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/*-------------------------------------------------------------------------
*
* pquery.c
* POSTGRES process query command code
*
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/tcop/pquery.c,v 1.59 2003/03/10 03:53:51 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "executor/executor.h"
#include "tcop/pquery.h"
/*
* CreateQueryDesc
*/
QueryDesc *
CreateQueryDesc(Query *parsetree,
Plan *plantree,
CommandDest dest,
const char *portalName,
ParamListInfo params,
bool doInstrument)
{
QueryDesc *qd = (QueryDesc *) palloc(sizeof(QueryDesc));
qd->operation = parsetree->commandType; /* operation */
qd->parsetree = parsetree; /* parse tree */
qd->plantree = plantree; /* plan */
qd->dest = dest; /* output dest */
qd->portalName = portalName; /* name, if dest is a portal */
qd->params = params; /* parameter values passed into query */
qd->doInstrument = doInstrument; /* instrumentation wanted? */
/* null these fields until set by ExecutorStart */
qd->tupDesc = NULL;
qd->estate = NULL;
qd->planstate = NULL;
return qd;
}
/*
* FreeQueryDesc
*/
void
FreeQueryDesc(QueryDesc *qdesc)
{
/* Can't be a live query */
Assert(qdesc->estate == NULL);
/* Only the QueryDesc itself need be freed */
pfree(qdesc);
}
/*
* ProcessQuery
* Execute a query
*
* parsetree: the query tree
* plan: the plan tree for the query
* dest: where to send results
* completionTag: points to a buffer of size COMPLETION_TAG_BUFSIZE
* in which to store a command completion status string.
*
* completionTag may be NULL if caller doesn't want a status string.
*/
void
ProcessQuery(Query *parsetree,
Plan *plan,
CommandDest dest,
char *completionTag)
{
int operation = parsetree->commandType;
QueryDesc *queryDesc;
/*
* Check for special-case destinations
*/
if (operation == CMD_SELECT)
{
if (parsetree->into != NULL)
{
/*
* SELECT INTO table (a/k/a CREATE AS ... SELECT).
*
* Override the normal communication destination; execMain.c
* special-cases this case. (Perhaps would be cleaner to have
* an additional destination type?)
*/
dest = None;
}
}
/*
* Create the QueryDesc object
*/
queryDesc = CreateQueryDesc(parsetree, plan, dest, NULL, NULL, false);
/*
* Call ExecStart to prepare the plan for execution
*/
ExecutorStart(queryDesc);
/*
* And run the plan.
*/
ExecutorRun(queryDesc, ForwardScanDirection, 0L);
/*
* Build command completion status string, if caller wants one.
*/
if (completionTag)
{
Oid lastOid;
switch (operation)
{
case CMD_SELECT:
strcpy(completionTag, "SELECT");
break;
case CMD_INSERT:
if (queryDesc->estate->es_processed == 1)
lastOid = queryDesc->estate->es_lastoid;
else
lastOid = InvalidOid;
snprintf(completionTag, COMPLETION_TAG_BUFSIZE,
"INSERT %u %u", lastOid, queryDesc->estate->es_processed);
break;
case CMD_UPDATE:
snprintf(completionTag, COMPLETION_TAG_BUFSIZE,
"UPDATE %u", queryDesc->estate->es_processed);
break;
case CMD_DELETE:
snprintf(completionTag, COMPLETION_TAG_BUFSIZE,
"DELETE %u", queryDesc->estate->es_processed);
break;
default:
strcpy(completionTag, "???");
break;
}
}
/*
* Now, we close down all the scans and free allocated resources.
*/
ExecutorEnd(queryDesc);
FreeQueryDesc(queryDesc);
}
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