PostgreSQL Source Code  git master
prepare.c File Reference
#include "postgres.h"
#include <limits.h>
#include "access/xact.h"
#include "catalog/pg_type.h"
#include "commands/createas.h"
#include "commands/prepare.h"
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
#include "parser/analyze.h"
#include "parser/parse_coerce.h"
#include "parser/parse_collate.h"
#include "parser/parse_expr.h"
#include "parser/parse_type.h"
#include "rewrite/rewriteHandler.h"
#include "tcop/pquery.h"
#include "tcop/utility.h"
#include "utils/builtins.h"
#include "utils/snapmgr.h"
#include "utils/timestamp.h"
Include dependency graph for prepare.c:

Go to the source code of this file.

Functions

static void InitQueryHashTable (void)
 
static ParamListInfo EvaluateParams (ParseState *pstate, PreparedStatement *pstmt, List *params, EState *estate)
 
static Datum build_regtype_array (Oid *param_types, int num_params)
 
void PrepareQuery (ParseState *pstate, PrepareStmt *stmt, int stmt_location, int stmt_len)
 
void ExecuteQuery (ParseState *pstate, ExecuteStmt *stmt, IntoClause *intoClause, ParamListInfo params, DestReceiver *dest, QueryCompletion *qc)
 
void StorePreparedStatement (const char *stmt_name, CachedPlanSource *plansource, bool from_sql)
 
PreparedStatementFetchPreparedStatement (const char *stmt_name, bool throwError)
 
TupleDesc FetchPreparedStatementResultDesc (PreparedStatement *stmt)
 
ListFetchPreparedStatementTargetList (PreparedStatement *stmt)
 
void DeallocateQuery (DeallocateStmt *stmt)
 
void DropPreparedStatement (const char *stmt_name, bool showError)
 
void DropAllPreparedStatements (void)
 
void ExplainExecuteQuery (ExecuteStmt *execstmt, IntoClause *into, ExplainState *es, const char *queryString, ParamListInfo params, QueryEnvironment *queryEnv)
 
Datum pg_prepared_statement (PG_FUNCTION_ARGS)
 

Variables

static HTABprepared_queries = NULL
 

Function Documentation

◆ build_regtype_array()

static Datum build_regtype_array ( Oid param_types,
int  num_params 
)
static

Definition at line 790 of file prepare.c.

References construct_array(), i, ObjectIdGetDatum, palloc(), and PointerGetDatum.

Referenced by pg_prepared_statement().

791 {
792  Datum *tmp_ary;
793  ArrayType *result;
794  int i;
795 
796  tmp_ary = (Datum *) palloc(num_params * sizeof(Datum));
797 
798  for (i = 0; i < num_params; i++)
799  tmp_ary[i] = ObjectIdGetDatum(param_types[i]);
800 
801  /* XXX: this hardcodes assumptions about the regtype type */
802  result = construct_array(tmp_ary, num_params, REGTYPEOID,
803  4, true, TYPALIGN_INT);
804  return PointerGetDatum(result);
805 }
#define PointerGetDatum(X)
Definition: postgres.h:556
ArrayType * construct_array(Datum *elems, int nelems, Oid elmtype, int elmlen, bool elmbyval, char elmalign)
Definition: arrayfuncs.c:3292
#define ObjectIdGetDatum(X)
Definition: postgres.h:507
uintptr_t Datum
Definition: postgres.h:367
void * palloc(Size size)
Definition: mcxt.c:949
int i

◆ DeallocateQuery()

void DeallocateQuery ( DeallocateStmt stmt)

Definition at line 540 of file prepare.c.

References DropAllPreparedStatements(), DropPreparedStatement(), and DeallocateStmt::name.

Referenced by standard_ProcessUtility().

541 {
542  if (stmt->name)
543  DropPreparedStatement(stmt->name, true);
544  else
546 }
void DropAllPreparedStatements(void)
Definition: prepare.c:575
void DropPreparedStatement(const char *stmt_name, bool showError)
Definition: prepare.c:554

◆ DropAllPreparedStatements()

void DropAllPreparedStatements ( void  )

Definition at line 575 of file prepare.c.

References DropCachedPlan(), HASH_REMOVE, hash_search(), hash_seq_init(), hash_seq_search(), PreparedStatement::plansource, and PreparedStatement::stmt_name.

Referenced by DeallocateQuery(), and DiscardAll().

576 {
577  HASH_SEQ_STATUS seq;
578  PreparedStatement *entry;
579 
580  /* nothing cached */
581  if (!prepared_queries)
582  return;
583 
584  /* walk over cache */
586  while ((entry = hash_seq_search(&seq)) != NULL)
587  {
588  /* Release the plancache entry */
589  DropCachedPlan(entry->plansource);
590 
591  /* Now we can remove the hash table entry */
593  }
594 }
CachedPlanSource * plansource
Definition: prepare.h:31
void * hash_search(HTAB *hashp, const void *keyPtr, HASHACTION action, bool *foundPtr)
Definition: dynahash.c:908
static HTAB * prepared_queries
Definition: prepare.c:46
char stmt_name[NAMEDATALEN]
Definition: prepare.h:30
void * hash_seq_search(HASH_SEQ_STATUS *status)
Definition: dynahash.c:1391
void hash_seq_init(HASH_SEQ_STATUS *status, HTAB *hashp)
Definition: dynahash.c:1381
void DropCachedPlan(CachedPlanSource *plansource)
Definition: plancache.c:496

◆ DropPreparedStatement()

void DropPreparedStatement ( const char *  stmt_name,
bool  showError 
)

Definition at line 554 of file prepare.c.

References DropCachedPlan(), FetchPreparedStatement(), HASH_REMOVE, hash_search(), PreparedStatement::plansource, and PreparedStatement::stmt_name.

Referenced by DeallocateQuery(), and PostgresMain().

555 {
556  PreparedStatement *entry;
557 
558  /* Find the query's hash table entry; raise error if wanted */
559  entry = FetchPreparedStatement(stmt_name, showError);
560 
561  if (entry)
562  {
563  /* Release the plancache entry */
564  DropCachedPlan(entry->plansource);
565 
566  /* Now we can remove the hash table entry */
568  }
569 }
CachedPlanSource * plansource
Definition: prepare.h:31
void * hash_search(HTAB *hashp, const void *keyPtr, HASHACTION action, bool *foundPtr)
Definition: dynahash.c:908
static HTAB * prepared_queries
Definition: prepare.c:46
char stmt_name[NAMEDATALEN]
Definition: prepare.h:30
void DropCachedPlan(CachedPlanSource *plansource)
Definition: plancache.c:496
PreparedStatement * FetchPreparedStatement(const char *stmt_name, bool throwError)
Definition: prepare.c:469

◆ EvaluateParams()

static ParamListInfo EvaluateParams ( ParseState pstate,
PreparedStatement pstmt,
List params,
EState estate 
)
static

Definition at line 314 of file prepare.c.

References assign_expr_collations(), COERCE_IMPLICIT_CAST, coerce_to_target_type(), COERCION_ASSIGNMENT, copyObject, ereport, errcode(), errdetail(), errhint(), errmsg(), ERROR, ExecEvalExprSwitchContext(), ExecPrepareExprList(), EXPR_KIND_EXECUTE_PARAMETER, exprLocation(), exprType(), format_type_be(), GetPerTupleExprContext, i, ParamExternData::isnull, lfirst, list_length(), makeParamList(), CachedPlanSource::num_params, PARAM_FLAG_CONST, CachedPlanSource::param_types, ParamListInfoData::params, parser_errposition(), ParamExternData::pflags, PreparedStatement::plansource, ParamExternData::ptype, PreparedStatement::stmt_name, transformExpr(), and ParamExternData::value.

Referenced by ExecuteQuery(), and ExplainExecuteQuery().

316 {
317  Oid *param_types = pstmt->plansource->param_types;
318  int num_params = pstmt->plansource->num_params;
319  int nparams = list_length(params);
320  ParamListInfo paramLI;
321  List *exprstates;
322  ListCell *l;
323  int i;
324 
325  if (nparams != num_params)
326  ereport(ERROR,
327  (errcode(ERRCODE_SYNTAX_ERROR),
328  errmsg("wrong number of parameters for prepared statement \"%s\"",
329  pstmt->stmt_name),
330  errdetail("Expected %d parameters but got %d.",
331  num_params, nparams)));
332 
333  /* Quick exit if no parameters */
334  if (num_params == 0)
335  return NULL;
336 
337  /*
338  * We have to run parse analysis for the expressions. Since the parser is
339  * not cool about scribbling on its input, copy first.
340  */
341  params = copyObject(params);
342 
343  i = 0;
344  foreach(l, params)
345  {
346  Node *expr = lfirst(l);
347  Oid expected_type_id = param_types[i];
348  Oid given_type_id;
349 
350  expr = transformExpr(pstate, expr, EXPR_KIND_EXECUTE_PARAMETER);
351 
352  given_type_id = exprType(expr);
353 
354  expr = coerce_to_target_type(pstate, expr, given_type_id,
355  expected_type_id, -1,
358  -1);
359 
360  if (expr == NULL)
361  ereport(ERROR,
362  (errcode(ERRCODE_DATATYPE_MISMATCH),
363  errmsg("parameter $%d of type %s cannot be coerced to the expected type %s",
364  i + 1,
365  format_type_be(given_type_id),
366  format_type_be(expected_type_id)),
367  errhint("You will need to rewrite or cast the expression."),
368  parser_errposition(pstate, exprLocation(lfirst(l)))));
369 
370  /* Take care of collations in the finished expression. */
371  assign_expr_collations(pstate, expr);
372 
373  lfirst(l) = expr;
374  i++;
375  }
376 
377  /* Prepare the expressions for execution */
378  exprstates = ExecPrepareExprList(params, estate);
379 
380  paramLI = makeParamList(num_params);
381 
382  i = 0;
383  foreach(l, exprstates)
384  {
385  ExprState *n = (ExprState *) lfirst(l);
386  ParamExternData *prm = &paramLI->params[i];
387 
388  prm->ptype = param_types[i];
389  prm->pflags = PARAM_FLAG_CONST;
391  GetPerTupleExprContext(estate),
392  &prm->isnull);
393 
394  i++;
395  }
396 
397  return paramLI;
398 }
ParamExternData params[FLEXIBLE_ARRAY_MEMBER]
Definition: params.h:125
Datum value
Definition: params.h:92
static Datum ExecEvalExprSwitchContext(ExprState *state, ExprContext *econtext, bool *isNull)
Definition: executor.h:305
int errhint(const char *fmt,...)
Definition: elog.c:1071
int exprLocation(const Node *expr)
Definition: nodeFuncs.c:1191
CachedPlanSource * plansource
Definition: prepare.h:31
Node * transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind)
Definition: parse_expr.c:145
Definition: nodes.h:529
int errcode(int sqlerrcode)
Definition: elog.c:610
char * format_type_be(Oid type_oid)
Definition: format_type.c:327
unsigned int Oid
Definition: postgres_ext.h:31
ParamListInfo makeParamList(int numParams)
Definition: params.c:35
void assign_expr_collations(ParseState *pstate, Node *expr)
#define GetPerTupleExprContext(estate)
Definition: executor.h:507
char stmt_name[NAMEDATALEN]
Definition: prepare.h:30
#define ERROR
Definition: elog.h:43
Node * coerce_to_target_type(ParseState *pstate, Node *expr, Oid exprtype, Oid targettype, int32 targettypmod, CoercionContext ccontext, CoercionForm cformat, int location)
Definition: parse_coerce.c:77
int errdetail(const char *fmt,...)
Definition: elog.c:957
List * ExecPrepareExprList(List *nodes, EState *estate)
Definition: execExpr.c:566
#define ereport(elevel,...)
Definition: elog.h:144
#define lfirst(lc)
Definition: pg_list.h:190
uint16 pflags
Definition: params.h:94
Oid exprType(const Node *expr)
Definition: nodeFuncs.c:41
static int list_length(const List *l)
Definition: pg_list.h:169
int parser_errposition(ParseState *pstate, int location)
Definition: parse_node.c:110
int errmsg(const char *fmt,...)
Definition: elog.c:824
int i
#define copyObject(obj)
Definition: nodes.h:645
Definition: pg_list.h:50
bool isnull
Definition: params.h:93
#define PARAM_FLAG_CONST
Definition: params.h:88

◆ ExecuteQuery()

void ExecuteQuery ( ParseState pstate,
ExecuteStmt stmt,
IntoClause intoClause,
ParamListInfo  params,
DestReceiver dest,
QueryCompletion qc 
)

Definition at line 187 of file prepare.c.

References CMD_SELECT, CachedPlanSource::commandTag, PlannedStmt::commandType, CreateExecutorState(), CreateNewPortal(), elog, ereport, errcode(), errmsg(), ERROR, EState::es_param_list_info, EvaluateParams(), FETCH_ALL, FetchPreparedStatement(), CachedPlanSource::fixed_result, FreeExecutorState(), GetActiveSnapshot(), GetCachedPlan(), GetIntoRelEFlags(), linitial_node, list_length(), MemoryContextStrdup(), ExecuteStmt::name, CachedPlanSource::num_params, ExecuteStmt::params, PreparedStatement::plansource, PortalData::portalContext, PortalDefineQuery(), PortalDrop(), PortalRun(), PortalStart(), CachedPlanSource::query_string, IntoClause::skipData, CachedPlan::stmt_list, and PortalData::visible.

Referenced by ExecCreateTableAs(), and standard_ProcessUtility().

191 {
192  PreparedStatement *entry;
193  CachedPlan *cplan;
194  List *plan_list;
195  ParamListInfo paramLI = NULL;
196  EState *estate = NULL;
197  Portal portal;
198  char *query_string;
199  int eflags;
200  long count;
201 
202  /* Look it up in the hash table */
203  entry = FetchPreparedStatement(stmt->name, true);
204 
205  /* Shouldn't find a non-fixed-result cached plan */
206  if (!entry->plansource->fixed_result)
207  elog(ERROR, "EXECUTE does not support variable-result cached plans");
208 
209  /* Evaluate parameters, if any */
210  if (entry->plansource->num_params > 0)
211  {
212  /*
213  * Need an EState to evaluate parameters; must not delete it till end
214  * of query, in case parameters are pass-by-reference. Note that the
215  * passed-in "params" could possibly be referenced in the parameter
216  * expressions.
217  */
218  estate = CreateExecutorState();
219  estate->es_param_list_info = params;
220  paramLI = EvaluateParams(pstate, entry, stmt->params, estate);
221  }
222 
223  /* Create a new portal to run the query in */
224  portal = CreateNewPortal();
225  /* Don't display the portal in pg_cursors, it is for internal use only */
226  portal->visible = false;
227 
228  /* Copy the plan's saved query string into the portal's memory */
229  query_string = MemoryContextStrdup(portal->portalContext,
230  entry->plansource->query_string);
231 
232  /* Replan if needed, and increment plan refcount for portal */
233  cplan = GetCachedPlan(entry->plansource, paramLI, false, NULL);
234  plan_list = cplan->stmt_list;
235 
236  /*
237  * For CREATE TABLE ... AS EXECUTE, we must verify that the prepared
238  * statement is one that produces tuples. Currently we insist that it be
239  * a plain old SELECT. In future we might consider supporting other
240  * things such as INSERT ... RETURNING, but there are a couple of issues
241  * to be settled first, notably how WITH NO DATA should be handled in such
242  * a case (do we really want to suppress execution?) and how to pass down
243  * the OID-determining eflags (PortalStart won't handle them in such a
244  * case, and for that matter it's not clear the executor will either).
245  *
246  * For CREATE TABLE ... AS EXECUTE, we also have to ensure that the proper
247  * eflags and fetch count are passed to PortalStart/PortalRun.
248  */
249  if (intoClause)
250  {
251  PlannedStmt *pstmt;
252 
253  if (list_length(plan_list) != 1)
254  ereport(ERROR,
255  (errcode(ERRCODE_WRONG_OBJECT_TYPE),
256  errmsg("prepared statement is not a SELECT")));
257  pstmt = linitial_node(PlannedStmt, plan_list);
258  if (pstmt->commandType != CMD_SELECT)
259  ereport(ERROR,
260  (errcode(ERRCODE_WRONG_OBJECT_TYPE),
261  errmsg("prepared statement is not a SELECT")));
262 
263  /* Set appropriate eflags */
264  eflags = GetIntoRelEFlags(intoClause);
265 
266  /* And tell PortalRun whether to run to completion or not */
267  if (intoClause->skipData)
268  count = 0;
269  else
270  count = FETCH_ALL;
271  }
272  else
273  {
274  /* Plain old EXECUTE */
275  eflags = 0;
276  count = FETCH_ALL;
277  }
278 
279  PortalDefineQuery(portal,
280  NULL,
281  query_string,
282  entry->plansource->commandTag,
283  plan_list,
284  cplan);
285 
286  /*
287  * Run the portal as appropriate.
288  */
289  PortalStart(portal, paramLI, eflags, GetActiveSnapshot());
290 
291  (void) PortalRun(portal, count, false, true, dest, dest, qc);
292 
293  PortalDrop(portal, false);
294 
295  if (estate)
296  FreeExecutorState(estate);
297 
298  /* No need to pfree other memory, MemoryContext will be reset */
299 }
CachedPlan * GetCachedPlan(CachedPlanSource *plansource, ParamListInfo boundParams, bool useResOwner, QueryEnvironment *queryEnv)
Definition: plancache.c:1139
Portal CreateNewPortal(void)
Definition: portalmem.c:234
void PortalStart(Portal portal, ParamListInfo params, int eflags, Snapshot snapshot)
Definition: pquery.c:430
bool visible
Definition: portal.h:196
CachedPlanSource * plansource
Definition: prepare.h:31
Snapshot GetActiveSnapshot(void)
Definition: snapmgr.c:841
static ParamListInfo EvaluateParams(ParseState *pstate, PreparedStatement *pstmt, List *params, EState *estate)
Definition: prepare.c:314
int errcode(int sqlerrcode)
Definition: elog.c:610
bool skipData
Definition: primnodes.h:119
void PortalDefineQuery(Portal portal, const char *prepStmtName, const char *sourceText, CommandTag commandTag, List *stmts, CachedPlan *cplan)
Definition: portalmem.c:281
#define linitial_node(type, l)
Definition: pg_list.h:198
MemoryContext portalContext
Definition: portal.h:120
bool PortalRun(Portal portal, long count, bool isTopLevel, bool run_once, DestReceiver *dest, DestReceiver *altdest, QueryCompletion *qc)
Definition: pquery.c:672
void FreeExecutorState(EState *estate)
Definition: execUtils.c:191
int GetIntoRelEFlags(IntoClause *intoClause)
Definition: createas.c:393
#define ERROR
Definition: elog.h:43
EState * CreateExecutorState(void)
Definition: execUtils.c:89
CmdType commandType
Definition: plannodes.h:46
#define ereport(elevel,...)
Definition: elog.h:144
const char * query_string
Definition: plancache.h:100
CommandTag commandTag
Definition: plancache.h:101
static int list_length(const List *l)
Definition: pg_list.h:169
int errmsg(const char *fmt,...)
Definition: elog.c:824
void PortalDrop(Portal portal, bool isTopCommit)
Definition: portalmem.c:467
char * MemoryContextStrdup(MemoryContext context, const char *string)
Definition: mcxt.c:1173
#define elog(elevel,...)
Definition: elog.h:214
char * name
Definition: parsenodes.h:3438
ParamListInfo es_param_list_info
Definition: execnodes.h:549
List * params
Definition: parsenodes.h:3439
List * stmt_list
Definition: plancache.h:149
PreparedStatement * FetchPreparedStatement(const char *stmt_name, bool throwError)
Definition: prepare.c:469
Definition: pg_list.h:50
#define FETCH_ALL
Definition: parsenodes.h:2750

◆ ExplainExecuteQuery()

void ExplainExecuteQuery ( ExecuteStmt execstmt,
IntoClause into,
ExplainState es,
const char *  queryString,
ParamListInfo  params,
QueryEnvironment queryEnv 
)

Definition at line 606 of file prepare.c.

References ExplainState::buffers, BufferUsageAccumDiff(), CMD_UTILITY, PlannedStmt::commandType, CreateExecutorState(), elog, ERROR, EState::es_param_list_info, EvaluateParams(), ExplainOnePlan(), ExplainOneUtility(), ExplainSeparatePlans(), FetchPreparedStatement(), CachedPlanSource::fixed_result, FreeExecutorState(), GetCachedPlan(), INSTR_TIME_SET_CURRENT, INSTR_TIME_SUBTRACT, lfirst_node, lnext(), make_parsestate(), ExecuteStmt::name, CachedPlanSource::num_params, ParseState::p_sourcetext, ExecuteStmt::params, pgBufferUsage, PreparedStatement::plansource, CachedPlanSource::query_string, ReleaseCachedPlan(), CachedPlan::stmt_list, and PlannedStmt::utilityStmt.

Referenced by ExplainOneUtility().

609 {
610  PreparedStatement *entry;
611  const char *query_string;
612  CachedPlan *cplan;
613  List *plan_list;
614  ListCell *p;
615  ParamListInfo paramLI = NULL;
616  EState *estate = NULL;
617  instr_time planstart;
618  instr_time planduration;
619  BufferUsage bufusage_start,
620  bufusage;
621 
622  if (es->buffers)
623  bufusage_start = pgBufferUsage;
624  INSTR_TIME_SET_CURRENT(planstart);
625 
626  /* Look it up in the hash table */
627  entry = FetchPreparedStatement(execstmt->name, true);
628 
629  /* Shouldn't find a non-fixed-result cached plan */
630  if (!entry->plansource->fixed_result)
631  elog(ERROR, "EXPLAIN EXECUTE does not support variable-result cached plans");
632 
633  query_string = entry->plansource->query_string;
634 
635  /* Evaluate parameters, if any */
636  if (entry->plansource->num_params)
637  {
638  ParseState *pstate;
639 
640  pstate = make_parsestate(NULL);
641  pstate->p_sourcetext = queryString;
642 
643  /*
644  * Need an EState to evaluate parameters; must not delete it till end
645  * of query, in case parameters are pass-by-reference. Note that the
646  * passed-in "params" could possibly be referenced in the parameter
647  * expressions.
648  */
649  estate = CreateExecutorState();
650  estate->es_param_list_info = params;
651 
652  paramLI = EvaluateParams(pstate, entry, execstmt->params, estate);
653  }
654 
655  /* Replan if needed, and acquire a transient refcount */
656  cplan = GetCachedPlan(entry->plansource, paramLI, true, queryEnv);
657 
658  INSTR_TIME_SET_CURRENT(planduration);
659  INSTR_TIME_SUBTRACT(planduration, planstart);
660 
661  /* calc differences of buffer counters. */
662  if (es->buffers)
663  {
664  memset(&bufusage, 0, sizeof(BufferUsage));
665  BufferUsageAccumDiff(&bufusage, &pgBufferUsage, &bufusage_start);
666  }
667 
668  plan_list = cplan->stmt_list;
669 
670  /* Explain each query */
671  foreach(p, plan_list)
672  {
673  PlannedStmt *pstmt = lfirst_node(PlannedStmt, p);
674 
675  if (pstmt->commandType != CMD_UTILITY)
676  ExplainOnePlan(pstmt, into, es, query_string, paramLI, queryEnv,
677  &planduration, (es->buffers ? &bufusage : NULL));
678  else
679  ExplainOneUtility(pstmt->utilityStmt, into, es, query_string,
680  paramLI, queryEnv);
681 
682  /* No need for CommandCounterIncrement, as ExplainOnePlan did it */
683 
684  /* Separate plans with an appropriate separator */
685  if (lnext(plan_list, p) != NULL)
687  }
688 
689  if (estate)
690  FreeExecutorState(estate);
691 
692  ReleaseCachedPlan(cplan, true);
693 }
CachedPlan * GetCachedPlan(CachedPlanSource *plansource, ParamListInfo boundParams, bool useResOwner, QueryEnvironment *queryEnv)
Definition: plancache.c:1139
void ExplainSeparatePlans(ExplainState *es)
Definition: explain.c:4518
static ListCell * lnext(const List *l, const ListCell *c)
Definition: pg_list.h:321
CachedPlanSource * plansource
Definition: prepare.h:31
struct timeval instr_time
Definition: instr_time.h:150
static ParamListInfo EvaluateParams(ParseState *pstate, PreparedStatement *pstmt, List *params, EState *estate)
Definition: prepare.c:314
void BufferUsageAccumDiff(BufferUsage *dst, const BufferUsage *add, const BufferUsage *sub)
Definition: instrument.c:225
ParseState * make_parsestate(ParseState *parentParseState)
Definition: parse_node.c:43
void FreeExecutorState(EState *estate)
Definition: execUtils.c:191
#define ERROR
Definition: elog.h:43
#define INSTR_TIME_SUBTRACT(x, y)
Definition: instr_time.h:170
#define lfirst_node(type, lc)
Definition: pg_list.h:193
Node * utilityStmt
Definition: plannodes.h:92
void ReleaseCachedPlan(CachedPlan *plan, bool useResOwner)
Definition: plancache.c:1260
const char * p_sourcetext
Definition: parse_node.h:179
EState * CreateExecutorState(void)
Definition: execUtils.c:89
CmdType commandType
Definition: plannodes.h:46
void ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, ExplainState *es, const char *queryString, ParamListInfo params, QueryEnvironment *queryEnv, const instr_time *planduration, const BufferUsage *bufusage)
Definition: explain.c:500
const char * query_string
Definition: plancache.h:100
#define INSTR_TIME_SET_CURRENT(t)
Definition: instr_time.h:156
#define elog(elevel,...)
Definition: elog.h:214
char * name
Definition: parsenodes.h:3438
bool buffers
Definition: explain.h:44
ParamListInfo es_param_list_info
Definition: execnodes.h:549
List * params
Definition: parsenodes.h:3439
List * stmt_list
Definition: plancache.h:149
PreparedStatement * FetchPreparedStatement(const char *stmt_name, bool throwError)
Definition: prepare.c:469
Definition: pg_list.h:50
void ExplainOneUtility(Node *utilityStmt, IntoClause *into, ExplainState *es, const char *queryString, ParamListInfo params, QueryEnvironment *queryEnv)
Definition: explain.c:425
BufferUsage pgBufferUsage
Definition: instrument.c:20

◆ FetchPreparedStatement()

PreparedStatement* FetchPreparedStatement ( const char *  stmt_name,
bool  throwError 
)

Definition at line 469 of file prepare.c.

References ereport, errcode(), errmsg(), ERROR, HASH_FIND, and hash_search().

Referenced by DropPreparedStatement(), errdetail_execute(), exec_bind_message(), exec_describe_statement_message(), ExecuteQuery(), ExplainExecuteQuery(), FetchStatementTargetList(), GetCommandLogLevel(), UtilityReturnsTuples(), and UtilityTupleDescriptor().

470 {
471  PreparedStatement *entry;
472 
473  /*
474  * If the hash table hasn't been initialized, it can't be storing
475  * anything, therefore it couldn't possibly store our plan.
476  */
477  if (prepared_queries)
479  stmt_name,
480  HASH_FIND,
481  NULL);
482  else
483  entry = NULL;
484 
485  if (!entry && throwError)
486  ereport(ERROR,
487  (errcode(ERRCODE_UNDEFINED_PSTATEMENT),
488  errmsg("prepared statement \"%s\" does not exist",
489  stmt_name)));
490 
491  return entry;
492 }
int errcode(int sqlerrcode)
Definition: elog.c:610
void * hash_search(HTAB *hashp, const void *keyPtr, HASHACTION action, bool *foundPtr)
Definition: dynahash.c:908
static HTAB * prepared_queries
Definition: prepare.c:46
#define ERROR
Definition: elog.h:43
#define ereport(elevel,...)
Definition: elog.h:144
int errmsg(const char *fmt,...)
Definition: elog.c:824

◆ FetchPreparedStatementResultDesc()

TupleDesc FetchPreparedStatementResultDesc ( PreparedStatement stmt)

Definition at line 501 of file prepare.c.

References Assert, CreateTupleDescCopy(), CachedPlanSource::fixed_result, PreparedStatement::plansource, and CachedPlanSource::resultDesc.

Referenced by UtilityTupleDescriptor().

502 {
503  /*
504  * Since we don't allow prepared statements' result tupdescs to change,
505  * there's no need to worry about revalidating the cached plan here.
506  */
508  if (stmt->plansource->resultDesc)
510  else
511  return NULL;
512 }
TupleDesc CreateTupleDescCopy(TupleDesc tupdesc)
Definition: tupdesc.c:110
CachedPlanSource * plansource
Definition: prepare.h:31
TupleDesc resultDesc
Definition: plancache.h:108
#define Assert(condition)
Definition: c.h:738

◆ FetchPreparedStatementTargetList()

List* FetchPreparedStatementTargetList ( PreparedStatement stmt)

Definition at line 524 of file prepare.c.

References CachedPlanGetTargetList(), copyObject, and PreparedStatement::plansource.

Referenced by FetchStatementTargetList().

525 {
526  List *tlist;
527 
528  /* Get the plan's primary targetlist */
529  tlist = CachedPlanGetTargetList(stmt->plansource, NULL);
530 
531  /* Copy into caller's context in case plan gets invalidated */
532  return copyObject(tlist);
533 }
CachedPlanSource * plansource
Definition: prepare.h:31
List * CachedPlanGetTargetList(CachedPlanSource *plansource, QueryEnvironment *queryEnv)
Definition: plancache.c:1606
#define copyObject(obj)
Definition: nodes.h:645
Definition: pg_list.h:50

◆ InitQueryHashTable()

static void InitQueryHashTable ( void  )
static

Definition at line 405 of file prepare.c.

References HASHCTL::entrysize, hash_create(), HASH_ELEM, HASHCTL::keysize, MemSet, and NAMEDATALEN.

Referenced by StorePreparedStatement().

406 {
407  HASHCTL hash_ctl;
408 
409  MemSet(&hash_ctl, 0, sizeof(hash_ctl));
410 
411  hash_ctl.keysize = NAMEDATALEN;
412  hash_ctl.entrysize = sizeof(PreparedStatement);
413 
414  prepared_queries = hash_create("Prepared Queries",
415  32,
416  &hash_ctl,
417  HASH_ELEM);
418 }
#define HASH_ELEM
Definition: hsearch.h:87
Size entrysize
Definition: hsearch.h:73
#define MemSet(start, val, len)
Definition: c.h:971
#define NAMEDATALEN
static HTAB * prepared_queries
Definition: prepare.c:46
HTAB * hash_create(const char *tabname, long nelem, HASHCTL *info, int flags)
Definition: dynahash.c:318
Size keysize
Definition: hsearch.h:72

◆ pg_prepared_statement()

Datum pg_prepared_statement ( PG_FUNCTION_ARGS  )

Definition at line 700 of file prepare.c.

References ReturnSetInfo::allowedModes, BoolGetDatum, build_regtype_array(), CreateTemplateTupleDesc(), CStringGetTextDatum, ReturnSetInfo::econtext, ExprContext::ecxt_per_query_memory, ereport, errcode(), errmsg(), ERROR, PreparedStatement::from_sql, hash_seq_init(), hash_seq_search(), IsA, MemoryContextSwitchTo(), MemSet, CachedPlanSource::num_params, CachedPlanSource::param_types, PreparedStatement::plansource, PreparedStatement::prepare_time, CachedPlanSource::query_string, ReturnSetInfo::returnMode, ReturnSetInfo::setDesc, ReturnSetInfo::setResult, SFRM_Materialize, SFRM_Materialize_Random, PreparedStatement::stmt_name, TimestampTzGetDatum, TupleDescInitEntry(), tuplestore_begin_heap(), tuplestore_donestoring, tuplestore_putvalues(), values, and work_mem.

701 {
702  ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
703  TupleDesc tupdesc;
704  Tuplestorestate *tupstore;
705  MemoryContext per_query_ctx;
706  MemoryContext oldcontext;
707 
708  /* check to see if caller supports us returning a tuplestore */
709  if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
710  ereport(ERROR,
711  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
712  errmsg("set-valued function called in context that cannot accept a set")));
713  if (!(rsinfo->allowedModes & SFRM_Materialize))
714  ereport(ERROR,
715  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
716  errmsg("materialize mode required, but it is not allowed in this context")));
717 
718  /* need to build tuplestore in query context */
719  per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
720  oldcontext = MemoryContextSwitchTo(per_query_ctx);
721 
722  /*
723  * build tupdesc for result tuples. This must match the definition of the
724  * pg_prepared_statements view in system_views.sql
725  */
726  tupdesc = CreateTemplateTupleDesc(5);
727  TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
728  TEXTOID, -1, 0);
729  TupleDescInitEntry(tupdesc, (AttrNumber) 2, "statement",
730  TEXTOID, -1, 0);
731  TupleDescInitEntry(tupdesc, (AttrNumber) 3, "prepare_time",
732  TIMESTAMPTZOID, -1, 0);
733  TupleDescInitEntry(tupdesc, (AttrNumber) 4, "parameter_types",
734  REGTYPEARRAYOID, -1, 0);
735  TupleDescInitEntry(tupdesc, (AttrNumber) 5, "from_sql",
736  BOOLOID, -1, 0);
737 
738  /*
739  * We put all the tuples into a tuplestore in one scan of the hashtable.
740  * This avoids any issue of the hashtable possibly changing between calls.
741  */
742  tupstore =
744  false, work_mem);
745 
746  /* generate junk in short-term context */
747  MemoryContextSwitchTo(oldcontext);
748 
749  /* hash table might be uninitialized */
750  if (prepared_queries)
751  {
752  HASH_SEQ_STATUS hash_seq;
753  PreparedStatement *prep_stmt;
754 
755  hash_seq_init(&hash_seq, prepared_queries);
756  while ((prep_stmt = hash_seq_search(&hash_seq)) != NULL)
757  {
758  Datum values[5];
759  bool nulls[5];
760 
761  MemSet(nulls, 0, sizeof(nulls));
762 
763  values[0] = CStringGetTextDatum(prep_stmt->stmt_name);
764  values[1] = CStringGetTextDatum(prep_stmt->plansource->query_string);
765  values[2] = TimestampTzGetDatum(prep_stmt->prepare_time);
766  values[3] = build_regtype_array(prep_stmt->plansource->param_types,
767  prep_stmt->plansource->num_params);
768  values[4] = BoolGetDatum(prep_stmt->from_sql);
769 
770  tuplestore_putvalues(tupstore, tupdesc, values, nulls);
771  }
772  }
773 
774  /* clean up and return the tuplestore */
775  tuplestore_donestoring(tupstore);
776 
777  rsinfo->returnMode = SFRM_Materialize;
778  rsinfo->setResult = tupstore;
779  rsinfo->setDesc = tupdesc;
780 
781  return (Datum) 0;
782 }
void tuplestore_putvalues(Tuplestorestate *state, TupleDesc tdesc, Datum *values, bool *isnull)
Definition: tuplestore.c:750
#define IsA(nodeptr, _type_)
Definition: nodes.h:580
TupleDesc CreateTemplateTupleDesc(int natts)
Definition: tupdesc.c:44
CachedPlanSource * plansource
Definition: prepare.h:31
#define tuplestore_donestoring(state)
Definition: tuplestore.h:60
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
int errcode(int sqlerrcode)
Definition: elog.c:610
#define MemSet(start, val, len)
Definition: c.h:971
static HTAB * prepared_queries
Definition: prepare.c:46
char stmt_name[NAMEDATALEN]
Definition: prepare.h:30
#define ERROR
Definition: elog.h:43
#define TimestampTzGetDatum(X)
Definition: timestamp.h:32
void TupleDescInitEntry(TupleDesc desc, AttrNumber attributeNumber, const char *attributeName, Oid oidtypeid, int32 typmod, int attdim)
Definition: tupdesc.c:603
static Datum build_regtype_array(Oid *param_types, int num_params)
Definition: prepare.c:790
Tuplestorestate * tuplestore_begin_heap(bool randomAccess, bool interXact, int maxKBytes)
Definition: tuplestore.c:318
uintptr_t Datum
Definition: postgres.h:367
int work_mem
Definition: globals.c:121
#define BoolGetDatum(X)
Definition: postgres.h:402
#define ereport(elevel,...)
Definition: elog.h:144
int allowedModes
Definition: execnodes.h:305
TimestampTz prepare_time
Definition: prepare.h:33
SetFunctionReturnMode returnMode
Definition: execnodes.h:307
const char * query_string
Definition: plancache.h:100
void * hash_seq_search(HASH_SEQ_STATUS *status)
Definition: dynahash.c:1391
MemoryContext ecxt_per_query_memory
Definition: execnodes.h:233
void hash_seq_init(HASH_SEQ_STATUS *status, HTAB *hashp)
Definition: dynahash.c:1381
Tuplestorestate * setResult
Definition: execnodes.h:310
static Datum values[MAXATTR]
Definition: bootstrap.c:167
ExprContext * econtext
Definition: execnodes.h:303
TupleDesc setDesc
Definition: execnodes.h:311
int errmsg(const char *fmt,...)
Definition: elog.c:824
#define CStringGetTextDatum(s)
Definition: builtins.h:87
int16 AttrNumber
Definition: attnum.h:21

◆ PrepareQuery()

void PrepareQuery ( ParseState pstate,
PrepareStmt stmt,
int  stmt_location,
int  stmt_len 
)

Definition at line 58 of file prepare.c.

References PrepareStmt::argtypes, CMD_DELETE, CMD_INSERT, CMD_SELECT, CMD_UPDATE, Query::commandType, CompleteCachedPlan(), copyObject, CreateCachedPlan(), CreateCommandTag(), CURSOR_OPT_PARALLEL_OK, ereport, errcode(), errmsg(), ERROR, i, InvalidOid, lfirst, list_length(), makeNode, PrepareStmt::name, ParseState::p_sourcetext, palloc(), parse_analyze_varparams(), PrepareStmt::query, QueryRewrite(), RawStmt::stmt, RawStmt::stmt_len, RawStmt::stmt_location, StorePreparedStatement(), and typenameTypeId().

Referenced by standard_ProcessUtility().

60 {
61  RawStmt *rawstmt;
62  CachedPlanSource *plansource;
63  Oid *argtypes = NULL;
64  int nargs;
65  Query *query;
66  List *query_list;
67  int i;
68 
69  /*
70  * Disallow empty-string statement name (conflicts with protocol-level
71  * unnamed statement).
72  */
73  if (!stmt->name || stmt->name[0] == '\0')
74  ereport(ERROR,
75  (errcode(ERRCODE_INVALID_PSTATEMENT_DEFINITION),
76  errmsg("invalid statement name: must not be empty")));
77 
78  /*
79  * Need to wrap the contained statement in a RawStmt node to pass it to
80  * parse analysis.
81  *
82  * Because parse analysis scribbles on the raw querytree, we must make a
83  * copy to ensure we don't modify the passed-in tree. FIXME someday.
84  */
85  rawstmt = makeNode(RawStmt);
86  rawstmt->stmt = (Node *) copyObject(stmt->query);
87  rawstmt->stmt_location = stmt_location;
88  rawstmt->stmt_len = stmt_len;
89 
90  /*
91  * Create the CachedPlanSource before we do parse analysis, since it needs
92  * to see the unmodified raw parse tree.
93  */
94  plansource = CreateCachedPlan(rawstmt, pstate->p_sourcetext,
95  CreateCommandTag(stmt->query));
96 
97  /* Transform list of TypeNames to array of type OIDs */
98  nargs = list_length(stmt->argtypes);
99 
100  if (nargs)
101  {
102  ListCell *l;
103 
104  argtypes = (Oid *) palloc(nargs * sizeof(Oid));
105  i = 0;
106 
107  foreach(l, stmt->argtypes)
108  {
109  TypeName *tn = lfirst(l);
110  Oid toid = typenameTypeId(pstate, tn);
111 
112  argtypes[i++] = toid;
113  }
114  }
115 
116  /*
117  * Analyze the statement using these parameter types (any parameters
118  * passed in from above us will not be visible to it), allowing
119  * information about unknown parameters to be deduced from context.
120  */
121  query = parse_analyze_varparams(rawstmt, pstate->p_sourcetext,
122  &argtypes, &nargs);
123 
124  /*
125  * Check that all parameter types were determined.
126  */
127  for (i = 0; i < nargs; i++)
128  {
129  Oid argtype = argtypes[i];
130 
131  if (argtype == InvalidOid || argtype == UNKNOWNOID)
132  ereport(ERROR,
133  (errcode(ERRCODE_INDETERMINATE_DATATYPE),
134  errmsg("could not determine data type of parameter $%d",
135  i + 1)));
136  }
137 
138  /*
139  * grammar only allows PreparableStmt, so this check should be redundant
140  */
141  switch (query->commandType)
142  {
143  case CMD_SELECT:
144  case CMD_INSERT:
145  case CMD_UPDATE:
146  case CMD_DELETE:
147  /* OK */
148  break;
149  default:
150  ereport(ERROR,
151  (errcode(ERRCODE_INVALID_PSTATEMENT_DEFINITION),
152  errmsg("utility statements cannot be prepared")));
153  break;
154  }
155 
156  /* Rewrite the query. The result could be 0, 1, or many queries. */
157  query_list = QueryRewrite(query);
158 
159  /* Finish filling in the CachedPlanSource */
160  CompleteCachedPlan(plansource,
161  query_list,
162  NULL,
163  argtypes,
164  nargs,
165  NULL,
166  NULL,
167  CURSOR_OPT_PARALLEL_OK, /* allow parallel mode */
168  true); /* fixed result */
169 
170  /*
171  * Save the results.
172  */
174  plansource,
175  true);
176 }
List * QueryRewrite(Query *parsetree)
CachedPlanSource * CreateCachedPlan(RawStmt *raw_parse_tree, const char *query_string, CommandTag commandTag)
Definition: plancache.c:164
Definition: nodes.h:529
int errcode(int sqlerrcode)
Definition: elog.c:610
Query * parse_analyze_varparams(RawStmt *parseTree, const char *sourceText, Oid **paramTypes, int *numParams)
Definition: analyze.c:134
unsigned int Oid
Definition: postgres_ext.h:31
#define ERROR
Definition: elog.h:43
Node * stmt
Definition: parsenodes.h:1508
const char * p_sourcetext
Definition: parse_node.h:179
int stmt_len
Definition: parsenodes.h:1510
int stmt_location
Definition: parsenodes.h:1509
void StorePreparedStatement(const char *stmt_name, CachedPlanSource *plansource, bool from_sql)
Definition: prepare.c:427
#define InvalidOid
Definition: postgres_ext.h:36
#define ereport(elevel,...)
Definition: elog.h:144
CmdType commandType
Definition: parsenodes.h:112
#define makeNode(_type_)
Definition: nodes.h:577
char * name
Definition: parsenodes.h:3424
#define lfirst(lc)
Definition: pg_list.h:190
CommandTag CreateCommandTag(Node *parsetree)
Definition: utility.c:2246
void CompleteCachedPlan(CachedPlanSource *plansource, List *querytree_list, MemoryContext querytree_context, Oid *param_types, int num_params, ParserSetupHook parserSetup, void *parserSetupArg, int cursor_options, bool fixed_result)
Definition: plancache.c:336
Node * query
Definition: parsenodes.h:3426
static int list_length(const List *l)
Definition: pg_list.h:169
List * argtypes
Definition: parsenodes.h:3425
#define CURSOR_OPT_PARALLEL_OK
Definition: parsenodes.h:2715
void * palloc(Size size)
Definition: mcxt.c:949
int errmsg(const char *fmt,...)
Definition: elog.c:824
int i
#define copyObject(obj)
Definition: nodes.h:645
Definition: pg_list.h:50
Oid typenameTypeId(ParseState *pstate, const TypeName *typeName)
Definition: parse_type.c:291

◆ StorePreparedStatement()

void StorePreparedStatement ( const char *  stmt_name,
CachedPlanSource plansource,
bool  from_sql 
)

Definition at line 427 of file prepare.c.

References ereport, errcode(), errmsg(), ERROR, PreparedStatement::from_sql, GetCurrentStatementStartTimestamp(), HASH_ENTER, hash_search(), InitQueryHashTable(), PreparedStatement::plansource, PreparedStatement::prepare_time, and SaveCachedPlan().

Referenced by exec_parse_message(), and PrepareQuery().

430 {
431  PreparedStatement *entry;
433  bool found;
434 
435  /* Initialize the hash table, if necessary */
436  if (!prepared_queries)
438 
439  /* Add entry to hash table */
441  stmt_name,
442  HASH_ENTER,
443  &found);
444 
445  /* Shouldn't get a duplicate entry */
446  if (found)
447  ereport(ERROR,
448  (errcode(ERRCODE_DUPLICATE_PSTATEMENT),
449  errmsg("prepared statement \"%s\" already exists",
450  stmt_name)));
451 
452  /* Fill in the hash table entry */
453  entry->plansource = plansource;
454  entry->from_sql = from_sql;
455  entry->prepare_time = cur_ts;
456 
457  /* Now it's safe to move the CachedPlanSource to permanent memory */
458  SaveCachedPlan(plansource);
459 }
static void InitQueryHashTable(void)
Definition: prepare.c:405
CachedPlanSource * plansource
Definition: prepare.h:31
int64 TimestampTz
Definition: timestamp.h:39
int errcode(int sqlerrcode)
Definition: elog.c:610
void * hash_search(HTAB *hashp, const void *keyPtr, HASHACTION action, bool *foundPtr)
Definition: dynahash.c:908
static HTAB * prepared_queries
Definition: prepare.c:46
#define ERROR
Definition: elog.h:43
#define ereport(elevel,...)
Definition: elog.h:144
void SaveCachedPlan(CachedPlanSource *plansource)
Definition: plancache.c:452
TimestampTz prepare_time
Definition: prepare.h:33
int errmsg(const char *fmt,...)
Definition: elog.c:824
TimestampTz GetCurrentStatementStartTimestamp(void)
Definition: xact.c:792

Variable Documentation

◆ prepared_queries

HTAB* prepared_queries = NULL
static

Definition at line 46 of file prepare.c.