mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-08-25 20:07:20 +02:00
I (Andres) was more than a bit hasty in committing33001fd7a7
after last minute changes, leading to a number of problems (jit output was only shown for JIT in parallel workers, and just EXPLAIN without ANALYZE didn't work). Lukas luckily found these issues quickly. Instead of combining instrumentation in in standard_ExecutorEnd(), do so on demand in the new ExplainPrintJITSummary(). Also update a documentation example of the JIT output, changed in52050ad8eb
. Author: Lukas Fittl, with minor changes by me Discussion: https://postgr.es/m/CAP53PkxmgJht69pabxBXJBM+0oc6kf3KHMborLP7H2ouJ0CCtQ@mail.gmail.com Backpatch: 11, where JIT compilation was introduced
373 lines
9.2 KiB
C
373 lines
9.2 KiB
C
/*-------------------------------------------------------------------------
|
|
*
|
|
* auto_explain.c
|
|
*
|
|
*
|
|
* Copyright (c) 2008-2018, PostgreSQL Global Development Group
|
|
*
|
|
* IDENTIFICATION
|
|
* contrib/auto_explain/auto_explain.c
|
|
*
|
|
*-------------------------------------------------------------------------
|
|
*/
|
|
#include "postgres.h"
|
|
|
|
#include <limits.h>
|
|
|
|
#include "commands/explain.h"
|
|
#include "executor/instrument.h"
|
|
#include "jit/jit.h"
|
|
#include "utils/guc.h"
|
|
|
|
PG_MODULE_MAGIC;
|
|
|
|
/* GUC variables */
|
|
static int auto_explain_log_min_duration = -1; /* msec or -1 */
|
|
static bool auto_explain_log_analyze = false;
|
|
static bool auto_explain_log_verbose = false;
|
|
static bool auto_explain_log_buffers = false;
|
|
static bool auto_explain_log_triggers = false;
|
|
static bool auto_explain_log_timing = true;
|
|
static int auto_explain_log_format = EXPLAIN_FORMAT_TEXT;
|
|
static bool auto_explain_log_nested_statements = false;
|
|
static double auto_explain_sample_rate = 1;
|
|
|
|
static const struct config_enum_entry format_options[] = {
|
|
{"text", EXPLAIN_FORMAT_TEXT, false},
|
|
{"xml", EXPLAIN_FORMAT_XML, false},
|
|
{"json", EXPLAIN_FORMAT_JSON, false},
|
|
{"yaml", EXPLAIN_FORMAT_YAML, false},
|
|
{NULL, 0, false}
|
|
};
|
|
|
|
/* Current nesting depth of ExecutorRun calls */
|
|
static int nesting_level = 0;
|
|
|
|
/* Saved hook values in case of unload */
|
|
static ExecutorStart_hook_type prev_ExecutorStart = NULL;
|
|
static ExecutorRun_hook_type prev_ExecutorRun = NULL;
|
|
static ExecutorFinish_hook_type prev_ExecutorFinish = NULL;
|
|
static ExecutorEnd_hook_type prev_ExecutorEnd = NULL;
|
|
|
|
/* Is the current query sampled, per backend */
|
|
static bool current_query_sampled = true;
|
|
|
|
#define auto_explain_enabled() \
|
|
(auto_explain_log_min_duration >= 0 && \
|
|
(nesting_level == 0 || auto_explain_log_nested_statements))
|
|
|
|
void _PG_init(void);
|
|
void _PG_fini(void);
|
|
|
|
static void explain_ExecutorStart(QueryDesc *queryDesc, int eflags);
|
|
static void explain_ExecutorRun(QueryDesc *queryDesc,
|
|
ScanDirection direction,
|
|
uint64 count, bool execute_once);
|
|
static void explain_ExecutorFinish(QueryDesc *queryDesc);
|
|
static void explain_ExecutorEnd(QueryDesc *queryDesc);
|
|
|
|
|
|
/*
|
|
* Module load callback
|
|
*/
|
|
void
|
|
_PG_init(void)
|
|
{
|
|
/* Define custom GUC variables. */
|
|
DefineCustomIntVariable("auto_explain.log_min_duration",
|
|
"Sets the minimum execution time above which plans will be logged.",
|
|
"Zero prints all plans. -1 turns this feature off.",
|
|
&auto_explain_log_min_duration,
|
|
-1,
|
|
-1, INT_MAX,
|
|
PGC_SUSET,
|
|
GUC_UNIT_MS,
|
|
NULL,
|
|
NULL,
|
|
NULL);
|
|
|
|
DefineCustomBoolVariable("auto_explain.log_analyze",
|
|
"Use EXPLAIN ANALYZE for plan logging.",
|
|
NULL,
|
|
&auto_explain_log_analyze,
|
|
false,
|
|
PGC_SUSET,
|
|
0,
|
|
NULL,
|
|
NULL,
|
|
NULL);
|
|
|
|
DefineCustomBoolVariable("auto_explain.log_verbose",
|
|
"Use EXPLAIN VERBOSE for plan logging.",
|
|
NULL,
|
|
&auto_explain_log_verbose,
|
|
false,
|
|
PGC_SUSET,
|
|
0,
|
|
NULL,
|
|
NULL,
|
|
NULL);
|
|
|
|
DefineCustomBoolVariable("auto_explain.log_buffers",
|
|
"Log buffers usage.",
|
|
NULL,
|
|
&auto_explain_log_buffers,
|
|
false,
|
|
PGC_SUSET,
|
|
0,
|
|
NULL,
|
|
NULL,
|
|
NULL);
|
|
|
|
DefineCustomBoolVariable("auto_explain.log_triggers",
|
|
"Include trigger statistics in plans.",
|
|
"This has no effect unless log_analyze is also set.",
|
|
&auto_explain_log_triggers,
|
|
false,
|
|
PGC_SUSET,
|
|
0,
|
|
NULL,
|
|
NULL,
|
|
NULL);
|
|
|
|
DefineCustomEnumVariable("auto_explain.log_format",
|
|
"EXPLAIN format to be used for plan logging.",
|
|
NULL,
|
|
&auto_explain_log_format,
|
|
EXPLAIN_FORMAT_TEXT,
|
|
format_options,
|
|
PGC_SUSET,
|
|
0,
|
|
NULL,
|
|
NULL,
|
|
NULL);
|
|
|
|
DefineCustomBoolVariable("auto_explain.log_nested_statements",
|
|
"Log nested statements.",
|
|
NULL,
|
|
&auto_explain_log_nested_statements,
|
|
false,
|
|
PGC_SUSET,
|
|
0,
|
|
NULL,
|
|
NULL,
|
|
NULL);
|
|
|
|
DefineCustomBoolVariable("auto_explain.log_timing",
|
|
"Collect timing data, not just row counts.",
|
|
NULL,
|
|
&auto_explain_log_timing,
|
|
true,
|
|
PGC_SUSET,
|
|
0,
|
|
NULL,
|
|
NULL,
|
|
NULL);
|
|
|
|
DefineCustomRealVariable("auto_explain.sample_rate",
|
|
"Fraction of queries to process.",
|
|
NULL,
|
|
&auto_explain_sample_rate,
|
|
1.0,
|
|
0.0,
|
|
1.0,
|
|
PGC_SUSET,
|
|
0,
|
|
NULL,
|
|
NULL,
|
|
NULL);
|
|
|
|
EmitWarningsOnPlaceholders("auto_explain");
|
|
|
|
/* Install hooks. */
|
|
prev_ExecutorStart = ExecutorStart_hook;
|
|
ExecutorStart_hook = explain_ExecutorStart;
|
|
prev_ExecutorRun = ExecutorRun_hook;
|
|
ExecutorRun_hook = explain_ExecutorRun;
|
|
prev_ExecutorFinish = ExecutorFinish_hook;
|
|
ExecutorFinish_hook = explain_ExecutorFinish;
|
|
prev_ExecutorEnd = ExecutorEnd_hook;
|
|
ExecutorEnd_hook = explain_ExecutorEnd;
|
|
}
|
|
|
|
/*
|
|
* Module unload callback
|
|
*/
|
|
void
|
|
_PG_fini(void)
|
|
{
|
|
/* Uninstall hooks. */
|
|
ExecutorStart_hook = prev_ExecutorStart;
|
|
ExecutorRun_hook = prev_ExecutorRun;
|
|
ExecutorFinish_hook = prev_ExecutorFinish;
|
|
ExecutorEnd_hook = prev_ExecutorEnd;
|
|
}
|
|
|
|
/*
|
|
* ExecutorStart hook: start up logging if needed
|
|
*/
|
|
static void
|
|
explain_ExecutorStart(QueryDesc *queryDesc, int eflags)
|
|
{
|
|
/*
|
|
* For rate sampling, randomly choose top-level statement. Either all
|
|
* nested statements will be explained or none will.
|
|
*/
|
|
if (auto_explain_log_min_duration >= 0 && nesting_level == 0)
|
|
current_query_sampled = (random() < auto_explain_sample_rate *
|
|
MAX_RANDOM_VALUE);
|
|
|
|
if (auto_explain_enabled() && current_query_sampled)
|
|
{
|
|
/* Enable per-node instrumentation iff log_analyze is required. */
|
|
if (auto_explain_log_analyze && (eflags & EXEC_FLAG_EXPLAIN_ONLY) == 0)
|
|
{
|
|
if (auto_explain_log_timing)
|
|
queryDesc->instrument_options |= INSTRUMENT_TIMER;
|
|
else
|
|
queryDesc->instrument_options |= INSTRUMENT_ROWS;
|
|
if (auto_explain_log_buffers)
|
|
queryDesc->instrument_options |= INSTRUMENT_BUFFERS;
|
|
}
|
|
}
|
|
|
|
if (prev_ExecutorStart)
|
|
prev_ExecutorStart(queryDesc, eflags);
|
|
else
|
|
standard_ExecutorStart(queryDesc, eflags);
|
|
|
|
if (auto_explain_enabled() && current_query_sampled)
|
|
{
|
|
/*
|
|
* Set up to track total elapsed time in ExecutorRun. Make sure the
|
|
* space is allocated in the per-query context so it will go away at
|
|
* ExecutorEnd.
|
|
*/
|
|
if (queryDesc->totaltime == NULL)
|
|
{
|
|
MemoryContext oldcxt;
|
|
|
|
oldcxt = MemoryContextSwitchTo(queryDesc->estate->es_query_cxt);
|
|
queryDesc->totaltime = InstrAlloc(1, INSTRUMENT_ALL);
|
|
MemoryContextSwitchTo(oldcxt);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* ExecutorRun hook: all we need do is track nesting depth
|
|
*/
|
|
static void
|
|
explain_ExecutorRun(QueryDesc *queryDesc, ScanDirection direction,
|
|
uint64 count, bool execute_once)
|
|
{
|
|
nesting_level++;
|
|
PG_TRY();
|
|
{
|
|
if (prev_ExecutorRun)
|
|
prev_ExecutorRun(queryDesc, direction, count, execute_once);
|
|
else
|
|
standard_ExecutorRun(queryDesc, direction, count, execute_once);
|
|
nesting_level--;
|
|
}
|
|
PG_CATCH();
|
|
{
|
|
nesting_level--;
|
|
PG_RE_THROW();
|
|
}
|
|
PG_END_TRY();
|
|
}
|
|
|
|
/*
|
|
* ExecutorFinish hook: all we need do is track nesting depth
|
|
*/
|
|
static void
|
|
explain_ExecutorFinish(QueryDesc *queryDesc)
|
|
{
|
|
nesting_level++;
|
|
PG_TRY();
|
|
{
|
|
if (prev_ExecutorFinish)
|
|
prev_ExecutorFinish(queryDesc);
|
|
else
|
|
standard_ExecutorFinish(queryDesc);
|
|
nesting_level--;
|
|
}
|
|
PG_CATCH();
|
|
{
|
|
nesting_level--;
|
|
PG_RE_THROW();
|
|
}
|
|
PG_END_TRY();
|
|
}
|
|
|
|
/*
|
|
* ExecutorEnd hook: log results if needed
|
|
*/
|
|
static void
|
|
explain_ExecutorEnd(QueryDesc *queryDesc)
|
|
{
|
|
if (queryDesc->totaltime && auto_explain_enabled() && current_query_sampled)
|
|
{
|
|
double msec;
|
|
|
|
/*
|
|
* Make sure stats accumulation is done. (Note: it's okay if several
|
|
* levels of hook all do this.)
|
|
*/
|
|
InstrEndLoop(queryDesc->totaltime);
|
|
|
|
/* Log plan if duration is exceeded. */
|
|
msec = queryDesc->totaltime->total * 1000.0;
|
|
if (msec >= auto_explain_log_min_duration)
|
|
{
|
|
ExplainState *es = NewExplainState();
|
|
|
|
es->analyze = (queryDesc->instrument_options && auto_explain_log_analyze);
|
|
es->verbose = auto_explain_log_verbose;
|
|
es->buffers = (es->analyze && auto_explain_log_buffers);
|
|
es->timing = (es->analyze && auto_explain_log_timing);
|
|
es->summary = es->analyze;
|
|
es->format = auto_explain_log_format;
|
|
|
|
ExplainBeginOutput(es);
|
|
ExplainQueryText(es, queryDesc);
|
|
ExplainPrintPlan(es, queryDesc);
|
|
if (es->analyze && auto_explain_log_triggers)
|
|
ExplainPrintTriggers(es, queryDesc);
|
|
if (es->costs)
|
|
ExplainPrintJITSummary(es, queryDesc);
|
|
ExplainEndOutput(es);
|
|
|
|
/* Remove last line break */
|
|
if (es->str->len > 0 && es->str->data[es->str->len - 1] == '\n')
|
|
es->str->data[--es->str->len] = '\0';
|
|
|
|
/* Fix JSON to output an object */
|
|
if (auto_explain_log_format == EXPLAIN_FORMAT_JSON)
|
|
{
|
|
es->str->data[0] = '{';
|
|
es->str->data[es->str->len - 1] = '}';
|
|
}
|
|
|
|
/*
|
|
* Note: we rely on the existing logging of context or
|
|
* debug_query_string to identify just which statement is being
|
|
* reported. This isn't ideal but trying to do it here would
|
|
* often result in duplication.
|
|
*/
|
|
ereport(LOG,
|
|
(errmsg("duration: %.3f ms plan:\n%s",
|
|
msec, es->str->data),
|
|
errhidestmt(true)));
|
|
|
|
pfree(es->str->data);
|
|
}
|
|
}
|
|
|
|
if (prev_ExecutorEnd)
|
|
prev_ExecutorEnd(queryDesc);
|
|
else
|
|
standard_ExecutorEnd(queryDesc);
|
|
}
|