Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * appendinfo.c
4 : * Routines for mapping between append parent(s) and children
5 : *
6 : * Portions Copyright (c) 1996-2026, 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/sysattr.h"
19 : #include "access/table.h"
20 : #include "foreign/fdwapi.h"
21 : #include "nodes/makefuncs.h"
22 : #include "nodes/nodeFuncs.h"
23 : #include "optimizer/appendinfo.h"
24 : #include "optimizer/pathnode.h"
25 : #include "optimizer/planmain.h"
26 : #include "parser/parsetree.h"
27 : #include "utils/lsyscache.h"
28 : #include "utils/rel.h"
29 : #include "utils/syscache.h"
30 :
31 :
32 : typedef struct
33 : {
34 : PlannerInfo *root;
35 : int nappinfos;
36 : AppendRelInfo **appinfos;
37 : } adjust_appendrel_attrs_context;
38 :
39 : static void make_inh_translation_list(Relation oldrelation,
40 : Relation newrelation,
41 : Index newvarno,
42 : AppendRelInfo *appinfo);
43 : static Node *adjust_appendrel_attrs_mutator(Node *node,
44 : adjust_appendrel_attrs_context *context);
45 :
46 :
47 : /*
48 : * make_append_rel_info
49 : * Build an AppendRelInfo for the parent-child pair
50 : */
51 : AppendRelInfo *
52 34879 : make_append_rel_info(Relation parentrel, Relation childrel,
53 : Index parentRTindex, Index childRTindex)
54 : {
55 34879 : AppendRelInfo *appinfo = makeNode(AppendRelInfo);
56 :
57 34879 : appinfo->parent_relid = parentRTindex;
58 34879 : appinfo->child_relid = childRTindex;
59 34879 : appinfo->parent_reltype = parentrel->rd_rel->reltype;
60 34879 : appinfo->child_reltype = childrel->rd_rel->reltype;
61 34879 : make_inh_translation_list(parentrel, childrel, childRTindex, appinfo);
62 34878 : appinfo->parent_reloid = RelationGetRelid(parentrel);
63 :
64 34878 : return appinfo;
65 : }
66 :
67 : /*
68 : * make_inh_translation_list
69 : * Build the list of translations from parent Vars to child Vars for
70 : * an inheritance child, as well as a reverse-translation array.
71 : *
72 : * The reverse-translation array has an entry for each child relation
73 : * column, which is either the 1-based index of the corresponding parent
74 : * column, or 0 if there's no match (that happens for dropped child columns,
75 : * as well as child columns beyond those of the parent, which are allowed in
76 : * traditional inheritance though not partitioning).
77 : *
78 : * For paranoia's sake, we match type/collation as well as attribute name.
79 : */
80 : static void
81 34879 : make_inh_translation_list(Relation oldrelation, Relation newrelation,
82 : Index newvarno,
83 : AppendRelInfo *appinfo)
84 : {
85 34879 : List *vars = NIL;
86 : AttrNumber *pcolnos;
87 34879 : TupleDesc old_tupdesc = RelationGetDescr(oldrelation);
88 34879 : TupleDesc new_tupdesc = RelationGetDescr(newrelation);
89 34879 : Oid new_relid = RelationGetRelid(newrelation);
90 34879 : int oldnatts = old_tupdesc->natts;
91 34879 : int newnatts = new_tupdesc->natts;
92 : int old_attno;
93 34879 : int new_attno = 0;
94 :
95 : /* Initialize reverse-translation array with all entries zero */
96 34879 : appinfo->num_child_cols = newnatts;
97 34879 : appinfo->parent_colnos = pcolnos =
98 34879 : (AttrNumber *) palloc0(newnatts * sizeof(AttrNumber));
99 :
100 128906 : for (old_attno = 0; old_attno < oldnatts; old_attno++)
101 : {
102 : Form_pg_attribute att;
103 : char *attname;
104 : Oid atttypid;
105 : int32 atttypmod;
106 : Oid attcollation;
107 :
108 94028 : att = TupleDescAttr(old_tupdesc, old_attno);
109 94028 : if (att->attisdropped)
110 : {
111 : /* Just put NULL into this list entry */
112 2643 : vars = lappend(vars, NULL);
113 2643 : continue;
114 : }
115 91385 : attname = NameStr(att->attname);
116 91385 : atttypid = att->atttypid;
117 91385 : atttypmod = att->atttypmod;
118 91385 : attcollation = att->attcollation;
119 :
120 : /*
121 : * When we are generating the "translation list" for the parent table
122 : * of an inheritance set, no need to search for matches.
123 : */
124 91385 : if (oldrelation == newrelation)
125 : {
126 5789 : vars = lappend(vars, makeVar(newvarno,
127 5789 : (AttrNumber) (old_attno + 1),
128 : atttypid,
129 : atttypmod,
130 : attcollation,
131 : 0));
132 5789 : pcolnos[old_attno] = old_attno + 1;
133 5789 : continue;
134 : }
135 :
136 : /*
137 : * Otherwise we have to search for the matching column by name.
138 : * There's no guarantee it'll have the same column position, because
139 : * of cases like ALTER TABLE ADD COLUMN and multiple inheritance.
140 : * However, in simple cases, the relative order of columns is mostly
141 : * the same in both relations, so try the column of newrelation that
142 : * follows immediately after the one that we just found, and if that
143 : * fails, let syscache handle it.
144 : */
145 85596 : if (new_attno >= newnatts ||
146 83760 : (att = TupleDescAttr(new_tupdesc, new_attno))->attisdropped ||
147 82980 : strcmp(attname, NameStr(att->attname)) != 0)
148 : {
149 : HeapTuple newtup;
150 :
151 6887 : newtup = SearchSysCacheAttName(new_relid, attname);
152 6887 : if (!HeapTupleIsValid(newtup))
153 0 : elog(ERROR, "could not find inherited attribute \"%s\" of relation \"%s\"",
154 : attname, RelationGetRelationName(newrelation));
155 6887 : new_attno = ((Form_pg_attribute) GETSTRUCT(newtup))->attnum - 1;
156 : Assert(new_attno >= 0 && new_attno < newnatts);
157 6887 : ReleaseSysCache(newtup);
158 :
159 6887 : att = TupleDescAttr(new_tupdesc, new_attno);
160 : }
161 :
162 : /* Found it, check type and collation match */
163 85596 : if (atttypid != att->atttypid || atttypmod != att->atttypmod)
164 1 : ereport(ERROR,
165 : (errcode(ERRCODE_INVALID_COLUMN_DEFINITION),
166 : errmsg("attribute \"%s\" of relation \"%s\" does not match parent's type",
167 : attname, RelationGetRelationName(newrelation))));
168 85595 : if (attcollation != att->attcollation)
169 0 : ereport(ERROR,
170 : (errcode(ERRCODE_INVALID_COLUMN_DEFINITION),
171 : errmsg("attribute \"%s\" of relation \"%s\" does not match parent's collation",
172 : attname, RelationGetRelationName(newrelation))));
173 :
174 85595 : vars = lappend(vars, makeVar(newvarno,
175 85595 : (AttrNumber) (new_attno + 1),
176 : atttypid,
177 : atttypmod,
178 : attcollation,
179 : 0));
180 85595 : pcolnos[new_attno] = old_attno + 1;
181 85595 : new_attno++;
182 : }
183 :
184 34878 : appinfo->translated_vars = vars;
185 34878 : }
186 :
187 : /*
188 : * adjust_appendrel_attrs
189 : * Copy the specified query or expression and translate Vars referring to a
190 : * parent rel to refer to the corresponding child rel instead. We also
191 : * update rtindexes appearing outside Vars, such as resultRelation and
192 : * jointree relids.
193 : *
194 : * Note: this is only applied after conversion of sublinks to subplans,
195 : * so we don't need to cope with recursion into sub-queries.
196 : *
197 : * Note: this is not hugely different from what pullup_replace_vars() does;
198 : * maybe we should try to fold the two routines together.
199 : */
200 : Node *
201 243646 : adjust_appendrel_attrs(PlannerInfo *root, Node *node, int nappinfos,
202 : AppendRelInfo **appinfos)
203 : {
204 : adjust_appendrel_attrs_context context;
205 :
206 243646 : context.root = root;
207 243646 : context.nappinfos = nappinfos;
208 243646 : context.appinfos = appinfos;
209 :
210 : /* If there's nothing to adjust, don't call this function. */
211 : Assert(nappinfos >= 1 && appinfos != NULL);
212 :
213 : /* Should never be translating a Query tree. */
214 : Assert(node == NULL || !IsA(node, Query));
215 :
216 243646 : return adjust_appendrel_attrs_mutator(node, &context);
217 : }
218 :
219 : static Node *
220 1273289 : adjust_appendrel_attrs_mutator(Node *node,
221 : adjust_appendrel_attrs_context *context)
222 : {
223 1273289 : AppendRelInfo **appinfos = context->appinfos;
224 1273289 : int nappinfos = context->nappinfos;
225 : int cnt;
226 :
227 1273289 : if (node == NULL)
228 236891 : return NULL;
229 1036398 : if (IsA(node, Var))
230 : {
231 464760 : Var *var = (Var *) copyObject(node);
232 464760 : AppendRelInfo *appinfo = NULL;
233 :
234 464760 : if (var->varlevelsup != 0)
235 0 : return (Node *) var; /* no changes needed */
236 :
237 : /*
238 : * You might think we need to adjust var->varnullingrels, but that
239 : * shouldn't need any changes. It will contain outer-join relids,
240 : * while the transformation we are making affects only baserels.
241 : * Below, we just merge var->varnullingrels into the translated Var.
242 : * (We must merge not just copy: the child Var could have some
243 : * nullingrel bits set already, and we mustn't drop those.)
244 : *
245 : * If var->varnullingrels isn't empty, and the translation wouldn't be
246 : * a Var, we have to fail. One could imagine wrapping the translated
247 : * expression in a PlaceHolderVar, but that won't work because this is
248 : * typically used after freezing placeholders. Fortunately, the case
249 : * appears unreachable at the moment. We can see nonempty
250 : * var->varnullingrels here, but only in cases involving partitionwise
251 : * joining, and in such cases the translations will always be Vars.
252 : * (Non-Var translations occur only for appendrels made by flattening
253 : * UNION ALL subqueries.) Should we need to make this work in future,
254 : * a possible fix is to mandate that prepjointree.c create PHVs for
255 : * all non-Var outputs of such subqueries, and then we could look up
256 : * the pre-existing PHV here. Or perhaps just wrap the translations
257 : * that way to begin with?
258 : *
259 : * If var->varreturningtype is not VAR_RETURNING_DEFAULT, then that
260 : * also needs to be copied to the translated Var. That too would fail
261 : * if the translation wasn't a Var, but that should never happen since
262 : * a non-default var->varreturningtype is only used for Vars referring
263 : * to the result relation, which should never be a flattened UNION ALL
264 : * subquery.
265 : */
266 :
267 580654 : for (cnt = 0; cnt < nappinfos; cnt++)
268 : {
269 546738 : if (var->varno == appinfos[cnt]->parent_relid)
270 : {
271 430844 : appinfo = appinfos[cnt];
272 430844 : break;
273 : }
274 : }
275 :
276 464760 : if (appinfo)
277 : {
278 430844 : var->varno = appinfo->child_relid;
279 : /* it's now a generated Var, so drop any syntactic labeling */
280 430844 : var->varnosyn = 0;
281 430844 : var->varattnosyn = 0;
282 430844 : if (var->varattno > 0)
283 : {
284 : Node *newnode;
285 :
286 414035 : if (var->varattno > list_length(appinfo->translated_vars))
287 0 : elog(ERROR, "attribute %d of relation \"%s\" does not exist",
288 : var->varattno, get_rel_name(appinfo->parent_reloid));
289 414035 : newnode = copyObject(list_nth(appinfo->translated_vars,
290 : var->varattno - 1));
291 414035 : if (newnode == NULL)
292 0 : elog(ERROR, "attribute %d of relation \"%s\" does not exist",
293 : var->varattno, get_rel_name(appinfo->parent_reloid));
294 414035 : if (IsA(newnode, Var))
295 : {
296 406279 : Var *newvar = (Var *) newnode;
297 :
298 406279 : newvar->varreturningtype = var->varreturningtype;
299 406279 : newvar->varnullingrels = bms_add_members(newvar->varnullingrels,
300 406279 : var->varnullingrels);
301 : }
302 : else
303 : {
304 7756 : if (var->varreturningtype != VAR_RETURNING_DEFAULT)
305 0 : elog(ERROR, "failed to apply returningtype to a non-Var");
306 7756 : if (var->varnullingrels != NULL)
307 0 : elog(ERROR, "failed to apply nullingrels to a non-Var");
308 : }
309 414035 : return newnode;
310 : }
311 16809 : else if (var->varattno == 0)
312 : {
313 : /*
314 : * Whole-row Var: if we are dealing with named rowtypes, we
315 : * can use a whole-row Var for the child table plus a coercion
316 : * step to convert the tuple layout to the parent's rowtype.
317 : * Otherwise we have to generate a RowExpr.
318 : */
319 845 : if (OidIsValid(appinfo->child_reltype))
320 : {
321 : Assert(var->vartype == appinfo->parent_reltype);
322 801 : if (appinfo->parent_reltype != appinfo->child_reltype)
323 : {
324 655 : ConvertRowtypeExpr *r = makeNode(ConvertRowtypeExpr);
325 :
326 655 : r->arg = (Expr *) var;
327 655 : r->resulttype = appinfo->parent_reltype;
328 655 : r->convertformat = COERCE_IMPLICIT_CAST;
329 655 : r->location = -1;
330 : /* Make sure the Var node has the right type ID, too */
331 655 : var->vartype = appinfo->child_reltype;
332 655 : return (Node *) r;
333 : }
334 : }
335 : else
336 : {
337 : /*
338 : * Build a RowExpr containing the translated variables.
339 : *
340 : * In practice var->vartype will always be RECORDOID here,
341 : * so we need to come up with some suitable column names.
342 : * We use the parent RTE's column names.
343 : *
344 : * Note: we can't get here for inheritance cases, so there
345 : * is no need to worry that translated_vars might contain
346 : * some dummy NULLs.
347 : */
348 : RowExpr *rowexpr;
349 : List *fields;
350 : RangeTblEntry *rte;
351 :
352 44 : rte = rt_fetch(appinfo->parent_relid,
353 : context->root->parse->rtable);
354 44 : fields = copyObject(appinfo->translated_vars);
355 44 : rowexpr = makeNode(RowExpr);
356 44 : rowexpr->args = fields;
357 44 : rowexpr->row_typeid = var->vartype;
358 44 : rowexpr->row_format = COERCE_IMPLICIT_CAST;
359 44 : rowexpr->colnames = copyObject(rte->eref->colnames);
360 44 : rowexpr->location = -1;
361 :
362 44 : if (var->varreturningtype != VAR_RETURNING_DEFAULT)
363 0 : elog(ERROR, "failed to apply returningtype to a non-Var");
364 44 : if (var->varnullingrels != NULL)
365 0 : elog(ERROR, "failed to apply nullingrels to a non-Var");
366 :
367 44 : return (Node *) rowexpr;
368 : }
369 : }
370 : /* system attributes don't need any other translation */
371 : }
372 33916 : else if (var->varno == ROWID_VAR)
373 : {
374 : /*
375 : * If it's a ROWID_VAR placeholder, see if we've reached a leaf
376 : * target rel, for which we can translate the Var to a specific
377 : * instantiation. We should never be asked to translate to a set
378 : * of relids containing more than one leaf target rel, so the
379 : * answer will be unique. If we're still considering non-leaf
380 : * inheritance levels, return the ROWID_VAR Var as-is.
381 : */
382 15187 : Relids leaf_result_relids = context->root->leaf_result_relids;
383 15187 : Index leaf_relid = 0;
384 :
385 30374 : for (cnt = 0; cnt < nappinfos; cnt++)
386 : {
387 15187 : if (bms_is_member(appinfos[cnt]->child_relid,
388 : leaf_result_relids))
389 : {
390 13321 : if (leaf_relid)
391 0 : elog(ERROR, "cannot translate to multiple leaf relids");
392 13321 : leaf_relid = appinfos[cnt]->child_relid;
393 : }
394 : }
395 :
396 15187 : if (leaf_relid)
397 : {
398 : RowIdentityVarInfo *ridinfo = (RowIdentityVarInfo *)
399 13321 : list_nth(context->root->row_identity_vars, var->varattno - 1);
400 :
401 13321 : if (bms_is_member(leaf_relid, ridinfo->rowidrels))
402 : {
403 : /* Substitute the Var given in the RowIdentityVarInfo */
404 13275 : var = copyObject(ridinfo->rowidvar);
405 : /* ... but use the correct relid */
406 13275 : var->varno = leaf_relid;
407 : /* identity vars shouldn't have nulling rels */
408 : Assert(var->varnullingrels == NULL);
409 : /* varnosyn in the RowIdentityVarInfo is probably wrong */
410 13275 : var->varnosyn = 0;
411 13275 : var->varattnosyn = 0;
412 : }
413 : else
414 : {
415 : /*
416 : * This leaf rel can't return the desired value, so
417 : * substitute a NULL of the correct type.
418 : */
419 46 : return (Node *) makeNullConst(var->vartype,
420 : var->vartypmod,
421 : var->varcollid);
422 : }
423 : }
424 : }
425 49980 : return (Node *) var;
426 : }
427 571638 : if (IsA(node, CurrentOfExpr))
428 : {
429 152 : CurrentOfExpr *cexpr = (CurrentOfExpr *) copyObject(node);
430 :
431 152 : for (cnt = 0; cnt < nappinfos; cnt++)
432 : {
433 152 : AppendRelInfo *appinfo = appinfos[cnt];
434 :
435 152 : if (cexpr->cvarno == appinfo->parent_relid)
436 : {
437 152 : cexpr->cvarno = appinfo->child_relid;
438 152 : break;
439 : }
440 : }
441 152 : return (Node *) cexpr;
442 : }
443 571486 : if (IsA(node, PlaceHolderVar))
444 : {
445 : /* Copy the PlaceHolderVar node with correct mutation of subnodes */
446 : PlaceHolderVar *phv;
447 :
448 2302 : phv = (PlaceHolderVar *) expression_tree_mutator(node,
449 : adjust_appendrel_attrs_mutator,
450 : context);
451 : /* now fix PlaceHolderVar's relid sets */
452 2302 : if (phv->phlevelsup == 0)
453 : {
454 2302 : phv->phrels = adjust_child_relids(phv->phrels,
455 : nappinfos, appinfos);
456 : /* as above, we needn't touch phnullingrels */
457 : }
458 2302 : return (Node *) phv;
459 : }
460 : /* Shouldn't need to handle planner auxiliary nodes here */
461 : Assert(!IsA(node, SpecialJoinInfo));
462 : Assert(!IsA(node, AppendRelInfo));
463 : Assert(!IsA(node, PlaceHolderInfo));
464 : Assert(!IsA(node, MinMaxAggInfo));
465 :
466 : /*
467 : * We have to process RestrictInfo nodes specially. (Note: although
468 : * set_append_rel_pathlist will hide RestrictInfos in the parent's
469 : * baserestrictinfo list from us, it doesn't hide those in joininfo.)
470 : */
471 569184 : if (IsA(node, RestrictInfo))
472 : {
473 33437 : RestrictInfo *oldinfo = (RestrictInfo *) node;
474 33437 : RestrictInfo *newinfo = makeNode(RestrictInfo);
475 :
476 : /* Copy all flat-copiable fields, notably including rinfo_serial */
477 33437 : memcpy(newinfo, oldinfo, sizeof(RestrictInfo));
478 :
479 : /* Recursively fix the clause itself */
480 33437 : newinfo->clause = (Expr *)
481 33437 : adjust_appendrel_attrs_mutator((Node *) oldinfo->clause, context);
482 :
483 : /* and the modified version, if an OR clause */
484 33437 : newinfo->orclause = (Expr *)
485 33437 : adjust_appendrel_attrs_mutator((Node *) oldinfo->orclause, context);
486 :
487 : /* adjust relid sets too */
488 33437 : newinfo->clause_relids = adjust_child_relids(oldinfo->clause_relids,
489 : context->nappinfos,
490 : context->appinfos);
491 33437 : newinfo->required_relids = adjust_child_relids(oldinfo->required_relids,
492 : context->nappinfos,
493 : context->appinfos);
494 33437 : newinfo->outer_relids = adjust_child_relids(oldinfo->outer_relids,
495 : context->nappinfos,
496 : context->appinfos);
497 33437 : newinfo->left_relids = adjust_child_relids(oldinfo->left_relids,
498 : context->nappinfos,
499 : context->appinfos);
500 33437 : newinfo->right_relids = adjust_child_relids(oldinfo->right_relids,
501 : context->nappinfos,
502 : context->appinfos);
503 :
504 : /*
505 : * Reset cached derivative fields, since these might need to have
506 : * different values when considering the child relation. Note we
507 : * don't reset left_ec/right_ec: each child variable is implicitly
508 : * equivalent to its parent, so still a member of the same EC if any.
509 : */
510 33437 : newinfo->eval_cost.startup = -1;
511 33437 : newinfo->norm_selec = -1;
512 33437 : newinfo->outer_selec = -1;
513 33437 : newinfo->left_em = NULL;
514 33437 : newinfo->right_em = NULL;
515 33437 : newinfo->scansel_cache = NIL;
516 33437 : newinfo->left_bucketsize = -1;
517 33437 : newinfo->right_bucketsize = -1;
518 33437 : newinfo->left_mcvfreq = -1;
519 33437 : newinfo->right_mcvfreq = -1;
520 :
521 33437 : return (Node *) newinfo;
522 : }
523 :
524 : /*
525 : * We have to process RelAggInfo nodes specially.
526 : */
527 535747 : if (IsA(node, RelAggInfo))
528 : {
529 15500 : RelAggInfo *oldinfo = (RelAggInfo *) node;
530 15500 : RelAggInfo *newinfo = makeNode(RelAggInfo);
531 :
532 15500 : newinfo->target = (PathTarget *)
533 15500 : adjust_appendrel_attrs_mutator((Node *) oldinfo->target,
534 : context);
535 :
536 15500 : newinfo->agg_input = (PathTarget *)
537 15500 : adjust_appendrel_attrs_mutator((Node *) oldinfo->agg_input,
538 : context);
539 :
540 15500 : newinfo->group_clauses = oldinfo->group_clauses;
541 :
542 15500 : newinfo->group_exprs = (List *)
543 15500 : adjust_appendrel_attrs_mutator((Node *) oldinfo->group_exprs,
544 : context);
545 :
546 15500 : return (Node *) newinfo;
547 : }
548 :
549 : /*
550 : * We have to process PathTarget nodes specially.
551 : */
552 520247 : if (IsA(node, PathTarget))
553 : {
554 31000 : PathTarget *oldtarget = (PathTarget *) node;
555 31000 : PathTarget *newtarget = makeNode(PathTarget);
556 :
557 : /* Copy all flat-copiable fields */
558 31000 : memcpy(newtarget, oldtarget, sizeof(PathTarget));
559 :
560 31000 : newtarget->exprs = (List *)
561 31000 : adjust_appendrel_attrs_mutator((Node *) oldtarget->exprs,
562 : context);
563 :
564 31000 : if (oldtarget->sortgrouprefs)
565 : {
566 31000 : Size nbytes = list_length(oldtarget->exprs) * sizeof(Index);
567 :
568 31000 : newtarget->sortgrouprefs = (Index *) palloc(nbytes);
569 31000 : memcpy(newtarget->sortgrouprefs, oldtarget->sortgrouprefs, nbytes);
570 : }
571 :
572 31000 : return (Node *) newtarget;
573 : }
574 :
575 : /*
576 : * NOTE: we do not need to recurse into sublinks, because they should
577 : * already have been converted to subplans before we see them.
578 : */
579 : Assert(!IsA(node, SubLink));
580 : Assert(!IsA(node, Query));
581 : /* We should never see these Query substructures, either. */
582 : Assert(!IsA(node, RangeTblRef));
583 : Assert(!IsA(node, JoinExpr));
584 :
585 489247 : return expression_tree_mutator(node, adjust_appendrel_attrs_mutator, context);
586 : }
587 :
588 : /*
589 : * adjust_appendrel_attrs_multilevel
590 : * Apply Var translations from an appendrel parent down to a child.
591 : *
592 : * Replace Vars in the "node" expression that reference "parentrel" with
593 : * the appropriate Vars for "childrel". childrel can be more than one
594 : * inheritance level removed from parentrel.
595 : */
596 : Node *
597 39578 : adjust_appendrel_attrs_multilevel(PlannerInfo *root, Node *node,
598 : RelOptInfo *childrel,
599 : RelOptInfo *parentrel)
600 : {
601 : AppendRelInfo **appinfos;
602 : int nappinfos;
603 :
604 : /* Recurse if immediate parent is not the top parent. */
605 39578 : if (childrel->parent != parentrel)
606 : {
607 13619 : if (childrel->parent)
608 13619 : node = adjust_appendrel_attrs_multilevel(root, node,
609 13619 : childrel->parent,
610 : parentrel);
611 : else
612 0 : elog(ERROR, "childrel is not a child of parentrel");
613 : }
614 :
615 : /* Now translate for this child. */
616 39578 : appinfos = find_appinfos_by_relids(root, childrel->relids, &nappinfos);
617 :
618 39578 : node = adjust_appendrel_attrs(root, node, nappinfos, appinfos);
619 :
620 39578 : pfree(appinfos);
621 :
622 39578 : return node;
623 : }
624 :
625 : /*
626 : * Substitute child relids for parent relids in a Relid set. The array of
627 : * appinfos specifies the substitutions to be performed.
628 : */
629 : Relids
630 196413 : adjust_child_relids(Relids relids, int nappinfos, AppendRelInfo **appinfos)
631 : {
632 196413 : Bitmapset *result = NULL;
633 : int cnt;
634 :
635 532366 : for (cnt = 0; cnt < nappinfos; cnt++)
636 : {
637 335953 : AppendRelInfo *appinfo = appinfos[cnt];
638 :
639 : /* Remove parent, add child */
640 335953 : if (bms_is_member(appinfo->parent_relid, relids))
641 : {
642 : /* Make a copy if we are changing the set. */
643 214109 : if (!result)
644 153479 : result = bms_copy(relids);
645 :
646 214109 : result = bms_del_member(result, appinfo->parent_relid);
647 214109 : result = bms_add_member(result, appinfo->child_relid);
648 : }
649 : }
650 :
651 : /* If we made any changes, return the modified copy. */
652 196413 : if (result)
653 153479 : return result;
654 :
655 : /* Otherwise, return the original set without modification. */
656 42934 : return relids;
657 : }
658 :
659 : /*
660 : * Substitute child's relids for parent's relids in a Relid set.
661 : * The childrel can be multiple inheritance levels below the parent.
662 : */
663 : Relids
664 967 : adjust_child_relids_multilevel(PlannerInfo *root, Relids relids,
665 : RelOptInfo *childrel,
666 : RelOptInfo *parentrel)
667 : {
668 : AppendRelInfo **appinfos;
669 : int nappinfos;
670 :
671 : /*
672 : * If the given relids set doesn't contain any of the parent relids, it
673 : * will remain unchanged.
674 : */
675 967 : if (!bms_overlap(relids, parentrel->relids))
676 0 : return relids;
677 :
678 : /* Recurse if immediate parent is not the top parent. */
679 967 : if (childrel->parent != parentrel)
680 : {
681 120 : if (childrel->parent)
682 120 : relids = adjust_child_relids_multilevel(root, relids,
683 120 : childrel->parent,
684 : parentrel);
685 : else
686 0 : elog(ERROR, "childrel is not a child of parentrel");
687 : }
688 :
689 : /* Now translate for this child. */
690 967 : appinfos = find_appinfos_by_relids(root, childrel->relids, &nappinfos);
691 :
692 967 : relids = adjust_child_relids(relids, nappinfos, appinfos);
693 :
694 967 : pfree(appinfos);
695 :
696 967 : return relids;
697 : }
698 :
699 : /*
700 : * adjust_inherited_attnums
701 : * Translate an integer list of attribute numbers from parent to child.
702 : */
703 : List *
704 4038 : adjust_inherited_attnums(List *attnums, AppendRelInfo *context)
705 : {
706 4038 : List *result = NIL;
707 : ListCell *lc;
708 :
709 : /* This should only happen for an inheritance case, not UNION ALL */
710 : Assert(OidIsValid(context->parent_reloid));
711 :
712 : /* Look up each attribute in the AppendRelInfo's translated_vars list */
713 9019 : foreach(lc, attnums)
714 : {
715 4981 : AttrNumber parentattno = lfirst_int(lc);
716 : Var *childvar;
717 :
718 : /* Look up the translation of this column: it must be a Var */
719 9962 : if (parentattno <= 0 ||
720 4981 : parentattno > list_length(context->translated_vars))
721 0 : elog(ERROR, "attribute %d of relation \"%s\" does not exist",
722 : parentattno, get_rel_name(context->parent_reloid));
723 4981 : childvar = (Var *) list_nth(context->translated_vars, parentattno - 1);
724 4981 : if (childvar == NULL || !IsA(childvar, Var))
725 0 : elog(ERROR, "attribute %d of relation \"%s\" does not exist",
726 : parentattno, get_rel_name(context->parent_reloid));
727 :
728 4981 : result = lappend_int(result, childvar->varattno);
729 : }
730 4038 : return result;
731 : }
732 :
733 : /*
734 : * adjust_inherited_attnums_multilevel
735 : * As above, but traverse multiple inheritance levels as needed.
736 : */
737 : List *
738 4038 : adjust_inherited_attnums_multilevel(PlannerInfo *root, List *attnums,
739 : Index child_relid, Index top_parent_relid)
740 : {
741 4038 : AppendRelInfo *appinfo = root->append_rel_array[child_relid];
742 :
743 4038 : if (!appinfo)
744 0 : elog(ERROR, "child rel %d not found in append_rel_array", child_relid);
745 :
746 : /* Recurse if immediate parent is not the top parent. */
747 4038 : if (appinfo->parent_relid != top_parent_relid)
748 677 : attnums = adjust_inherited_attnums_multilevel(root, attnums,
749 : appinfo->parent_relid,
750 : top_parent_relid);
751 :
752 : /* Now translate for this child */
753 4038 : return adjust_inherited_attnums(attnums, appinfo);
754 : }
755 :
756 : /*
757 : * get_translated_update_targetlist
758 : * Get the processed_tlist of an UPDATE query, translated as needed to
759 : * match a child target relation.
760 : *
761 : * Optionally also return the list of target column numbers translated
762 : * to this target relation. (The resnos in processed_tlist MUST NOT be
763 : * relied on for this purpose.)
764 : */
765 : void
766 50 : get_translated_update_targetlist(PlannerInfo *root, Index relid,
767 : List **processed_tlist, List **update_colnos)
768 : {
769 : /* This is pretty meaningless for commands other than UPDATE. */
770 : Assert(root->parse->commandType == CMD_UPDATE);
771 50 : if (relid == root->parse->resultRelation)
772 : {
773 : /*
774 : * Non-inheritance case, so it's easy. The caller might be expecting
775 : * a tree it can scribble on, though, so copy.
776 : */
777 33 : *processed_tlist = copyObject(root->processed_tlist);
778 33 : if (update_colnos)
779 33 : *update_colnos = copyObject(root->update_colnos);
780 : }
781 : else
782 : {
783 : Assert(bms_is_member(relid, root->all_result_relids));
784 17 : *processed_tlist = (List *)
785 17 : adjust_appendrel_attrs_multilevel(root,
786 17 : (Node *) root->processed_tlist,
787 : find_base_rel(root, relid),
788 17 : find_base_rel(root, root->parse->resultRelation));
789 17 : if (update_colnos)
790 17 : *update_colnos =
791 17 : adjust_inherited_attnums_multilevel(root, root->update_colnos,
792 : relid,
793 17 : root->parse->resultRelation);
794 : }
795 50 : }
796 :
797 : /*
798 : * find_appinfos_by_relids
799 : * Find AppendRelInfo structures for base relations listed in relids.
800 : *
801 : * The relids argument is typically a join relation's relids, which can
802 : * include outer-join RT indexes in addition to baserels. We silently
803 : * ignore the outer joins.
804 : *
805 : * The AppendRelInfos are returned in an array, which can be pfree'd by the
806 : * caller. *nappinfos is set to the number of entries in the array.
807 : */
808 : AppendRelInfo **
809 83057 : find_appinfos_by_relids(PlannerInfo *root, Relids relids, int *nappinfos)
810 : {
811 : AppendRelInfo **appinfos;
812 83057 : int cnt = 0;
813 : int i;
814 :
815 : /* Allocate an array that's certainly big enough */
816 83057 : appinfos = palloc_array(AppendRelInfo *, bms_num_members(relids));
817 :
818 83057 : i = -1;
819 209299 : while ((i = bms_next_member(relids, i)) >= 0)
820 : {
821 126242 : AppendRelInfo *appinfo = root->append_rel_array[i];
822 :
823 126242 : if (!appinfo)
824 : {
825 : /* Probably i is an OJ index, but let's check */
826 2976 : if (find_base_rel_ignore_join(root, i) == NULL)
827 2976 : continue;
828 : /* It's a base rel, but we lack an append_rel_array entry */
829 0 : elog(ERROR, "child rel %d not found in append_rel_array", i);
830 : }
831 :
832 123266 : appinfos[cnt++] = appinfo;
833 : }
834 83057 : *nappinfos = cnt;
835 83057 : return appinfos;
836 : }
837 :
838 :
839 : /*****************************************************************************
840 : *
841 : * ROW-IDENTITY VARIABLE MANAGEMENT
842 : *
843 : * This code lacks a good home, perhaps. We choose to keep it here because
844 : * adjust_appendrel_attrs_mutator() is its principal co-conspirator. That
845 : * function does most of what is needed to expand ROWID_VAR Vars into the
846 : * right things.
847 : *
848 : *****************************************************************************/
849 :
850 : /*
851 : * add_row_identity_var
852 : * Register a row-identity column to be used in UPDATE/DELETE/MERGE.
853 : *
854 : * The Var must be equal(), aside from varno, to any other row-identity
855 : * column with the same rowid_name. Thus, for example, "wholerow"
856 : * row identities had better use vartype == RECORDOID.
857 : *
858 : * rtindex is currently redundant with rowid_var->varno, but we specify
859 : * it as a separate parameter in case this is ever generalized to support
860 : * non-Var expressions. (We could reasonably handle expressions over
861 : * Vars of the specified rtindex, but for now that seems unnecessary.)
862 : */
863 : void
864 20769 : add_row_identity_var(PlannerInfo *root, Var *orig_var,
865 : Index rtindex, const char *rowid_name)
866 : {
867 : TargetEntry *tle;
868 : Var *rowid_var;
869 : RowIdentityVarInfo *ridinfo;
870 : ListCell *lc;
871 :
872 : /* For now, the argument must be just a Var of the given rtindex */
873 : Assert(IsA(orig_var, Var));
874 : Assert(orig_var->varno == rtindex);
875 : Assert(orig_var->varlevelsup == 0);
876 : Assert(orig_var->varnullingrels == NULL);
877 :
878 : /*
879 : * If we're doing non-inherited UPDATE/DELETE/MERGE, there's little need
880 : * for ROWID_VAR shenanigans. Just shove the presented Var into the
881 : * processed_tlist, and we're done.
882 : */
883 20769 : if (rtindex == root->parse->resultRelation)
884 : {
885 12050 : tle = makeTargetEntry((Expr *) orig_var,
886 12050 : list_length(root->processed_tlist) + 1,
887 : pstrdup(rowid_name),
888 : true);
889 12050 : root->processed_tlist = lappend(root->processed_tlist, tle);
890 12050 : return;
891 : }
892 :
893 : /*
894 : * Otherwise, rtindex should reference a leaf target relation that's being
895 : * added to the query during expand_inherited_rtentry().
896 : */
897 : Assert(bms_is_member(rtindex, root->leaf_result_relids));
898 : Assert(root->append_rel_array[rtindex] != NULL);
899 :
900 : /*
901 : * We have to find a matching RowIdentityVarInfo, or make one if there is
902 : * none. To allow using equal() to match the vars, change the varno to
903 : * ROWID_VAR, leaving all else alone.
904 : */
905 8719 : rowid_var = copyObject(orig_var);
906 : /* This could eventually become ChangeVarNodes() */
907 8719 : rowid_var->varno = ROWID_VAR;
908 :
909 : /* Look for an existing row-id column of the same name */
910 13141 : foreach(lc, root->row_identity_vars)
911 : {
912 8666 : ridinfo = (RowIdentityVarInfo *) lfirst(lc);
913 8666 : if (strcmp(rowid_name, ridinfo->rowidname) != 0)
914 4422 : continue;
915 4244 : if (equal(rowid_var, ridinfo->rowidvar))
916 : {
917 : /* Found a match; we need only record that rtindex needs it too */
918 4244 : ridinfo->rowidrels = bms_add_member(ridinfo->rowidrels, rtindex);
919 4244 : return;
920 : }
921 : else
922 : {
923 : /* Ooops, can't handle this */
924 0 : elog(ERROR, "conflicting uses of row-identity name \"%s\"",
925 : rowid_name);
926 : }
927 : }
928 :
929 : /* No request yet, so add a new RowIdentityVarInfo */
930 4475 : ridinfo = makeNode(RowIdentityVarInfo);
931 4475 : ridinfo->rowidvar = copyObject(rowid_var);
932 : /* for the moment, estimate width using just the datatype info */
933 4475 : ridinfo->rowidwidth = get_typavgwidth(exprType((Node *) rowid_var),
934 : exprTypmod((Node *) rowid_var));
935 4475 : ridinfo->rowidname = pstrdup(rowid_name);
936 4475 : ridinfo->rowidrels = bms_make_singleton(rtindex);
937 :
938 4475 : root->row_identity_vars = lappend(root->row_identity_vars, ridinfo);
939 :
940 : /* Change rowid_var into a reference to this row_identity_vars entry */
941 4475 : rowid_var->varattno = list_length(root->row_identity_vars);
942 :
943 : /* Push the ROWID_VAR reference variable into processed_tlist */
944 4475 : tle = makeTargetEntry((Expr *) rowid_var,
945 4475 : list_length(root->processed_tlist) + 1,
946 : pstrdup(rowid_name),
947 : true);
948 4475 : root->processed_tlist = lappend(root->processed_tlist, tle);
949 : }
950 :
951 : /*
952 : * add_row_identity_columns
953 : *
954 : * This function adds the row identity columns needed by the core code.
955 : * FDWs might call add_row_identity_var() for themselves to add nonstandard
956 : * columns. (Duplicate requests are fine.)
957 : */
958 : void
959 16561 : add_row_identity_columns(PlannerInfo *root, Index rtindex,
960 : RangeTblEntry *target_rte,
961 : Relation target_relation)
962 : {
963 16561 : CmdType commandType = root->parse->commandType;
964 16561 : char relkind = target_relation->rd_rel->relkind;
965 : Var *var;
966 :
967 : Assert(commandType == CMD_UPDATE || commandType == CMD_DELETE || commandType == CMD_MERGE);
968 :
969 16561 : if (relkind == RELKIND_RELATION ||
970 470 : relkind == RELKIND_MATVIEW ||
971 : relkind == RELKIND_PARTITIONED_TABLE)
972 : {
973 : /*
974 : * Emit CTID so that executor can find the row to merge, update or
975 : * delete.
976 : */
977 16124 : var = makeVar(rtindex,
978 : SelfItemPointerAttributeNumber,
979 : TIDOID,
980 : -1,
981 : InvalidOid,
982 : 0);
983 16124 : add_row_identity_var(root, var, rtindex, "ctid");
984 : }
985 437 : else if (relkind == RELKIND_FOREIGN_TABLE)
986 : {
987 : /*
988 : * Let the foreign table's FDW add whatever junk TLEs it wants.
989 : */
990 : FdwRoutine *fdwroutine;
991 :
992 196 : fdwroutine = GetFdwRoutineForRelation(target_relation, false);
993 :
994 196 : if (fdwroutine->AddForeignUpdateTargets != NULL)
995 189 : fdwroutine->AddForeignUpdateTargets(root, rtindex,
996 : target_rte, target_relation);
997 :
998 : /*
999 : * For UPDATE, we need to make the FDW fetch unchanged columns by
1000 : * asking it to fetch a whole-row Var. That's because the top-level
1001 : * targetlist only contains entries for changed columns, but
1002 : * ExecUpdate will need to build the complete new tuple. (Actually,
1003 : * we only really need this in UPDATEs that are not pushed to the
1004 : * remote side, but it's hard to tell if that will be the case at the
1005 : * point when this function is called.)
1006 : *
1007 : * We will also need the whole row if there are any row triggers, so
1008 : * that the executor will have the "old" row to pass to the trigger.
1009 : * Alas, this misses system columns.
1010 : */
1011 196 : if (commandType == CMD_UPDATE ||
1012 88 : (target_relation->trigdesc &&
1013 15 : (target_relation->trigdesc->trig_delete_after_row ||
1014 9 : target_relation->trigdesc->trig_delete_before_row)))
1015 : {
1016 116 : var = makeVar(rtindex,
1017 : InvalidAttrNumber,
1018 : RECORDOID,
1019 : -1,
1020 : InvalidOid,
1021 : 0);
1022 116 : add_row_identity_var(root, var, rtindex, "wholerow");
1023 : }
1024 : }
1025 16561 : }
1026 :
1027 : /*
1028 : * distribute_row_identity_vars
1029 : *
1030 : * After we have finished identifying all the row identity columns
1031 : * needed by an inherited UPDATE/DELETE/MERGE query, make sure that
1032 : * these columns will be generated by all the target relations.
1033 : *
1034 : * This is more or less like what build_base_rel_tlists() does,
1035 : * except that it would not understand what to do with ROWID_VAR Vars.
1036 : * Since that function runs before inheritance relations are expanded,
1037 : * it will never see any such Vars anyway.
1038 : */
1039 : void
1040 252078 : distribute_row_identity_vars(PlannerInfo *root)
1041 : {
1042 252078 : Query *parse = root->parse;
1043 252078 : int result_relation = parse->resultRelation;
1044 : RangeTblEntry *target_rte;
1045 : RelOptInfo *target_rel;
1046 : ListCell *lc;
1047 :
1048 : /*
1049 : * There's nothing to do if this isn't an inherited UPDATE/DELETE/MERGE.
1050 : */
1051 252078 : if (parse->commandType != CMD_UPDATE && parse->commandType != CMD_DELETE &&
1052 239115 : parse->commandType != CMD_MERGE)
1053 : {
1054 : Assert(root->row_identity_vars == NIL);
1055 237645 : return;
1056 : }
1057 14433 : target_rte = rt_fetch(result_relation, parse->rtable);
1058 14433 : if (!target_rte->inh)
1059 : {
1060 : Assert(root->row_identity_vars == NIL);
1061 12187 : return;
1062 : }
1063 :
1064 : /*
1065 : * Ordinarily, we expect that leaf result relation(s) will have added some
1066 : * ROWID_VAR Vars to the query. However, it's possible that constraint
1067 : * exclusion suppressed every leaf relation. The executor will get upset
1068 : * if the plan has no row identity columns at all, even though it will
1069 : * certainly process no rows. Handle this edge case by re-opening the top
1070 : * result relation and adding the row identity columns it would have used,
1071 : * as preprocess_targetlist() would have done if it weren't marked "inh".
1072 : * Then re-run build_base_rel_tlists() to ensure that the added columns
1073 : * get propagated to the relation's reltarget. (This is a bit ugly, but
1074 : * it seems better to confine the ugliness and extra cycles to this
1075 : * unusual corner case.)
1076 : */
1077 2246 : if (root->row_identity_vars == NIL)
1078 : {
1079 : Relation target_relation;
1080 :
1081 28 : target_relation = table_open(target_rte->relid, NoLock);
1082 28 : add_row_identity_columns(root, result_relation,
1083 : target_rte, target_relation);
1084 28 : table_close(target_relation, NoLock);
1085 28 : build_base_rel_tlists(root, root->processed_tlist);
1086 : /* There are no ROWID_VAR Vars in this case, so we're done. */
1087 28 : return;
1088 : }
1089 :
1090 : /*
1091 : * Dig through the processed_tlist to find the ROWID_VAR reference Vars,
1092 : * and forcibly copy them into the reltarget list of the topmost target
1093 : * relation. That's sufficient because they'll be copied to the
1094 : * individual leaf target rels (with appropriate translation) later,
1095 : * during appendrel expansion --- see set_append_rel_size().
1096 : */
1097 2218 : target_rel = find_base_rel(root, result_relation);
1098 :
1099 9303 : foreach(lc, root->processed_tlist)
1100 : {
1101 7085 : TargetEntry *tle = lfirst(lc);
1102 7085 : Var *var = (Var *) tle->expr;
1103 :
1104 7085 : if (var && IsA(var, Var) && var->varno == ROWID_VAR)
1105 : {
1106 4475 : target_rel->reltarget->exprs =
1107 4475 : lappend(target_rel->reltarget->exprs, copyObject(var));
1108 : /* reltarget cost and width will be computed later */
1109 : }
1110 : }
1111 : }
|
