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Implement EXPLAIN EXECUTE. By Neil Conway, with some kibitzing from

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Tom Lane.
This commit is contained in:
Tom Lane
2003-02-02 23:46:38 +00:00
parent 6adb475f77
commit c7bceca156
9 changed files with 275 additions and 142 deletions
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65
src/backend/commands/explain.c
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@ -1,20 +1,23 @@
/*
/*-------------------------------------------------------------------------
*
* explain.c
* Explain the query execution plan
* Explain query execution plans
*
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994-5, Regents of the University of California
*
* $Header: /cvsroot/pgsql/src/backend/commands/explain.c,v 1.99 2002/12/15 16:17:38 tgl Exp $
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/commands/explain.c,v 1.100 2003/02/02 23:46:38 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/genam.h"
#include "access/heapam.h"
#include "catalog/pg_type.h"
#include "commands/explain.h"
#include "commands/prepare.h"
#include "executor/executor.h"
#include "executor/instrument.h"
#include "lib/stringinfo.h"
@ -81,8 +84,11 @@ ExplainQuery(ExplainStmt *stmt, CommandDest dest)
if (query->commandType == CMD_UTILITY)
{
/* rewriter will not cope with utility statements */
do_text_output_oneline(tstate, "Utility statements have no plan structure");
/* Rewriter will not cope with utility statements */
if (query->utilityStmt && IsA(query->utilityStmt, ExecuteStmt))
ExplainExecuteQuery(stmt, tstate);
else
do_text_output_oneline(tstate, "Utility statements have no plan structure");
}
else
{
@ -119,10 +125,6 @@ ExplainOneQuery(Query *query, ExplainStmt *stmt, TupOutputState *tstate)
{
Plan *plan;
QueryDesc *queryDesc;
ExplainState *es;
StringInfo str;
double totaltime = 0;
struct timeval starttime;
/* planner will not cope with utility statements */
if (query->commandType == CMD_UTILITY)
@ -134,6 +136,13 @@ ExplainOneQuery(Query *query, ExplainStmt *stmt, TupOutputState *tstate)
return;
}
/*
* We don't support DECLARE CURSOR in EXPLAIN, but parser will take it
* because it's an OptimizableStmt
*/
if (query->isPortal)
elog(ERROR, "EXPLAIN / DECLARE CURSOR is not supported");
/* plan the query */
plan = planner(query);
@ -141,15 +150,34 @@ ExplainOneQuery(Query *query, ExplainStmt *stmt, TupOutputState *tstate)
if (plan == NULL)
return;
/* We don't support DECLARE CURSOR here */
Assert(!query->isPortal);
gettimeofday(&starttime, NULL);
/* Create a QueryDesc requesting no output */
queryDesc = CreateQueryDesc(query, plan, None, NULL, NULL,
stmt->analyze);
ExplainOnePlan(queryDesc, stmt, tstate);
}
/*
* ExplainOnePlan -
* given a planned query, execute it if needed, and then print
* EXPLAIN output
*
* This is exported because it's called back from prepare.c in the
* EXPLAIN EXECUTE case
*
* Note: the passed-in QueryDesc is freed when we're done with it
*/
void
ExplainOnePlan(QueryDesc *queryDesc, ExplainStmt *stmt,
TupOutputState *tstate)
{
struct timeval starttime;
double totaltime = 0;
ExplainState *es;
StringInfo str;
gettimeofday(&starttime, NULL);
/* call ExecutorStart to prepare the plan for execution */
ExecutorStart(queryDesc);
@ -160,7 +188,6 @@ ExplainOneQuery(Query *query, ExplainStmt *stmt, TupOutputState *tstate)
ExecutorRun(queryDesc, ForwardScanDirection, 0L);
/* We can't clean up 'till we're done printing the stats... */
totaltime += elapsed_time(&starttime);
}
@ -169,14 +196,14 @@ ExplainOneQuery(Query *query, ExplainStmt *stmt, TupOutputState *tstate)
es->printCost = true; /* default */
es->printNodes = stmt->verbose;
es->printAnalyze = stmt->analyze;
es->rtable = query->rtable;
es->rtable = queryDesc->parsetree->rtable;
if (es->printNodes)
{
char *s;
char *f;
s = nodeToString(plan);
s = nodeToString(queryDesc->plantree);
if (s)
{
if (Explain_pretty_print)
@ -195,7 +222,7 @@ ExplainOneQuery(Query *query, ExplainStmt *stmt, TupOutputState *tstate)
if (es->printCost)
{
explain_outNode(str, plan, queryDesc->planstate,
explain_outNode(str, queryDesc->plantree, queryDesc->planstate,
NULL, 0, es);
}