Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * appendinfo.c
4 : * Routines for mapping between append parent(s) and children
5 : *
6 : * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
7 : * Portions Copyright (c) 1994, Regents of the University of California
8 : *
9 : *
10 : * IDENTIFICATION
11 : * src/backend/optimizer/util/appendinfo.c
12 : *
13 : *-------------------------------------------------------------------------
14 : */
15 : #include "postgres.h"
16 :
17 : #include "access/htup_details.h"
18 : #include "access/table.h"
19 : #include "foreign/fdwapi.h"
20 : #include "nodes/makefuncs.h"
21 : #include "nodes/nodeFuncs.h"
22 : #include "optimizer/appendinfo.h"
23 : #include "optimizer/pathnode.h"
24 : #include "optimizer/planmain.h"
25 : #include "parser/parsetree.h"
26 : #include "utils/lsyscache.h"
27 : #include "utils/rel.h"
28 : #include "utils/syscache.h"
29 :
30 :
31 : typedef struct
32 : {
33 : PlannerInfo *root;
34 : int nappinfos;
35 : AppendRelInfo **appinfos;
36 : } adjust_appendrel_attrs_context;
37 :
38 : static void make_inh_translation_list(Relation oldrelation,
39 : Relation newrelation,
40 : Index newvarno,
41 : AppendRelInfo *appinfo);
42 : static Node *adjust_appendrel_attrs_mutator(Node *node,
43 : adjust_appendrel_attrs_context *context);
44 :
45 :
46 : /*
47 : * make_append_rel_info
48 : * Build an AppendRelInfo for the parent-child pair
49 : */
50 : AppendRelInfo *
51 39238 : make_append_rel_info(Relation parentrel, Relation childrel,
52 : Index parentRTindex, Index childRTindex)
53 : {
54 39238 : AppendRelInfo *appinfo = makeNode(AppendRelInfo);
55 :
56 39238 : appinfo->parent_relid = parentRTindex;
57 39238 : appinfo->child_relid = childRTindex;
58 39238 : appinfo->parent_reltype = parentrel->rd_rel->reltype;
59 39238 : appinfo->child_reltype = childrel->rd_rel->reltype;
60 39238 : make_inh_translation_list(parentrel, childrel, childRTindex, appinfo);
61 39236 : appinfo->parent_reloid = RelationGetRelid(parentrel);
62 :
63 39236 : return appinfo;
64 : }
65 :
66 : /*
67 : * make_inh_translation_list
68 : * Build the list of translations from parent Vars to child Vars for
69 : * an inheritance child, as well as a reverse-translation array.
70 : *
71 : * The reverse-translation array has an entry for each child relation
72 : * column, which is either the 1-based index of the corresponding parent
73 : * column, or 0 if there's no match (that happens for dropped child columns,
74 : * as well as child columns beyond those of the parent, which are allowed in
75 : * traditional inheritance though not partitioning).
76 : *
77 : * For paranoia's sake, we match type/collation as well as attribute name.
78 : */
79 : static void
80 39238 : make_inh_translation_list(Relation oldrelation, Relation newrelation,
81 : Index newvarno,
82 : AppendRelInfo *appinfo)
83 : {
84 39238 : List *vars = NIL;
85 : AttrNumber *pcolnos;
86 39238 : TupleDesc old_tupdesc = RelationGetDescr(oldrelation);
87 39238 : TupleDesc new_tupdesc = RelationGetDescr(newrelation);
88 39238 : Oid new_relid = RelationGetRelid(newrelation);
89 39238 : int oldnatts = old_tupdesc->natts;
90 39238 : int newnatts = new_tupdesc->natts;
91 : int old_attno;
92 39238 : int new_attno = 0;
93 :
94 : /* Initialize reverse-translation array with all entries zero */
95 39238 : appinfo->num_child_cols = newnatts;
96 39238 : appinfo->parent_colnos = pcolnos =
97 39238 : (AttrNumber *) palloc0(newnatts * sizeof(AttrNumber));
98 :
99 146260 : for (old_attno = 0; old_attno < oldnatts; old_attno++)
100 : {
101 : Form_pg_attribute att;
102 : char *attname;
103 : Oid atttypid;
104 : int32 atttypmod;
105 : Oid attcollation;
106 :
107 107024 : att = TupleDescAttr(old_tupdesc, old_attno);
108 107024 : if (att->attisdropped)
109 : {
110 : /* Just put NULL into this list entry */
111 3108 : vars = lappend(vars, NULL);
112 3108 : continue;
113 : }
114 103916 : attname = NameStr(att->attname);
115 103916 : atttypid = att->atttypid;
116 103916 : atttypmod = att->atttypmod;
117 103916 : attcollation = att->attcollation;
118 :
119 : /*
120 : * When we are generating the "translation list" for the parent table
121 : * of an inheritance set, no need to search for matches.
122 : */
123 103916 : if (oldrelation == newrelation)
124 : {
125 6298 : vars = lappend(vars, makeVar(newvarno,
126 6298 : (AttrNumber) (old_attno + 1),
127 : atttypid,
128 : atttypmod,
129 : attcollation,
130 : 0));
131 6298 : pcolnos[old_attno] = old_attno + 1;
132 6298 : continue;
133 : }
134 :
135 : /*
136 : * Otherwise we have to search for the matching column by name.
137 : * There's no guarantee it'll have the same column position, because
138 : * of cases like ALTER TABLE ADD COLUMN and multiple inheritance.
139 : * However, in simple cases, the relative order of columns is mostly
140 : * the same in both relations, so try the column of newrelation that
141 : * follows immediately after the one that we just found, and if that
142 : * fails, let syscache handle it.
143 : */
144 97618 : if (new_attno >= newnatts ||
145 95444 : (att = TupleDescAttr(new_tupdesc, new_attno))->attisdropped ||
146 94546 : strcmp(attname, NameStr(att->attname)) != 0)
147 : {
148 : HeapTuple newtup;
149 :
150 7762 : newtup = SearchSysCacheAttName(new_relid, attname);
151 7762 : if (!HeapTupleIsValid(newtup))
152 0 : elog(ERROR, "could not find inherited attribute \"%s\" of relation \"%s\"",
153 : attname, RelationGetRelationName(newrelation));
154 7762 : new_attno = ((Form_pg_attribute) GETSTRUCT(newtup))->attnum - 1;
155 : Assert(new_attno >= 0 && new_attno < newnatts);
156 7762 : ReleaseSysCache(newtup);
157 :
158 7762 : att = TupleDescAttr(new_tupdesc, new_attno);
159 : }
160 :
161 : /* Found it, check type and collation match */
162 97618 : if (atttypid != att->atttypid || atttypmod != att->atttypmod)
163 2 : ereport(ERROR,
164 : (errcode(ERRCODE_INVALID_COLUMN_DEFINITION),
165 : errmsg("attribute \"%s\" of relation \"%s\" does not match parent's type",
166 : attname, RelationGetRelationName(newrelation))));
167 97616 : if (attcollation != att->attcollation)
168 0 : ereport(ERROR,
169 : (errcode(ERRCODE_INVALID_COLUMN_DEFINITION),
170 : errmsg("attribute \"%s\" of relation \"%s\" does not match parent's collation",
171 : attname, RelationGetRelationName(newrelation))));
172 :
173 97616 : vars = lappend(vars, makeVar(newvarno,
174 97616 : (AttrNumber) (new_attno + 1),
175 : atttypid,
176 : atttypmod,
177 : attcollation,
178 : 0));
179 97616 : pcolnos[new_attno] = old_attno + 1;
180 97616 : new_attno++;
181 : }
182 :
183 39236 : appinfo->translated_vars = vars;
184 39236 : }
185 :
186 : /*
187 : * adjust_appendrel_attrs
188 : * Copy the specified query or expression and translate Vars referring to a
189 : * parent rel to refer to the corresponding child rel instead. We also
190 : * update rtindexes appearing outside Vars, such as resultRelation and
191 : * jointree relids.
192 : *
193 : * Note: this is only applied after conversion of sublinks to subplans,
194 : * so we don't need to cope with recursion into sub-queries.
195 : *
196 : * Note: this is not hugely different from what pullup_replace_vars() does;
197 : * maybe we should try to fold the two routines together.
198 : */
199 : Node *
200 188876 : adjust_appendrel_attrs(PlannerInfo *root, Node *node, int nappinfos,
201 : AppendRelInfo **appinfos)
202 : {
203 : adjust_appendrel_attrs_context context;
204 :
205 188876 : context.root = root;
206 188876 : context.nappinfos = nappinfos;
207 188876 : context.appinfos = appinfos;
208 :
209 : /* If there's nothing to adjust, don't call this function. */
210 : Assert(nappinfos >= 1 && appinfos != NULL);
211 :
212 : /* Should never be translating a Query tree. */
213 : Assert(node == NULL || !IsA(node, Query));
214 :
215 188876 : return adjust_appendrel_attrs_mutator(node, &context);
216 : }
217 :
218 : static Node *
219 788100 : adjust_appendrel_attrs_mutator(Node *node,
220 : adjust_appendrel_attrs_context *context)
221 : {
222 788100 : AppendRelInfo **appinfos = context->appinfos;
223 788100 : int nappinfos = context->nappinfos;
224 : int cnt;
225 :
226 788100 : if (node == NULL)
227 76280 : return NULL;
228 711820 : if (IsA(node, Var))
229 : {
230 329284 : Var *var = (Var *) copyObject(node);
231 329284 : AppendRelInfo *appinfo = NULL;
232 :
233 329284 : if (var->varlevelsup != 0)
234 0 : return (Node *) var; /* no changes needed */
235 :
236 : /*
237 : * You might think we need to adjust var->varnullingrels, but that
238 : * shouldn't need any changes. It will contain outer-join relids,
239 : * while the transformation we are making affects only baserels.
240 : * Below, we just propagate var->varnullingrels into the translated
241 : * Var.
242 : *
243 : * If var->varnullingrels isn't empty, and the translation wouldn't be
244 : * a Var, we have to fail. One could imagine wrapping the translated
245 : * expression in a PlaceHolderVar, but that won't work because this is
246 : * typically used after freezing placeholders. Fortunately, the case
247 : * appears unreachable at the moment. We can see nonempty
248 : * var->varnullingrels here, but only in cases involving partitionwise
249 : * joining, and in such cases the translations will always be Vars.
250 : * (Non-Var translations occur only for appendrels made by flattening
251 : * UNION ALL subqueries.) Should we need to make this work in future,
252 : * a possible fix is to mandate that prepjointree.c create PHVs for
253 : * all non-Var outputs of such subqueries, and then we could look up
254 : * the pre-existing PHV here. Or perhaps just wrap the translations
255 : * that way to begin with?
256 : *
257 : * If var->varreturningtype is not VAR_RETURNING_DEFAULT, then that
258 : * also needs to be copied to the translated Var. That too would fail
259 : * if the translation wasn't a Var, but that should never happen since
260 : * a non-default var->varreturningtype is only used for Vars referring
261 : * to the result relation, which should never be a flattened UNION ALL
262 : * subquery.
263 : */
264 :
265 404890 : for (cnt = 0; cnt < nappinfos; cnt++)
266 : {
267 365196 : if (var->varno == appinfos[cnt]->parent_relid)
268 : {
269 289590 : appinfo = appinfos[cnt];
270 289590 : break;
271 : }
272 : }
273 :
274 329284 : if (appinfo)
275 : {
276 289590 : var->varno = appinfo->child_relid;
277 : /* it's now a generated Var, so drop any syntactic labeling */
278 289590 : var->varnosyn = 0;
279 289590 : var->varattnosyn = 0;
280 289590 : if (var->varattno > 0)
281 : {
282 : Node *newnode;
283 :
284 271752 : if (var->varattno > list_length(appinfo->translated_vars))
285 0 : elog(ERROR, "attribute %d of relation \"%s\" does not exist",
286 : var->varattno, get_rel_name(appinfo->parent_reloid));
287 271752 : newnode = copyObject(list_nth(appinfo->translated_vars,
288 : var->varattno - 1));
289 271752 : if (newnode == NULL)
290 0 : elog(ERROR, "attribute %d of relation \"%s\" does not exist",
291 : var->varattno, get_rel_name(appinfo->parent_reloid));
292 271752 : if (IsA(newnode, Var))
293 : {
294 268040 : ((Var *) newnode)->varreturningtype = var->varreturningtype;
295 268040 : ((Var *) newnode)->varnullingrels = var->varnullingrels;
296 : }
297 : else
298 : {
299 3712 : if (var->varreturningtype != VAR_RETURNING_DEFAULT)
300 0 : elog(ERROR, "failed to apply returningtype to a non-Var");
301 3712 : if (var->varnullingrels != NULL)
302 0 : elog(ERROR, "failed to apply nullingrels to a non-Var");
303 : }
304 271752 : return newnode;
305 : }
306 17838 : else if (var->varattno == 0)
307 : {
308 : /*
309 : * Whole-row Var: if we are dealing with named rowtypes, we
310 : * can use a whole-row Var for the child table plus a coercion
311 : * step to convert the tuple layout to the parent's rowtype.
312 : * Otherwise we have to generate a RowExpr.
313 : */
314 1066 : if (OidIsValid(appinfo->child_reltype))
315 : {
316 : Assert(var->vartype == appinfo->parent_reltype);
317 1010 : if (appinfo->parent_reltype != appinfo->child_reltype)
318 : {
319 830 : ConvertRowtypeExpr *r = makeNode(ConvertRowtypeExpr);
320 :
321 830 : r->arg = (Expr *) var;
322 830 : r->resulttype = appinfo->parent_reltype;
323 830 : r->convertformat = COERCE_IMPLICIT_CAST;
324 830 : r->location = -1;
325 : /* Make sure the Var node has the right type ID, too */
326 830 : var->vartype = appinfo->child_reltype;
327 830 : return (Node *) r;
328 : }
329 : }
330 : else
331 : {
332 : /*
333 : * Build a RowExpr containing the translated variables.
334 : *
335 : * In practice var->vartype will always be RECORDOID here,
336 : * so we need to come up with some suitable column names.
337 : * We use the parent RTE's column names.
338 : *
339 : * Note: we can't get here for inheritance cases, so there
340 : * is no need to worry that translated_vars might contain
341 : * some dummy NULLs.
342 : */
343 : RowExpr *rowexpr;
344 : List *fields;
345 : RangeTblEntry *rte;
346 :
347 56 : rte = rt_fetch(appinfo->parent_relid,
348 : context->root->parse->rtable);
349 56 : fields = copyObject(appinfo->translated_vars);
350 56 : rowexpr = makeNode(RowExpr);
351 56 : rowexpr->args = fields;
352 56 : rowexpr->row_typeid = var->vartype;
353 56 : rowexpr->row_format = COERCE_IMPLICIT_CAST;
354 56 : rowexpr->colnames = copyObject(rte->eref->colnames);
355 56 : rowexpr->location = -1;
356 :
357 56 : if (var->varreturningtype != VAR_RETURNING_DEFAULT)
358 0 : elog(ERROR, "failed to apply returningtype to a non-Var");
359 56 : if (var->varnullingrels != NULL)
360 0 : elog(ERROR, "failed to apply nullingrels to a non-Var");
361 :
362 56 : return (Node *) rowexpr;
363 : }
364 : }
365 : /* system attributes don't need any other translation */
366 : }
367 39694 : else if (var->varno == ROWID_VAR)
368 : {
369 : /*
370 : * If it's a ROWID_VAR placeholder, see if we've reached a leaf
371 : * target rel, for which we can translate the Var to a specific
372 : * instantiation. We should never be asked to translate to a set
373 : * of relids containing more than one leaf target rel, so the
374 : * answer will be unique. If we're still considering non-leaf
375 : * inheritance levels, return the ROWID_VAR Var as-is.
376 : */
377 18590 : Relids leaf_result_relids = context->root->leaf_result_relids;
378 18590 : Index leaf_relid = 0;
379 :
380 37180 : for (cnt = 0; cnt < nappinfos; cnt++)
381 : {
382 18590 : if (bms_is_member(appinfos[cnt]->child_relid,
383 : leaf_result_relids))
384 : {
385 16410 : if (leaf_relid)
386 0 : elog(ERROR, "cannot translate to multiple leaf relids");
387 16410 : leaf_relid = appinfos[cnt]->child_relid;
388 : }
389 : }
390 :
391 18590 : if (leaf_relid)
392 : {
393 : RowIdentityVarInfo *ridinfo = (RowIdentityVarInfo *)
394 16410 : list_nth(context->root->row_identity_vars, var->varattno - 1);
395 :
396 16410 : if (bms_is_member(leaf_relid, ridinfo->rowidrels))
397 : {
398 : /* Substitute the Var given in the RowIdentityVarInfo */
399 16322 : var = copyObject(ridinfo->rowidvar);
400 : /* ... but use the correct relid */
401 16322 : var->varno = leaf_relid;
402 : /* identity vars shouldn't have nulling rels */
403 : Assert(var->varnullingrels == NULL);
404 : /* varnosyn in the RowIdentityVarInfo is probably wrong */
405 16322 : var->varnosyn = 0;
406 16322 : var->varattnosyn = 0;
407 : }
408 : else
409 : {
410 : /*
411 : * This leaf rel can't return the desired value, so
412 : * substitute a NULL of the correct type.
413 : */
414 88 : return (Node *) makeNullConst(var->vartype,
415 : var->vartypmod,
416 : var->varcollid);
417 : }
418 : }
419 : }
420 56558 : return (Node *) var;
421 : }
422 382536 : if (IsA(node, CurrentOfExpr))
423 : {
424 184 : CurrentOfExpr *cexpr = (CurrentOfExpr *) copyObject(node);
425 :
426 184 : for (cnt = 0; cnt < nappinfos; cnt++)
427 : {
428 184 : AppendRelInfo *appinfo = appinfos[cnt];
429 :
430 184 : if (cexpr->cvarno == appinfo->parent_relid)
431 : {
432 184 : cexpr->cvarno = appinfo->child_relid;
433 184 : break;
434 : }
435 : }
436 184 : return (Node *) cexpr;
437 : }
438 382352 : if (IsA(node, PlaceHolderVar))
439 : {
440 : /* Copy the PlaceHolderVar node with correct mutation of subnodes */
441 : PlaceHolderVar *phv;
442 :
443 2808 : phv = (PlaceHolderVar *) expression_tree_mutator(node,
444 : adjust_appendrel_attrs_mutator,
445 : context);
446 : /* now fix PlaceHolderVar's relid sets */
447 2808 : if (phv->phlevelsup == 0)
448 : {
449 2808 : phv->phrels = adjust_child_relids(phv->phrels,
450 : nappinfos, appinfos);
451 : /* as above, we needn't touch phnullingrels */
452 : }
453 2808 : return (Node *) phv;
454 : }
455 : /* Shouldn't need to handle planner auxiliary nodes here */
456 : Assert(!IsA(node, SpecialJoinInfo));
457 : Assert(!IsA(node, AppendRelInfo));
458 : Assert(!IsA(node, PlaceHolderInfo));
459 : Assert(!IsA(node, MinMaxAggInfo));
460 :
461 : /*
462 : * We have to process RestrictInfo nodes specially. (Note: although
463 : * set_append_rel_pathlist will hide RestrictInfos in the parent's
464 : * baserestrictinfo list from us, it doesn't hide those in joininfo.)
465 : */
466 379544 : if (IsA(node, RestrictInfo))
467 : {
468 24740 : RestrictInfo *oldinfo = (RestrictInfo *) node;
469 24740 : RestrictInfo *newinfo = makeNode(RestrictInfo);
470 :
471 : /* Copy all flat-copiable fields, notably including rinfo_serial */
472 24740 : memcpy(newinfo, oldinfo, sizeof(RestrictInfo));
473 :
474 : /* Recursively fix the clause itself */
475 24740 : newinfo->clause = (Expr *)
476 24740 : adjust_appendrel_attrs_mutator((Node *) oldinfo->clause, context);
477 :
478 : /* and the modified version, if an OR clause */
479 24740 : newinfo->orclause = (Expr *)
480 24740 : adjust_appendrel_attrs_mutator((Node *) oldinfo->orclause, context);
481 :
482 : /* adjust relid sets too */
483 24740 : newinfo->clause_relids = adjust_child_relids(oldinfo->clause_relids,
484 : context->nappinfos,
485 : context->appinfos);
486 24740 : newinfo->required_relids = adjust_child_relids(oldinfo->required_relids,
487 : context->nappinfos,
488 : context->appinfos);
489 24740 : newinfo->outer_relids = adjust_child_relids(oldinfo->outer_relids,
490 : context->nappinfos,
491 : context->appinfos);
492 24740 : newinfo->left_relids = adjust_child_relids(oldinfo->left_relids,
493 : context->nappinfos,
494 : context->appinfos);
495 24740 : newinfo->right_relids = adjust_child_relids(oldinfo->right_relids,
496 : context->nappinfos,
497 : context->appinfos);
498 :
499 : /*
500 : * Reset cached derivative fields, since these might need to have
501 : * different values when considering the child relation. Note we
502 : * don't reset left_ec/right_ec: each child variable is implicitly
503 : * equivalent to its parent, so still a member of the same EC if any.
504 : */
505 24740 : newinfo->eval_cost.startup = -1;
506 24740 : newinfo->norm_selec = -1;
507 24740 : newinfo->outer_selec = -1;
508 24740 : newinfo->left_em = NULL;
509 24740 : newinfo->right_em = NULL;
510 24740 : newinfo->scansel_cache = NIL;
511 24740 : newinfo->left_bucketsize = -1;
512 24740 : newinfo->right_bucketsize = -1;
513 24740 : newinfo->left_mcvfreq = -1;
514 24740 : newinfo->right_mcvfreq = -1;
515 :
516 24740 : return (Node *) newinfo;
517 : }
518 :
519 : /*
520 : * NOTE: we do not need to recurse into sublinks, because they should
521 : * already have been converted to subplans before we see them.
522 : */
523 : Assert(!IsA(node, SubLink));
524 : Assert(!IsA(node, Query));
525 : /* We should never see these Query substructures, either. */
526 : Assert(!IsA(node, RangeTblRef));
527 : Assert(!IsA(node, JoinExpr));
528 :
529 354804 : return expression_tree_mutator(node, adjust_appendrel_attrs_mutator, context);
530 : }
531 :
532 : /*
533 : * adjust_appendrel_attrs_multilevel
534 : * Apply Var translations from an appendrel parent down to a child.
535 : *
536 : * Replace Vars in the "node" expression that reference "parentrel" with
537 : * the appropriate Vars for "childrel". childrel can be more than one
538 : * inheritance level removed from parentrel.
539 : */
540 : Node *
541 25944 : adjust_appendrel_attrs_multilevel(PlannerInfo *root, Node *node,
542 : RelOptInfo *childrel,
543 : RelOptInfo *parentrel)
544 : {
545 : AppendRelInfo **appinfos;
546 : int nappinfos;
547 :
548 : /* Recurse if immediate parent is not the top parent. */
549 25944 : if (childrel->parent != parentrel)
550 : {
551 10252 : if (childrel->parent)
552 10252 : node = adjust_appendrel_attrs_multilevel(root, node,
553 10252 : childrel->parent,
554 : parentrel);
555 : else
556 0 : elog(ERROR, "childrel is not a child of parentrel");
557 : }
558 :
559 : /* Now translate for this child. */
560 25944 : appinfos = find_appinfos_by_relids(root, childrel->relids, &nappinfos);
561 :
562 25944 : node = adjust_appendrel_attrs(root, node, nappinfos, appinfos);
563 :
564 25944 : pfree(appinfos);
565 :
566 25944 : return node;
567 : }
568 :
569 : /*
570 : * Substitute child relids for parent relids in a Relid set. The array of
571 : * appinfos specifies the substitutions to be performed.
572 : */
573 : Relids
574 144530 : adjust_child_relids(Relids relids, int nappinfos, AppendRelInfo **appinfos)
575 : {
576 144530 : Bitmapset *result = NULL;
577 : int cnt;
578 :
579 366232 : for (cnt = 0; cnt < nappinfos; cnt++)
580 : {
581 221702 : AppendRelInfo *appinfo = appinfos[cnt];
582 :
583 : /* Remove parent, add child */
584 221702 : if (bms_is_member(appinfo->parent_relid, relids))
585 : {
586 : /* Make a copy if we are changing the set. */
587 140038 : if (!result)
588 109924 : result = bms_copy(relids);
589 :
590 140038 : result = bms_del_member(result, appinfo->parent_relid);
591 140038 : result = bms_add_member(result, appinfo->child_relid);
592 : }
593 : }
594 :
595 : /* If we made any changes, return the modified copy. */
596 144530 : if (result)
597 109924 : return result;
598 :
599 : /* Otherwise, return the original set without modification. */
600 34606 : return relids;
601 : }
602 :
603 : /*
604 : * Substitute child's relids for parent's relids in a Relid set.
605 : * The childrel can be multiple inheritance levels below the parent.
606 : */
607 : Relids
608 1032 : adjust_child_relids_multilevel(PlannerInfo *root, Relids relids,
609 : RelOptInfo *childrel,
610 : RelOptInfo *parentrel)
611 : {
612 : AppendRelInfo **appinfos;
613 : int nappinfos;
614 :
615 : /*
616 : * If the given relids set doesn't contain any of the parent relids, it
617 : * will remain unchanged.
618 : */
619 1032 : if (!bms_overlap(relids, parentrel->relids))
620 0 : return relids;
621 :
622 : /* Recurse if immediate parent is not the top parent. */
623 1032 : if (childrel->parent != parentrel)
624 : {
625 144 : if (childrel->parent)
626 144 : relids = adjust_child_relids_multilevel(root, relids,
627 144 : childrel->parent,
628 : parentrel);
629 : else
630 0 : elog(ERROR, "childrel is not a child of parentrel");
631 : }
632 :
633 : /* Now translate for this child. */
634 1032 : appinfos = find_appinfos_by_relids(root, childrel->relids, &nappinfos);
635 :
636 1032 : relids = adjust_child_relids(relids, nappinfos, appinfos);
637 :
638 1032 : pfree(appinfos);
639 :
640 1032 : return relids;
641 : }
642 :
643 : /*
644 : * adjust_inherited_attnums
645 : * Translate an integer list of attribute numbers from parent to child.
646 : */
647 : List *
648 5004 : adjust_inherited_attnums(List *attnums, AppendRelInfo *context)
649 : {
650 5004 : List *result = NIL;
651 : ListCell *lc;
652 :
653 : /* This should only happen for an inheritance case, not UNION ALL */
654 : Assert(OidIsValid(context->parent_reloid));
655 :
656 : /* Look up each attribute in the AppendRelInfo's translated_vars list */
657 11142 : foreach(lc, attnums)
658 : {
659 6138 : AttrNumber parentattno = lfirst_int(lc);
660 : Var *childvar;
661 :
662 : /* Look up the translation of this column: it must be a Var */
663 12276 : if (parentattno <= 0 ||
664 6138 : parentattno > list_length(context->translated_vars))
665 0 : elog(ERROR, "attribute %d of relation \"%s\" does not exist",
666 : parentattno, get_rel_name(context->parent_reloid));
667 6138 : childvar = (Var *) list_nth(context->translated_vars, parentattno - 1);
668 6138 : if (childvar == NULL || !IsA(childvar, Var))
669 0 : elog(ERROR, "attribute %d of relation \"%s\" does not exist",
670 : parentattno, get_rel_name(context->parent_reloid));
671 :
672 6138 : result = lappend_int(result, childvar->varattno);
673 : }
674 5004 : return result;
675 : }
676 :
677 : /*
678 : * adjust_inherited_attnums_multilevel
679 : * As above, but traverse multiple inheritance levels as needed.
680 : */
681 : List *
682 5004 : adjust_inherited_attnums_multilevel(PlannerInfo *root, List *attnums,
683 : Index child_relid, Index top_parent_relid)
684 : {
685 5004 : AppendRelInfo *appinfo = root->append_rel_array[child_relid];
686 :
687 5004 : if (!appinfo)
688 0 : elog(ERROR, "child rel %d not found in append_rel_array", child_relid);
689 :
690 : /* Recurse if immediate parent is not the top parent. */
691 5004 : if (appinfo->parent_relid != top_parent_relid)
692 808 : attnums = adjust_inherited_attnums_multilevel(root, attnums,
693 : appinfo->parent_relid,
694 : top_parent_relid);
695 :
696 : /* Now translate for this child */
697 5004 : return adjust_inherited_attnums(attnums, appinfo);
698 : }
699 :
700 : /*
701 : * get_translated_update_targetlist
702 : * Get the processed_tlist of an UPDATE query, translated as needed to
703 : * match a child target relation.
704 : *
705 : * Optionally also return the list of target column numbers translated
706 : * to this target relation. (The resnos in processed_tlist MUST NOT be
707 : * relied on for this purpose.)
708 : */
709 : void
710 100 : get_translated_update_targetlist(PlannerInfo *root, Index relid,
711 : List **processed_tlist, List **update_colnos)
712 : {
713 : /* This is pretty meaningless for commands other than UPDATE. */
714 : Assert(root->parse->commandType == CMD_UPDATE);
715 100 : if (relid == root->parse->resultRelation)
716 : {
717 : /*
718 : * Non-inheritance case, so it's easy. The caller might be expecting
719 : * a tree it can scribble on, though, so copy.
720 : */
721 66 : *processed_tlist = copyObject(root->processed_tlist);
722 66 : if (update_colnos)
723 66 : *update_colnos = copyObject(root->update_colnos);
724 : }
725 : else
726 : {
727 : Assert(bms_is_member(relid, root->all_result_relids));
728 34 : *processed_tlist = (List *)
729 34 : adjust_appendrel_attrs_multilevel(root,
730 34 : (Node *) root->processed_tlist,
731 : find_base_rel(root, relid),
732 34 : find_base_rel(root, root->parse->resultRelation));
733 34 : if (update_colnos)
734 34 : *update_colnos =
735 34 : adjust_inherited_attnums_multilevel(root, root->update_colnos,
736 : relid,
737 34 : root->parse->resultRelation);
738 : }
739 100 : }
740 :
741 : /*
742 : * find_appinfos_by_relids
743 : * Find AppendRelInfo structures for base relations listed in relids.
744 : *
745 : * The relids argument is typically a join relation's relids, which can
746 : * include outer-join RT indexes in addition to baserels. We silently
747 : * ignore the outer joins.
748 : *
749 : * The AppendRelInfos are returned in an array, which can be pfree'd by the
750 : * caller. *nappinfos is set to the number of entries in the array.
751 : */
752 : AppendRelInfo **
753 62380 : find_appinfos_by_relids(PlannerInfo *root, Relids relids, int *nappinfos)
754 : {
755 : AppendRelInfo **appinfos;
756 62380 : int cnt = 0;
757 : int i;
758 :
759 : /* Allocate an array that's certainly big enough */
760 : appinfos = (AppendRelInfo **)
761 62380 : palloc(sizeof(AppendRelInfo *) * bms_num_members(relids));
762 :
763 62380 : i = -1;
764 140962 : while ((i = bms_next_member(relids, i)) >= 0)
765 : {
766 78582 : AppendRelInfo *appinfo = root->append_rel_array[i];
767 :
768 78582 : if (!appinfo)
769 : {
770 : /* Probably i is an OJ index, but let's check */
771 3564 : if (find_base_rel_ignore_join(root, i) == NULL)
772 3564 : continue;
773 : /* It's a base rel, but we lack an append_rel_array entry */
774 0 : elog(ERROR, "child rel %d not found in append_rel_array", i);
775 : }
776 :
777 75018 : appinfos[cnt++] = appinfo;
778 : }
779 62380 : *nappinfos = cnt;
780 62380 : return appinfos;
781 : }
782 :
783 :
784 : /*****************************************************************************
785 : *
786 : * ROW-IDENTITY VARIABLE MANAGEMENT
787 : *
788 : * This code lacks a good home, perhaps. We choose to keep it here because
789 : * adjust_appendrel_attrs_mutator() is its principal co-conspirator. That
790 : * function does most of what is needed to expand ROWID_VAR Vars into the
791 : * right things.
792 : *
793 : *****************************************************************************/
794 :
795 : /*
796 : * add_row_identity_var
797 : * Register a row-identity column to be used in UPDATE/DELETE/MERGE.
798 : *
799 : * The Var must be equal(), aside from varno, to any other row-identity
800 : * column with the same rowid_name. Thus, for example, "wholerow"
801 : * row identities had better use vartype == RECORDOID.
802 : *
803 : * rtindex is currently redundant with rowid_var->varno, but we specify
804 : * it as a separate parameter in case this is ever generalized to support
805 : * non-Var expressions. (We could reasonably handle expressions over
806 : * Vars of the specified rtindex, but for now that seems unnecessary.)
807 : */
808 : void
809 26920 : add_row_identity_var(PlannerInfo *root, Var *orig_var,
810 : Index rtindex, const char *rowid_name)
811 : {
812 : TargetEntry *tle;
813 : Var *rowid_var;
814 : RowIdentityVarInfo *ridinfo;
815 : ListCell *lc;
816 :
817 : /* For now, the argument must be just a Var of the given rtindex */
818 : Assert(IsA(orig_var, Var));
819 : Assert(orig_var->varno == rtindex);
820 : Assert(orig_var->varlevelsup == 0);
821 : Assert(orig_var->varnullingrels == NULL);
822 :
823 : /*
824 : * If we're doing non-inherited UPDATE/DELETE/MERGE, there's little need
825 : * for ROWID_VAR shenanigans. Just shove the presented Var into the
826 : * processed_tlist, and we're done.
827 : */
828 26920 : if (rtindex == root->parse->resultRelation)
829 : {
830 16582 : tle = makeTargetEntry((Expr *) orig_var,
831 16582 : list_length(root->processed_tlist) + 1,
832 : pstrdup(rowid_name),
833 : true);
834 16582 : root->processed_tlist = lappend(root->processed_tlist, tle);
835 16582 : return;
836 : }
837 :
838 : /*
839 : * Otherwise, rtindex should reference a leaf target relation that's being
840 : * added to the query during expand_inherited_rtentry().
841 : */
842 : Assert(bms_is_member(rtindex, root->leaf_result_relids));
843 : Assert(root->append_rel_array[rtindex] != NULL);
844 :
845 : /*
846 : * We have to find a matching RowIdentityVarInfo, or make one if there is
847 : * none. To allow using equal() to match the vars, change the varno to
848 : * ROWID_VAR, leaving all else alone.
849 : */
850 10338 : rowid_var = copyObject(orig_var);
851 : /* This could eventually become ChangeVarNodes() */
852 10338 : rowid_var->varno = ROWID_VAR;
853 :
854 : /* Look for an existing row-id column of the same name */
855 15622 : foreach(lc, root->row_identity_vars)
856 : {
857 10120 : ridinfo = (RowIdentityVarInfo *) lfirst(lc);
858 10120 : if (strcmp(rowid_name, ridinfo->rowidname) != 0)
859 5284 : continue;
860 4836 : if (equal(rowid_var, ridinfo->rowidvar))
861 : {
862 : /* Found a match; we need only record that rtindex needs it too */
863 4836 : ridinfo->rowidrels = bms_add_member(ridinfo->rowidrels, rtindex);
864 4836 : return;
865 : }
866 : else
867 : {
868 : /* Ooops, can't handle this */
869 0 : elog(ERROR, "conflicting uses of row-identity name \"%s\"",
870 : rowid_name);
871 : }
872 : }
873 :
874 : /* No request yet, so add a new RowIdentityVarInfo */
875 5502 : ridinfo = makeNode(RowIdentityVarInfo);
876 5502 : ridinfo->rowidvar = copyObject(rowid_var);
877 : /* for the moment, estimate width using just the datatype info */
878 5502 : ridinfo->rowidwidth = get_typavgwidth(exprType((Node *) rowid_var),
879 : exprTypmod((Node *) rowid_var));
880 5502 : ridinfo->rowidname = pstrdup(rowid_name);
881 5502 : ridinfo->rowidrels = bms_make_singleton(rtindex);
882 :
883 5502 : root->row_identity_vars = lappend(root->row_identity_vars, ridinfo);
884 :
885 : /* Change rowid_var into a reference to this row_identity_vars entry */
886 5502 : rowid_var->varattno = list_length(root->row_identity_vars);
887 :
888 : /* Push the ROWID_VAR reference variable into processed_tlist */
889 5502 : tle = makeTargetEntry((Expr *) rowid_var,
890 5502 : list_length(root->processed_tlist) + 1,
891 : pstrdup(rowid_name),
892 : true);
893 5502 : root->processed_tlist = lappend(root->processed_tlist, tle);
894 : }
895 :
896 : /*
897 : * add_row_identity_columns
898 : *
899 : * This function adds the row identity columns needed by the core code.
900 : * FDWs might call add_row_identity_var() for themselves to add nonstandard
901 : * columns. (Duplicate requests are fine.)
902 : */
903 : void
904 21868 : add_row_identity_columns(PlannerInfo *root, Index rtindex,
905 : RangeTblEntry *target_rte,
906 : Relation target_relation)
907 : {
908 21868 : CmdType commandType = root->parse->commandType;
909 21868 : char relkind = target_relation->rd_rel->relkind;
910 : Var *var;
911 :
912 : Assert(commandType == CMD_UPDATE || commandType == CMD_DELETE || commandType == CMD_MERGE);
913 :
914 21868 : if (relkind == RELKIND_RELATION ||
915 700 : relkind == RELKIND_MATVIEW ||
916 : relkind == RELKIND_PARTITIONED_TABLE)
917 : {
918 : /*
919 : * Emit CTID so that executor can find the row to merge, update or
920 : * delete.
921 : */
922 21204 : var = makeVar(rtindex,
923 : SelfItemPointerAttributeNumber,
924 : TIDOID,
925 : -1,
926 : InvalidOid,
927 : 0);
928 21204 : add_row_identity_var(root, var, rtindex, "ctid");
929 : }
930 664 : else if (relkind == RELKIND_FOREIGN_TABLE)
931 : {
932 : /*
933 : * Let the foreign table's FDW add whatever junk TLEs it wants.
934 : */
935 : FdwRoutine *fdwroutine;
936 :
937 370 : fdwroutine = GetFdwRoutineForRelation(target_relation, false);
938 :
939 370 : if (fdwroutine->AddForeignUpdateTargets != NULL)
940 362 : fdwroutine->AddForeignUpdateTargets(root, rtindex,
941 : target_rte, target_relation);
942 :
943 : /*
944 : * For UPDATE, we need to make the FDW fetch unchanged columns by
945 : * asking it to fetch a whole-row Var. That's because the top-level
946 : * targetlist only contains entries for changed columns, but
947 : * ExecUpdate will need to build the complete new tuple. (Actually,
948 : * we only really need this in UPDATEs that are not pushed to the
949 : * remote side, but it's hard to tell if that will be the case at the
950 : * point when this function is called.)
951 : *
952 : * We will also need the whole row if there are any row triggers, so
953 : * that the executor will have the "old" row to pass to the trigger.
954 : * Alas, this misses system columns.
955 : */
956 370 : if (commandType == CMD_UPDATE ||
957 164 : (target_relation->trigdesc &&
958 30 : (target_relation->trigdesc->trig_delete_after_row ||
959 18 : target_relation->trigdesc->trig_delete_before_row)))
960 : {
961 222 : var = makeVar(rtindex,
962 : InvalidAttrNumber,
963 : RECORDOID,
964 : -1,
965 : InvalidOid,
966 : 0);
967 222 : add_row_identity_var(root, var, rtindex, "wholerow");
968 : }
969 : }
970 21868 : }
971 :
972 : /*
973 : * distribute_row_identity_vars
974 : *
975 : * After we have finished identifying all the row identity columns
976 : * needed by an inherited UPDATE/DELETE/MERGE query, make sure that
977 : * these columns will be generated by all the target relations.
978 : *
979 : * This is more or less like what build_base_rel_tlists() does,
980 : * except that it would not understand what to do with ROWID_VAR Vars.
981 : * Since that function runs before inheritance relations are expanded,
982 : * it will never see any such Vars anyway.
983 : */
984 : void
985 290720 : distribute_row_identity_vars(PlannerInfo *root)
986 : {
987 290720 : Query *parse = root->parse;
988 290720 : int result_relation = parse->resultRelation;
989 : RangeTblEntry *target_rte;
990 : RelOptInfo *target_rel;
991 : ListCell *lc;
992 :
993 : /*
994 : * There's nothing to do if this isn't an inherited UPDATE/DELETE/MERGE.
995 : */
996 290720 : if (parse->commandType != CMD_UPDATE && parse->commandType != CMD_DELETE &&
997 273030 : parse->commandType != CMD_MERGE)
998 : {
999 : Assert(root->row_identity_vars == NIL);
1000 271278 : return;
1001 : }
1002 19442 : target_rte = rt_fetch(result_relation, parse->rtable);
1003 19442 : if (!target_rte->inh)
1004 : {
1005 : Assert(root->row_identity_vars == NIL);
1006 16698 : return;
1007 : }
1008 :
1009 : /*
1010 : * Ordinarily, we expect that leaf result relation(s) will have added some
1011 : * ROWID_VAR Vars to the query. However, it's possible that constraint
1012 : * exclusion suppressed every leaf relation. The executor will get upset
1013 : * if the plan has no row identity columns at all, even though it will
1014 : * certainly process no rows. Handle this edge case by re-opening the top
1015 : * result relation and adding the row identity columns it would have used,
1016 : * as preprocess_targetlist() would have done if it weren't marked "inh".
1017 : * Then re-run build_base_rel_tlists() to ensure that the added columns
1018 : * get propagated to the relation's reltarget. (This is a bit ugly, but
1019 : * it seems better to confine the ugliness and extra cycles to this
1020 : * unusual corner case.)
1021 : */
1022 2744 : if (root->row_identity_vars == NIL)
1023 : {
1024 : Relation target_relation;
1025 :
1026 30 : target_relation = table_open(target_rte->relid, NoLock);
1027 30 : add_row_identity_columns(root, result_relation,
1028 : target_rte, target_relation);
1029 30 : table_close(target_relation, NoLock);
1030 30 : build_base_rel_tlists(root, root->processed_tlist);
1031 : /* There are no ROWID_VAR Vars in this case, so we're done. */
1032 30 : return;
1033 : }
1034 :
1035 : /*
1036 : * Dig through the processed_tlist to find the ROWID_VAR reference Vars,
1037 : * and forcibly copy them into the reltarget list of the topmost target
1038 : * relation. That's sufficient because they'll be copied to the
1039 : * individual leaf target rels (with appropriate translation) later,
1040 : * during appendrel expansion --- see set_append_rel_size().
1041 : */
1042 2714 : target_rel = find_base_rel(root, result_relation);
1043 :
1044 11446 : foreach(lc, root->processed_tlist)
1045 : {
1046 8732 : TargetEntry *tle = lfirst(lc);
1047 8732 : Var *var = (Var *) tle->expr;
1048 :
1049 8732 : if (var && IsA(var, Var) && var->varno == ROWID_VAR)
1050 : {
1051 5502 : target_rel->reltarget->exprs =
1052 5502 : lappend(target_rel->reltarget->exprs, copyObject(var));
1053 : /* reltarget cost and width will be computed later */
1054 : }
1055 : }
1056 : }
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