database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-05 07:21:24 +03:00
Code Activity

Add an EXPLAIN (BUFFERS) option to show buffer-usage statistics.

Browse Source 
This patch also removes buffer-usage statistics from the track_counts
output, since this (or the global server statistics) is deemed to be a better
interface to this information.

Itagaki Takahiro, reviewed by Euler Taveira de Oliveira.
This commit is contained in:
Robert Haas
2009-12-15 04:57:48 +00:00
parent 6f1bf75d50
commit cddca5ec13
25 changed files with 274 additions and 140 deletions
Download Patch File Download Diff File Expand all files Collapse all files

47
src/backend/executor/instrument.c
View File

@ -7,7 +7,7 @@
* Copyright (c) 2001-2009, PostgreSQL Global Development Group
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/executor/instrument.c,v 1.22 2009/01/01 17:23:41 momjian Exp $
* $PostgreSQL: pgsql/src/backend/executor/instrument.c,v 1.23 2009/12/15 04:57:47 rhaas Exp $
*
*-------------------------------------------------------------------------
*/
@ -17,14 +17,28 @@
#include "executor/instrument.h"
BufferUsage pgBufferUsage;
static void BufferUsageAccumDiff(BufferUsage *dst,
const BufferUsage *add, const BufferUsage *sub);
/* Allocate new instrumentation structure(s) */
Instrumentation *
InstrAlloc(int n)
InstrAlloc(int n, int instrument_options)
{
Instrumentation *instr = palloc0(n * sizeof(Instrumentation));
Instrumentation *instr;
/* we don't need to do any initialization except zero 'em */
/* timer is always required for now */
Assert(instrument_options & INSTRUMENT_TIMER);
instr = palloc0(n * sizeof(Instrumentation));
if (instrument_options & INSTRUMENT_BUFFERS)
{
int i;
for (i = 0; i < n; i++)
instr[i].needs_bufusage = true;
}
return instr;
}
@ -37,6 +51,10 @@ InstrStartNode(Instrumentation *instr)
INSTR_TIME_SET_CURRENT(instr->starttime);
else
elog(DEBUG2, "InstrStartNode called twice in a row");
/* initialize buffer usage per plan node */
if (instr->needs_bufusage)
instr->bufusage_start = pgBufferUsage;
}
/* Exit from a plan node */
@ -59,6 +77,11 @@ InstrStopNode(Instrumentation *instr, double nTuples)
INSTR_TIME_SET_ZERO(instr->starttime);
/* Adds delta of buffer usage to node's count. */
if (instr->needs_bufusage)
BufferUsageAccumDiff(&instr->bufusage,
&pgBufferUsage, &instr->bufusage_start);
/* Is this the first tuple of this cycle? */
if (!instr->running)
{
@ -95,3 +118,19 @@ InstrEndLoop(Instrumentation *instr)
instr->firsttuple = 0;
instr->tuplecount = 0;
}
static void
BufferUsageAccumDiff(BufferUsage *dst,
const BufferUsage *add,
const BufferUsage *sub)
{
/* dst += add - sub */
dst->shared_blks_hit += add->shared_blks_hit - sub->shared_blks_hit;
dst->shared_blks_read += add->shared_blks_read - sub->shared_blks_read;
dst->shared_blks_written += add->shared_blks_written - sub->shared_blks_written;
dst->local_blks_hit += add->local_blks_hit - sub->local_blks_hit;
dst->local_blks_read += add->local_blks_read - sub->local_blks_read;
dst->local_blks_written += add->local_blks_written - sub->local_blks_written;
dst->temp_blks_read += add->temp_blks_read - sub->temp_blks_read;
dst->temp_blks_written += add->temp_blks_written - sub->temp_blks_written;
}