Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * prepare.c
4 : * Prepareable SQL statements via PREPARE, EXECUTE and DEALLOCATE
5 : *
6 : * This module also implements storage of prepared statements that are
7 : * accessed via the extended FE/BE query protocol.
8 : *
9 : *
10 : * Copyright (c) 2002-2026, PostgreSQL Global Development Group
11 : *
12 : * IDENTIFICATION
13 : * src/backend/commands/prepare.c
14 : *
15 : *-------------------------------------------------------------------------
16 : */
17 : #include "postgres.h"
18 :
19 : #include <limits.h>
20 :
21 : #include "access/xact.h"
22 : #include "catalog/pg_type.h"
23 : #include "commands/createas.h"
24 : #include "commands/explain.h"
25 : #include "commands/explain_format.h"
26 : #include "commands/explain_state.h"
27 : #include "commands/prepare.h"
28 : #include "funcapi.h"
29 : #include "nodes/nodeFuncs.h"
30 : #include "parser/parse_coerce.h"
31 : #include "parser/parse_collate.h"
32 : #include "parser/parse_expr.h"
33 : #include "parser/parse_type.h"
34 : #include "tcop/pquery.h"
35 : #include "tcop/utility.h"
36 : #include "utils/builtins.h"
37 : #include "utils/hsearch.h"
38 : #include "utils/snapmgr.h"
39 : #include "utils/timestamp.h"
40 : #include "utils/tuplestore.h"
41 :
42 :
43 : /*
44 : * The hash table in which prepared queries are stored. This is
45 : * per-backend: query plans are not shared between backends.
46 : * The keys for this hash table are the arguments to PREPARE and EXECUTE
47 : * (statement names); the entries are PreparedStatement structs.
48 : */
49 : static HTAB *prepared_queries = NULL;
50 :
51 : static void InitQueryHashTable(void);
52 : static ParamListInfo EvaluateParams(ParseState *pstate,
53 : PreparedStatement *pstmt, List *params,
54 : EState *estate);
55 : static Datum build_regtype_array(Oid *param_types, int num_params);
56 :
57 : /*
58 : * Implements the 'PREPARE' utility statement.
59 : */
60 : void
61 1185 : PrepareQuery(ParseState *pstate, PrepareStmt *stmt,
62 : int stmt_location, int stmt_len)
63 : {
64 : RawStmt *rawstmt;
65 : CachedPlanSource *plansource;
66 1185 : Oid *argtypes = NULL;
67 : int nargs;
68 : List *query_list;
69 :
70 : /*
71 : * Disallow empty-string statement name (conflicts with protocol-level
72 : * unnamed statement).
73 : */
74 1185 : if (!stmt->name || stmt->name[0] == '\0')
75 0 : ereport(ERROR,
76 : (errcode(ERRCODE_INVALID_PSTATEMENT_DEFINITION),
77 : errmsg("invalid statement name: must not be empty")));
78 :
79 : /*
80 : * Need to wrap the contained statement in a RawStmt node to pass it to
81 : * parse analysis.
82 : */
83 1185 : rawstmt = makeNode(RawStmt);
84 1185 : rawstmt->stmt = stmt->query;
85 1185 : rawstmt->stmt_location = stmt_location;
86 1185 : rawstmt->stmt_len = stmt_len;
87 :
88 : /*
89 : * Create the CachedPlanSource before we do parse analysis, since it needs
90 : * to see the unmodified raw parse tree.
91 : */
92 1185 : plansource = CreateCachedPlan(rawstmt, pstate->p_sourcetext,
93 : CreateCommandTag(stmt->query));
94 :
95 : /* Transform list of TypeNames to array of type OIDs */
96 1185 : nargs = list_length(stmt->argtypes);
97 :
98 1185 : if (nargs)
99 : {
100 : int i;
101 : ListCell *l;
102 :
103 960 : argtypes = palloc_array(Oid, nargs);
104 960 : i = 0;
105 :
106 2070 : foreach(l, stmt->argtypes)
107 : {
108 1114 : TypeName *tn = lfirst(l);
109 1114 : Oid toid = typenameTypeId(pstate, tn);
110 :
111 1110 : argtypes[i++] = toid;
112 : }
113 : }
114 :
115 : /*
116 : * Analyze the statement using these parameter types (any parameters
117 : * passed in from above us will not be visible to it), allowing
118 : * information about unknown parameters to be deduced from context.
119 : * Rewrite the query. The result could be 0, 1, or many queries.
120 : */
121 1181 : query_list = pg_analyze_and_rewrite_varparams(rawstmt, pstate->p_sourcetext,
122 : &argtypes, &nargs, NULL);
123 :
124 : /* Finish filling in the CachedPlanSource */
125 1181 : CompleteCachedPlan(plansource,
126 : query_list,
127 : NULL,
128 : argtypes,
129 : nargs,
130 : NULL,
131 : NULL,
132 : CURSOR_OPT_PARALLEL_OK, /* allow parallel mode */
133 : true); /* fixed result */
134 :
135 : /*
136 : * Save the results.
137 : */
138 1181 : StorePreparedStatement(stmt->name,
139 : plansource,
140 : true);
141 1177 : }
142 :
143 : /*
144 : * ExecuteQuery --- implement the 'EXECUTE' utility statement.
145 : *
146 : * This code also supports CREATE TABLE ... AS EXECUTE. That case is
147 : * indicated by passing a non-null intoClause. The DestReceiver is already
148 : * set up correctly for CREATE TABLE AS, but we still have to make a few
149 : * other adjustments here.
150 : */
151 : void
152 8618 : ExecuteQuery(ParseState *pstate,
153 : ExecuteStmt *stmt, IntoClause *intoClause,
154 : ParamListInfo params,
155 : DestReceiver *dest, QueryCompletion *qc)
156 : {
157 : PreparedStatement *entry;
158 : CachedPlan *cplan;
159 : List *plan_list;
160 8618 : ParamListInfo paramLI = NULL;
161 8618 : EState *estate = NULL;
162 : Portal portal;
163 : char *query_string;
164 : int eflags;
165 : long count;
166 :
167 : /* Look it up in the hash table */
168 8618 : entry = FetchPreparedStatement(stmt->name, true);
169 :
170 : /* Shouldn't find a non-fixed-result cached plan */
171 8618 : if (!entry->plansource->fixed_result)
172 0 : elog(ERROR, "EXECUTE does not support variable-result cached plans");
173 :
174 : /* Evaluate parameters, if any */
175 8618 : if (entry->plansource->num_params > 0)
176 : {
177 : /*
178 : * Need an EState to evaluate parameters; must not delete it till end
179 : * of query, in case parameters are pass-by-reference. Note that the
180 : * passed-in "params" could possibly be referenced in the parameter
181 : * expressions.
182 : */
183 7798 : estate = CreateExecutorState();
184 7798 : estate->es_param_list_info = params;
185 7798 : paramLI = EvaluateParams(pstate, entry, stmt->params, estate);
186 : }
187 :
188 : /* Create a new portal to run the query in */
189 8594 : portal = CreateNewPortal();
190 : /* Don't display the portal in pg_cursors, it is for internal use only */
191 8594 : portal->visible = false;
192 :
193 : /* Copy the plan's saved query string into the portal's memory */
194 8594 : query_string = MemoryContextStrdup(portal->portalContext,
195 8594 : entry->plansource->query_string);
196 :
197 : /* Replan if needed, and increment plan refcount for portal */
198 8594 : cplan = GetCachedPlan(entry->plansource, paramLI, NULL, NULL);
199 8550 : plan_list = cplan->stmt_list;
200 :
201 : /*
202 : * DO NOT add any logic that could possibly throw an error between
203 : * GetCachedPlan and PortalDefineQuery, or you'll leak the plan refcount.
204 : */
205 8550 : PortalDefineQuery(portal,
206 : NULL,
207 : query_string,
208 8550 : entry->plansource->commandTag,
209 : plan_list,
210 : cplan);
211 :
212 : /*
213 : * For CREATE TABLE ... AS EXECUTE, we must verify that the prepared
214 : * statement is one that produces tuples. Currently we insist that it be
215 : * a plain old SELECT. In future we might consider supporting other
216 : * things such as INSERT ... RETURNING, but there are a couple of issues
217 : * to be settled first, notably how WITH NO DATA should be handled in such
218 : * a case (do we really want to suppress execution?) and how to pass down
219 : * the OID-determining eflags (PortalStart won't handle them in such a
220 : * case, and for that matter it's not clear the executor will either).
221 : *
222 : * For CREATE TABLE ... AS EXECUTE, we also have to ensure that the proper
223 : * eflags and fetch count are passed to PortalStart/PortalRun.
224 : */
225 8550 : if (intoClause)
226 : {
227 : PlannedStmt *pstmt;
228 :
229 30 : if (list_length(plan_list) != 1)
230 0 : ereport(ERROR,
231 : (errcode(ERRCODE_WRONG_OBJECT_TYPE),
232 : errmsg("prepared statement is not a SELECT")));
233 30 : pstmt = linitial_node(PlannedStmt, plan_list);
234 30 : if (pstmt->commandType != CMD_SELECT)
235 0 : ereport(ERROR,
236 : (errcode(ERRCODE_WRONG_OBJECT_TYPE),
237 : errmsg("prepared statement is not a SELECT")));
238 :
239 : /* Set appropriate eflags */
240 30 : eflags = GetIntoRelEFlags(intoClause);
241 :
242 : /* And tell PortalRun whether to run to completion or not */
243 30 : if (intoClause->skipData)
244 8 : count = 0;
245 : else
246 22 : count = FETCH_ALL;
247 : }
248 : else
249 : {
250 : /* Plain old EXECUTE */
251 8520 : eflags = 0;
252 8520 : count = FETCH_ALL;
253 : }
254 :
255 : /*
256 : * Run the portal as appropriate.
257 : */
258 8550 : PortalStart(portal, paramLI, eflags, GetActiveSnapshot());
259 :
260 8550 : (void) PortalRun(portal, count, false, dest, dest, qc);
261 :
262 8525 : PortalDrop(portal, false);
263 :
264 8525 : if (estate)
265 7746 : FreeExecutorState(estate);
266 :
267 : /* No need to pfree other memory, MemoryContext will be reset */
268 8525 : }
269 :
270 : /*
271 : * EvaluateParams: evaluate a list of parameters.
272 : *
273 : * pstate: parse state
274 : * pstmt: statement we are getting parameters for.
275 : * params: list of given parameter expressions (raw parser output!)
276 : * estate: executor state to use.
277 : *
278 : * Returns a filled-in ParamListInfo -- this can later be passed to
279 : * CreateQueryDesc(), which allows the executor to make use of the parameters
280 : * during query execution.
281 : */
282 : static ParamListInfo
283 7988 : EvaluateParams(ParseState *pstate, PreparedStatement *pstmt, List *params,
284 : EState *estate)
285 : {
286 7988 : Oid *param_types = pstmt->plansource->param_types;
287 7988 : int num_params = pstmt->plansource->num_params;
288 7988 : int nparams = list_length(params);
289 : ParamListInfo paramLI;
290 : List *exprstates;
291 : ListCell *l;
292 : int i;
293 :
294 7988 : if (nparams != num_params)
295 8 : ereport(ERROR,
296 : (errcode(ERRCODE_SYNTAX_ERROR),
297 : errmsg("wrong number of parameters for prepared statement \"%s\"",
298 : pstmt->stmt_name),
299 : errdetail("Expected %d parameters but got %d.",
300 : num_params, nparams)));
301 :
302 : /* Quick exit if no parameters */
303 7980 : if (num_params == 0)
304 0 : return NULL;
305 :
306 : /*
307 : * We have to run parse analysis for the expressions. Since the parser is
308 : * not cool about scribbling on its input, copy first.
309 : */
310 7980 : params = copyObject(params);
311 :
312 7980 : i = 0;
313 16349 : foreach(l, params)
314 : {
315 8377 : Node *expr = lfirst(l);
316 8377 : Oid expected_type_id = param_types[i];
317 : Oid given_type_id;
318 :
319 8377 : expr = transformExpr(pstate, expr, EXPR_KIND_EXECUTE_PARAMETER);
320 :
321 8377 : given_type_id = exprType(expr);
322 :
323 8377 : expr = coerce_to_target_type(pstate, expr, given_type_id,
324 : expected_type_id, -1,
325 : COERCION_ASSIGNMENT,
326 : COERCE_IMPLICIT_CAST,
327 : -1);
328 :
329 8373 : if (expr == NULL)
330 4 : ereport(ERROR,
331 : (errcode(ERRCODE_DATATYPE_MISMATCH),
332 : errmsg("parameter $%d of type %s cannot be coerced to the expected type %s",
333 : i + 1,
334 : format_type_be(given_type_id),
335 : format_type_be(expected_type_id)),
336 : errhint("You will need to rewrite or cast the expression."),
337 : parser_errposition(pstate, exprLocation(lfirst(l)))));
338 :
339 : /* Take care of collations in the finished expression. */
340 8369 : assign_expr_collations(pstate, expr);
341 :
342 8369 : lfirst(l) = expr;
343 8369 : i++;
344 : }
345 :
346 : /* Prepare the expressions for execution */
347 7972 : exprstates = ExecPrepareExprList(params, estate);
348 :
349 7972 : paramLI = makeParamList(num_params);
350 :
351 7972 : i = 0;
352 16325 : foreach(l, exprstates)
353 : {
354 8361 : ExprState *n = (ExprState *) lfirst(l);
355 8361 : ParamExternData *prm = ¶mLI->params[i];
356 :
357 8361 : prm->ptype = param_types[i];
358 8361 : prm->pflags = PARAM_FLAG_CONST;
359 8361 : prm->value = ExecEvalExprSwitchContext(n,
360 8361 : GetPerTupleExprContext(estate),
361 : &prm->isnull);
362 :
363 8353 : i++;
364 : }
365 :
366 7964 : return paramLI;
367 : }
368 :
369 :
370 : /*
371 : * Initialize query hash table upon first use.
372 : */
373 : static void
374 665 : InitQueryHashTable(void)
375 : {
376 : HASHCTL hash_ctl;
377 :
378 665 : hash_ctl.keysize = NAMEDATALEN;
379 665 : hash_ctl.entrysize = sizeof(PreparedStatement);
380 :
381 665 : prepared_queries = hash_create("Prepared Queries",
382 : 32,
383 : &hash_ctl,
384 : HASH_ELEM | HASH_STRINGS);
385 665 : }
386 :
387 : /*
388 : * Store all the data pertaining to a query in the hash table using
389 : * the specified key. The passed CachedPlanSource should be "unsaved"
390 : * in case we get an error here; we'll save it once we've created the hash
391 : * table entry.
392 : */
393 : void
394 3380 : StorePreparedStatement(const char *stmt_name,
395 : CachedPlanSource *plansource,
396 : bool from_sql)
397 : {
398 : PreparedStatement *entry;
399 3380 : TimestampTz cur_ts = GetCurrentStatementStartTimestamp();
400 : bool found;
401 :
402 : /* Initialize the hash table, if necessary */
403 3380 : if (!prepared_queries)
404 665 : InitQueryHashTable();
405 :
406 : /* Add entry to hash table */
407 3380 : entry = (PreparedStatement *) hash_search(prepared_queries,
408 : stmt_name,
409 : HASH_ENTER,
410 : &found);
411 :
412 : /* Shouldn't get a duplicate entry */
413 3380 : if (found)
414 4 : ereport(ERROR,
415 : (errcode(ERRCODE_DUPLICATE_PSTATEMENT),
416 : errmsg("prepared statement \"%s\" already exists",
417 : stmt_name)));
418 :
419 : /* Fill in the hash table entry */
420 3376 : entry->plansource = plansource;
421 3376 : entry->from_sql = from_sql;
422 3376 : entry->prepare_time = cur_ts;
423 :
424 : /* Now it's safe to move the CachedPlanSource to permanent memory */
425 3376 : SaveCachedPlan(plansource);
426 3376 : }
427 :
428 : /*
429 : * Lookup an existing query in the hash table. If the query does not
430 : * actually exist, throw ereport(ERROR) or return NULL per second parameter.
431 : *
432 : * Note: this does not force the referenced plancache entry to be valid,
433 : * since not all callers care.
434 : */
435 : PreparedStatement *
436 50147 : FetchPreparedStatement(const char *stmt_name, bool throwError)
437 : {
438 : PreparedStatement *entry;
439 :
440 : /*
441 : * If the hash table hasn't been initialized, it can't be storing
442 : * anything, therefore it couldn't possibly store our plan.
443 : */
444 50147 : if (prepared_queries)
445 50146 : entry = (PreparedStatement *) hash_search(prepared_queries,
446 : stmt_name,
447 : HASH_FIND,
448 : NULL);
449 : else
450 1 : entry = NULL;
451 :
452 50147 : if (!entry && throwError)
453 6 : ereport(ERROR,
454 : (errcode(ERRCODE_UNDEFINED_PSTATEMENT),
455 : errmsg("prepared statement \"%s\" does not exist",
456 : stmt_name)));
457 :
458 50141 : return entry;
459 : }
460 :
461 : /*
462 : * Given a prepared statement, determine the result tupledesc it will
463 : * produce. Returns NULL if the execution will not return tuples.
464 : *
465 : * Note: the result is created or copied into current memory context.
466 : */
467 : TupleDesc
468 8521 : FetchPreparedStatementResultDesc(PreparedStatement *stmt)
469 : {
470 : /*
471 : * Since we don't allow prepared statements' result tupdescs to change,
472 : * there's no need to worry about revalidating the cached plan here.
473 : */
474 : Assert(stmt->plansource->fixed_result);
475 8521 : if (stmt->plansource->resultDesc)
476 8521 : return CreateTupleDescCopy(stmt->plansource->resultDesc);
477 : else
478 0 : return NULL;
479 : }
480 :
481 : /*
482 : * Given a prepared statement that returns tuples, extract the query
483 : * targetlist. Returns NIL if the statement doesn't have a determinable
484 : * targetlist.
485 : *
486 : * Note: this is pretty ugly, but since it's only used in corner cases like
487 : * Describe Statement on an EXECUTE command, we don't worry too much about
488 : * efficiency.
489 : */
490 : List *
491 8448 : FetchPreparedStatementTargetList(PreparedStatement *stmt)
492 : {
493 : List *tlist;
494 :
495 : /* Get the plan's primary targetlist */
496 8448 : tlist = CachedPlanGetTargetList(stmt->plansource, NULL);
497 :
498 : /* Copy into caller's context in case plan gets invalidated */
499 8448 : return copyObject(tlist);
500 : }
501 :
502 : /*
503 : * Implements the 'DEALLOCATE' utility statement: deletes the
504 : * specified plan from storage.
505 : */
506 : void
507 2093 : DeallocateQuery(DeallocateStmt *stmt)
508 : {
509 2093 : if (stmt->name)
510 2056 : DropPreparedStatement(stmt->name, true);
511 : else
512 37 : DropAllPreparedStatements();
513 2093 : }
514 :
515 : /*
516 : * Internal version of DEALLOCATE
517 : *
518 : * If showError is false, dropping a nonexistent statement is a no-op.
519 : */
520 : void
521 2071 : DropPreparedStatement(const char *stmt_name, bool showError)
522 : {
523 : PreparedStatement *entry;
524 :
525 : /* Find the query's hash table entry; raise error if wanted */
526 2071 : entry = FetchPreparedStatement(stmt_name, showError);
527 :
528 2071 : if (entry)
529 : {
530 : /* Release the plancache entry */
531 2066 : DropCachedPlan(entry->plansource);
532 :
533 : /* Now we can remove the hash table entry */
534 2066 : hash_search(prepared_queries, entry->stmt_name, HASH_REMOVE, NULL);
535 : }
536 2071 : }
537 :
538 : /*
539 : * Drop all cached statements.
540 : */
541 : void
542 41 : DropAllPreparedStatements(void)
543 : {
544 : HASH_SEQ_STATUS seq;
545 : PreparedStatement *entry;
546 :
547 : /* nothing cached */
548 41 : if (!prepared_queries)
549 0 : return;
550 :
551 : /* walk over cache */
552 41 : hash_seq_init(&seq, prepared_queries);
553 89 : while ((entry = hash_seq_search(&seq)) != NULL)
554 : {
555 : /* Release the plancache entry */
556 48 : DropCachedPlan(entry->plansource);
557 :
558 : /* Now we can remove the hash table entry */
559 48 : hash_search(prepared_queries, entry->stmt_name, HASH_REMOVE, NULL);
560 : }
561 : }
562 :
563 : /*
564 : * Implements the 'EXPLAIN EXECUTE' utility statement.
565 : *
566 : * "into" is NULL unless we are doing EXPLAIN CREATE TABLE AS EXECUTE,
567 : * in which case executing the query should result in creating that table.
568 : *
569 : * Note: the passed-in pstate's queryString is that of the EXPLAIN EXECUTE,
570 : * not the original PREPARE; we get the latter string from the plancache.
571 : */
572 : void
573 278 : ExplainExecuteQuery(ExecuteStmt *execstmt, IntoClause *into, ExplainState *es,
574 : ParseState *pstate, ParamListInfo params)
575 : {
576 : PreparedStatement *entry;
577 : const char *query_string;
578 : CachedPlan *cplan;
579 : List *plan_list;
580 : ListCell *p;
581 278 : ParamListInfo paramLI = NULL;
582 278 : EState *estate = NULL;
583 : instr_time planstart;
584 : instr_time planduration;
585 : BufferUsage bufusage_start,
586 : bufusage;
587 : MemoryContextCounters mem_counters;
588 278 : MemoryContext planner_ctx = NULL;
589 278 : MemoryContext saved_ctx = NULL;
590 :
591 278 : if (es->memory)
592 : {
593 : /* See ExplainOneQuery about this */
594 : Assert(IsA(CurrentMemoryContext, AllocSetContext));
595 4 : planner_ctx = AllocSetContextCreate(CurrentMemoryContext,
596 : "explain analyze planner context",
597 : ALLOCSET_DEFAULT_SIZES);
598 4 : saved_ctx = MemoryContextSwitchTo(planner_ctx);
599 : }
600 :
601 278 : if (es->buffers)
602 0 : bufusage_start = pgBufferUsage;
603 278 : INSTR_TIME_SET_CURRENT(planstart);
604 :
605 : /* Look it up in the hash table */
606 278 : entry = FetchPreparedStatement(execstmt->name, true);
607 :
608 : /* Shouldn't find a non-fixed-result cached plan */
609 278 : if (!entry->plansource->fixed_result)
610 0 : elog(ERROR, "EXPLAIN EXECUTE does not support variable-result cached plans");
611 :
612 278 : query_string = entry->plansource->query_string;
613 :
614 : /* Evaluate parameters, if any */
615 278 : if (entry->plansource->num_params)
616 : {
617 : ParseState *pstate_params;
618 :
619 190 : pstate_params = make_parsestate(NULL);
620 190 : pstate_params->p_sourcetext = pstate->p_sourcetext;
621 :
622 : /*
623 : * Need an EState to evaluate parameters; must not delete it till end
624 : * of query, in case parameters are pass-by-reference. Note that the
625 : * passed-in "params" could possibly be referenced in the parameter
626 : * expressions.
627 : */
628 190 : estate = CreateExecutorState();
629 190 : estate->es_param_list_info = params;
630 :
631 190 : paramLI = EvaluateParams(pstate_params, entry, execstmt->params, estate);
632 : }
633 :
634 : /* Replan if needed, and acquire a transient refcount */
635 278 : cplan = GetCachedPlan(entry->plansource, paramLI,
636 : CurrentResourceOwner, pstate->p_queryEnv);
637 :
638 278 : INSTR_TIME_SET_CURRENT(planduration);
639 278 : INSTR_TIME_SUBTRACT(planduration, planstart);
640 :
641 278 : if (es->memory)
642 : {
643 4 : MemoryContextSwitchTo(saved_ctx);
644 4 : MemoryContextMemConsumed(planner_ctx, &mem_counters);
645 : }
646 :
647 : /* calc differences of buffer counters. */
648 278 : if (es->buffers)
649 : {
650 0 : memset(&bufusage, 0, sizeof(BufferUsage));
651 0 : BufferUsageAccumDiff(&bufusage, &pgBufferUsage, &bufusage_start);
652 : }
653 :
654 278 : plan_list = cplan->stmt_list;
655 :
656 : /* Explain each query */
657 556 : foreach(p, plan_list)
658 : {
659 278 : PlannedStmt *pstmt = lfirst_node(PlannedStmt, p);
660 :
661 278 : if (pstmt->commandType != CMD_UTILITY)
662 556 : ExplainOnePlan(pstmt, into, es, query_string, paramLI, pstate->p_queryEnv,
663 278 : &planduration, (es->buffers ? &bufusage : NULL),
664 278 : es->memory ? &mem_counters : NULL);
665 : else
666 0 : ExplainOneUtility(pstmt->utilityStmt, into, es, pstate, paramLI);
667 :
668 : /* No need for CommandCounterIncrement, as ExplainOnePlan did it */
669 :
670 : /* Separate plans with an appropriate separator */
671 278 : if (lnext(plan_list, p) != NULL)
672 0 : ExplainSeparatePlans(es);
673 : }
674 :
675 278 : if (estate)
676 190 : FreeExecutorState(estate);
677 :
678 278 : ReleaseCachedPlan(cplan, CurrentResourceOwner);
679 278 : }
680 :
681 : /*
682 : * This set returning function reads all the prepared statements and
683 : * returns a set of (name, statement, prepare_time, param_types, from_sql,
684 : * generic_plans, custom_plans).
685 : */
686 : Datum
687 68 : pg_prepared_statement(PG_FUNCTION_ARGS)
688 : {
689 68 : ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
690 :
691 : /*
692 : * We put all the tuples into a tuplestore in one scan of the hashtable.
693 : * This avoids any issue of the hashtable possibly changing between calls.
694 : */
695 68 : InitMaterializedSRF(fcinfo, 0);
696 :
697 : /* hash table might be uninitialized */
698 68 : if (prepared_queries)
699 : {
700 : HASH_SEQ_STATUS hash_seq;
701 : PreparedStatement *prep_stmt;
702 :
703 60 : hash_seq_init(&hash_seq, prepared_queries);
704 256 : while ((prep_stmt = hash_seq_search(&hash_seq)) != NULL)
705 : {
706 : TupleDesc result_desc;
707 : Datum values[8];
708 196 : bool nulls[8] = {0};
709 :
710 196 : result_desc = prep_stmt->plansource->resultDesc;
711 :
712 196 : values[0] = CStringGetTextDatum(prep_stmt->stmt_name);
713 196 : values[1] = CStringGetTextDatum(prep_stmt->plansource->query_string);
714 196 : values[2] = TimestampTzGetDatum(prep_stmt->prepare_time);
715 392 : values[3] = build_regtype_array(prep_stmt->plansource->param_types,
716 196 : prep_stmt->plansource->num_params);
717 196 : if (result_desc)
718 : {
719 : Oid *result_types;
720 :
721 192 : result_types = palloc_array(Oid, result_desc->natts);
722 652 : for (int i = 0; i < result_desc->natts; i++)
723 460 : result_types[i] = TupleDescAttr(result_desc, i)->atttypid;
724 192 : values[4] = build_regtype_array(result_types, result_desc->natts);
725 : }
726 : else
727 : {
728 : /* no result descriptor (for example, DML statement) */
729 4 : nulls[4] = true;
730 : }
731 196 : values[5] = BoolGetDatum(prep_stmt->from_sql);
732 196 : values[6] = Int64GetDatumFast(prep_stmt->plansource->num_generic_plans);
733 196 : values[7] = Int64GetDatumFast(prep_stmt->plansource->num_custom_plans);
734 :
735 196 : tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc,
736 : values, nulls);
737 : }
738 : }
739 :
740 68 : return (Datum) 0;
741 : }
742 :
743 : /*
744 : * This utility function takes a C array of Oids, and returns a Datum
745 : * pointing to a one-dimensional Postgres array of regtypes. An empty
746 : * array is returned as a zero-element array, not NULL.
747 : */
748 : static Datum
749 388 : build_regtype_array(Oid *param_types, int num_params)
750 : {
751 : Datum *tmp_ary;
752 : ArrayType *result;
753 : int i;
754 :
755 388 : tmp_ary = palloc_array(Datum, num_params);
756 :
757 956 : for (i = 0; i < num_params; i++)
758 568 : tmp_ary[i] = ObjectIdGetDatum(param_types[i]);
759 :
760 388 : result = construct_array_builtin(tmp_ary, num_params, REGTYPEOID);
761 388 : return PointerGetDatum(result);
762 : }
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