versions of Postgres, the planner will see that as an unknown
3896 : * constant value, which is what we want. This might need adjustment if we
3897 : * ever make the planner flatten scalar subqueries. Note: the reason for the
3898 : * apparently useless outer cast is to ensure that the representation as a
3899 : * whole will be parsed as an a_expr and not a select_with_parens; the latter
3900 : * would do the wrong thing in the context "x = ANY(...)".
3901 : */
3902 : static void
3903 432 : printRemotePlaceholder(Oid paramtype, int32 paramtypmod,
3904 : deparse_expr_cxt *context)
3905 : {
3906 432 : StringInfo buf = context->buf;
3907 432 : char *ptypename = deparse_type_name(paramtype, paramtypmod);
3908 :
3909 432 : appendStringInfo(buf, "((SELECT null::%s)::%s)", ptypename, ptypename);
3910 432 : }
3911 :
3912 : /*
3913 : * Deparse GROUP BY clause.
3914 : */
3915 : static void
3916 332 : appendGroupByClause(List *tlist, deparse_expr_cxt *context)
3917 : {
3918 332 : StringInfo buf = context->buf;
3919 332 : Query *query = context->root->parse;
3920 : ListCell *lc;
3921 332 : bool first = true;
3922 :
3923 : /* Nothing to be done, if there's no GROUP BY clause in the query. */
3924 332 : if (!query->groupClause)
3925 130 : return;
3926 :
3927 202 : appendStringInfoString(buf, " GROUP BY ");
3928 :
3929 : /*
3930 : * Queries with grouping sets are not pushed down, so we don't expect
3931 : * grouping sets here.
3932 : */
3933 : Assert(!query->groupingSets);
3934 :
3935 : /*
3936 : * We intentionally print query->groupClause not processed_groupClause,
3937 : * leaving it to the remote planner to get rid of any redundant GROUP BY
3938 : * items again. This is necessary in case processed_groupClause reduced
3939 : * to empty, and in any case the redundancy situation on the remote might
3940 : * be different than what we think here.
3941 : */
3942 428 : foreach(lc, query->groupClause)
3943 : {
3944 226 : SortGroupClause *grp = (SortGroupClause *) lfirst(lc);
3945 :
3946 226 : if (!first)
3947 24 : appendStringInfoString(buf, ", ");
3948 226 : first = false;
3949 :
3950 226 : deparseSortGroupClause(grp->tleSortGroupRef, tlist, true, context);
3951 : }
3952 : }
3953 :
3954 : /*
3955 : * Deparse ORDER BY clause defined by the given pathkeys.
3956 : *
3957 : * The clause should use Vars from context->scanrel if !has_final_sort,
3958 : * or from context->foreignrel's targetlist if has_final_sort.
3959 : *
3960 : * We find a suitable pathkey expression (some earlier step
3961 : * should have verified that there is one) and deparse it.
3962 : */
3963 : static void
3964 1474 : appendOrderByClause(List *pathkeys, bool has_final_sort,
3965 : deparse_expr_cxt *context)
3966 : {
3967 : ListCell *lcell;
3968 : int nestlevel;
3969 1474 : StringInfo buf = context->buf;
3970 1474 : bool gotone = false;
3971 :
3972 : /* Make sure any constants in the exprs are printed portably */
3973 1474 : nestlevel = set_transmission_modes();
3974 :
3975 3214 : foreach(lcell, pathkeys)
3976 : {
3977 1740 : PathKey *pathkey = lfirst(lcell);
3978 : EquivalenceMember *em;
3979 : Expr *em_expr;
3980 : Oid oprid;
3981 :
3982 1740 : if (has_final_sort)
3983 : {
3984 : /*
3985 : * By construction, context->foreignrel is the input relation to
3986 : * the final sort.
3987 : */
3988 414 : em = find_em_for_rel_target(context->root,
3989 : pathkey->pk_eclass,
3990 : context->foreignrel);
3991 : }
3992 : else
3993 1326 : em = find_em_for_rel(context->root,
3994 : pathkey->pk_eclass,
3995 : context->scanrel);
3996 :
3997 : /*
3998 : * We don't expect any error here; it would mean that shippability
3999 : * wasn't verified earlier. For the same reason, we don't recheck
4000 : * shippability of the sort operator.
4001 : */
4002 1740 : if (em == NULL)
4003 0 : elog(ERROR, "could not find pathkey item to sort");
4004 :
4005 1740 : em_expr = em->em_expr;
4006 :
4007 : /*
4008 : * If the member is a Const expression then we needn't add it to the
4009 : * ORDER BY clause. This can happen in UNION ALL queries where the
4010 : * union child targetlist has a Const. Adding these would be
4011 : * wasteful, but also, for INT columns, an integer literal would be
4012 : * seen as an ordinal column position rather than a value to sort by.
4013 : * deparseConst() does have code to handle this, but it seems less
4014 : * effort on all accounts just to skip these for ORDER BY clauses.
4015 : */
4016 1740 : if (IsA(em_expr, Const))
4017 12 : continue;
4018 :
4019 1728 : if (!gotone)
4020 : {
4021 1468 : appendStringInfoString(buf, " ORDER BY ");
4022 1468 : gotone = true;
4023 : }
4024 : else
4025 260 : appendStringInfoString(buf, ", ");
4026 :
4027 : /*
4028 : * Lookup the operator corresponding to the compare type in the
4029 : * opclass. The datatype used by the opfamily is not necessarily the
4030 : * same as the expression type (for array types for example).
4031 : */
4032 1728 : oprid = get_opfamily_member_for_cmptype(pathkey->pk_opfamily,
4033 : em->em_datatype,
4034 : em->em_datatype,
4035 : pathkey->pk_cmptype);
4036 1728 : if (!OidIsValid(oprid))
4037 0 : elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
4038 : pathkey->pk_cmptype, em->em_datatype, em->em_datatype,
4039 : pathkey->pk_opfamily);
4040 :
4041 1728 : deparseExpr(em_expr, context);
4042 :
4043 : /*
4044 : * Here we need to use the expression's actual type to discover
4045 : * whether the desired operator will be the default or not.
4046 : */
4047 1728 : appendOrderBySuffix(oprid, exprType((Node *) em_expr),
4048 1728 : pathkey->pk_nulls_first, context);
4049 :
4050 : }
4051 1474 : reset_transmission_modes(nestlevel);
4052 1474 : }
4053 :
4054 : /*
4055 : * Deparse LIMIT/OFFSET clause.
4056 : */
4057 : static void
4058 292 : appendLimitClause(deparse_expr_cxt *context)
4059 : {
4060 292 : PlannerInfo *root = context->root;
4061 292 : StringInfo buf = context->buf;
4062 : int nestlevel;
4063 :
4064 : /* Make sure any constants in the exprs are printed portably */
4065 292 : nestlevel = set_transmission_modes();
4066 :
4067 292 : if (root->parse->limitCount)
4068 : {
4069 292 : appendStringInfoString(buf, " LIMIT ");
4070 292 : deparseExpr((Expr *) root->parse->limitCount, context);
4071 : }
4072 292 : if (root->parse->limitOffset)
4073 : {
4074 150 : appendStringInfoString(buf, " OFFSET ");
4075 150 : deparseExpr((Expr *) root->parse->limitOffset, context);
4076 : }
4077 :
4078 292 : reset_transmission_modes(nestlevel);
4079 292 : }
4080 :
4081 : /*
4082 : * appendFunctionName
4083 : * Deparses function name from given function oid.
4084 : */
4085 : static void
4086 600 : appendFunctionName(Oid funcid, deparse_expr_cxt *context)
4087 : {
4088 600 : StringInfo buf = context->buf;
4089 : HeapTuple proctup;
4090 : Form_pg_proc procform;
4091 : const char *proname;
4092 :
4093 600 : proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
4094 600 : if (!HeapTupleIsValid(proctup))
4095 0 : elog(ERROR, "cache lookup failed for function %u", funcid);
4096 600 : procform = (Form_pg_proc) GETSTRUCT(proctup);
4097 :
4098 : /* Print schema name only if it's not pg_catalog */
4099 600 : if (procform->pronamespace != PG_CATALOG_NAMESPACE)
4100 : {
4101 : const char *schemaname;
4102 :
4103 12 : schemaname = get_namespace_name(procform->pronamespace);
4104 12 : appendStringInfo(buf, "%s.", quote_identifier(schemaname));
4105 : }
4106 :
4107 : /* Always print the function name */
4108 600 : proname = NameStr(procform->proname);
4109 600 : appendStringInfoString(buf, quote_identifier(proname));
4110 :
4111 600 : ReleaseSysCache(proctup);
4112 600 : }
4113 :
4114 : /*
4115 : * Appends a sort or group clause.
4116 : *
4117 : * Like get_rule_sortgroupclause(), returns the expression tree, so caller
4118 : * need not find it again.
4119 : */
4120 : static Node *
4121 290 : deparseSortGroupClause(Index ref, List *tlist, bool force_colno,
4122 : deparse_expr_cxt *context)
4123 : {
4124 290 : StringInfo buf = context->buf;
4125 : TargetEntry *tle;
4126 : Expr *expr;
4127 :
4128 290 : tle = get_sortgroupref_tle(ref, tlist);
4129 290 : expr = tle->expr;
4130 :
4131 290 : if (force_colno)
4132 : {
4133 : /* Use column-number form when requested by caller. */
4134 : Assert(!tle->resjunk);
4135 226 : appendStringInfo(buf, "%d", tle->resno);
4136 : }
4137 64 : else if (expr && IsA(expr, Const))
4138 : {
4139 : /*
4140 : * Force a typecast here so that we don't emit something like "GROUP
4141 : * BY 2", which will be misconstrued as a column position rather than
4142 : * a constant.
4143 : */
4144 0 : deparseConst((Const *) expr, context, 1);
4145 : }
4146 64 : else if (!expr || IsA(expr, Var))
4147 36 : deparseExpr(expr, context);
4148 : else
4149 : {
4150 : /* Always parenthesize the expression. */
4151 28 : appendStringInfoChar(buf, '(');
4152 28 : deparseExpr(expr, context);
4153 28 : appendStringInfoChar(buf, ')');
4154 : }
4155 :
4156 290 : return (Node *) expr;
4157 : }
4158 :
4159 :
4160 : /*
4161 : * Returns true if given Var is deparsed as a subquery output column, in
4162 : * which case, *relno and *colno are set to the IDs for the relation and
4163 : * column alias to the Var provided by the subquery.
4164 : */
4165 : static bool
4166 17244 : is_subquery_var(Var *node, RelOptInfo *foreignrel, int *relno, int *colno)
4167 : {
4168 17244 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
4169 17244 : RelOptInfo *outerrel = fpinfo->outerrel;
4170 17244 : RelOptInfo *innerrel = fpinfo->innerrel;
4171 :
4172 : /* Should only be called in these cases. */
4173 : Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
4174 :
4175 : /*
4176 : * If the given relation isn't a join relation, it doesn't have any lower
4177 : * subqueries, so the Var isn't a subquery output column.
4178 : */
4179 17244 : if (!IS_JOIN_REL(foreignrel))
4180 4116 : return false;
4181 :
4182 : /*
4183 : * If the Var doesn't belong to any lower subqueries, it isn't a subquery
4184 : * output column.
4185 : */
4186 13128 : if (!bms_is_member(node->varno, fpinfo->lower_subquery_rels))
4187 12796 : return false;
4188 :
4189 332 : if (bms_is_member(node->varno, outerrel->relids))
4190 : {
4191 : /*
4192 : * If outer relation is deparsed as a subquery, the Var is an output
4193 : * column of the subquery; get the IDs for the relation/column alias.
4194 : */
4195 112 : if (fpinfo->make_outerrel_subquery)
4196 : {
4197 84 : get_relation_column_alias_ids(node, outerrel, relno, colno);
4198 84 : return true;
4199 : }
4200 :
4201 : /* Otherwise, recurse into the outer relation. */
4202 28 : return is_subquery_var(node, outerrel, relno, colno);
4203 : }
4204 : else
4205 : {
4206 : Assert(bms_is_member(node->varno, innerrel->relids));
4207 :
4208 : /*
4209 : * If inner relation is deparsed as a subquery, the Var is an output
4210 : * column of the subquery; get the IDs for the relation/column alias.
4211 : */
4212 220 : if (fpinfo->make_innerrel_subquery)
4213 : {
4214 220 : get_relation_column_alias_ids(node, innerrel, relno, colno);
4215 220 : return true;
4216 : }
4217 :
4218 : /* Otherwise, recurse into the inner relation. */
4219 0 : return is_subquery_var(node, innerrel, relno, colno);
4220 : }
4221 : }
4222 :
4223 : /*
4224 : * Get the IDs for the relation and column alias to given Var belonging to
4225 : * given relation, which are returned into *relno and *colno.
4226 : */
4227 : static void
4228 304 : get_relation_column_alias_ids(Var *node, RelOptInfo *foreignrel,
4229 : int *relno, int *colno)
4230 : {
4231 304 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
4232 : int i;
4233 : ListCell *lc;
4234 :
4235 : /* Get the relation alias ID */
4236 304 : *relno = fpinfo->relation_index;
4237 :
4238 : /* Get the column alias ID */
4239 304 : i = 1;
4240 376 : foreach(lc, foreignrel->reltarget->exprs)
4241 : {
4242 376 : Var *tlvar = (Var *) lfirst(lc);
4243 :
4244 : /*
4245 : * Match reltarget entries only on varno/varattno. Ideally there
4246 : * would be some cross-check on varnullingrels, but it's unclear what
4247 : * to do exactly; we don't have enough context to know what that value
4248 : * should be.
4249 : */
4250 376 : if (IsA(tlvar, Var) &&
4251 376 : tlvar->varno == node->varno &&
4252 360 : tlvar->varattno == node->varattno)
4253 : {
4254 304 : *colno = i;
4255 304 : return;
4256 : }
4257 72 : i++;
4258 : }
4259 :
4260 : /* Shouldn't get here */
4261 0 : elog(ERROR, "unexpected expression in subquery output");
4262 : }
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