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Prevent auto_explain from changing the output of a user's EXPLAIN.

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Commit af7914c662, which introduced the
EXPLAIN (TIMING) option, for some reason coded explain.c to look at
planstate->instrument->need_timer rather than es->timing to decide
whether to print timing info.  However, the former flag might get set
as a result of contrib/auto_explain wanting timing information.  We
certainly don't want activation of auto_explain to change user-visible
statement behavior, so fix that.

Also fix an independent bug introduced in the same patch: in the code
path for a never-executed node with a machine-friendly output format,
if timing was selected, it would fail to print the Actual Rows and Actual
Loops items.

Per bug #10404 from Tomonari Katsumata.  Back-patch to 9.2 where the
faulty code was introduced.
This commit is contained in:
Tom Lane
2014-05-20 12:20:52 -04:00
parent e0c04b7c38
commit 0266a9c781
1 changed files with 16 additions and 11 deletions
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23
src/backend/commands/explain.c
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@@ -1145,11 +1145,18 @@ ExplainNode(PlanState *planstate, List *ancestors,
/* /*
* We have to forcibly clean up the instrumentation state because we * We have to forcibly clean up the instrumentation state because we
* haven't done ExecutorEnd yet. This is pretty grotty ... * haven't done ExecutorEnd yet. This is pretty grotty ...
*
* Note: contrib/auto_explain could cause instrumentation to be set up
* even though we didn't ask for it here. Be careful not to print any
* instrumentation results the user didn't ask for. But we do the
* InstrEndLoop call anyway, if possible, to reduce the number of cases
* auto_explain has to contend with.
*/ */
if (planstate->instrument) if (planstate->instrument)
InstrEndLoop(planstate->instrument); InstrEndLoop(planstate->instrument);
if (planstate->instrument && planstate->instrument->nloops > 0) if (es->analyze &&
planstate->instrument && planstate->instrument->nloops > 0)
{ {
double nloops = planstate->instrument->nloops; double nloops = planstate->instrument->nloops;
double startup_sec = 1000.0 * planstate->instrument->startup / nloops; double startup_sec = 1000.0 * planstate->instrument->startup / nloops;
@@ -1158,7 +1165,7 @@ ExplainNode(PlanState *planstate, List *ancestors,
if (es->format == EXPLAIN_FORMAT_TEXT) if (es->format == EXPLAIN_FORMAT_TEXT)
{ {
if (planstate->instrument->need_timer) if (es->timing)
appendStringInfo(es->str, appendStringInfo(es->str,
" (actual time=%.3f..%.3f rows=%.0f loops=%.0f)", " (actual time=%.3f..%.3f rows=%.0f loops=%.0f)",
startup_sec, total_sec, rows, nloops); startup_sec, total_sec, rows, nloops);
@@ -1169,7 +1176,7 @@ ExplainNode(PlanState *planstate, List *ancestors,
} }
else else
{ {
if (planstate->instrument->need_timer) if (es->timing)
{ {
ExplainPropertyFloat("Actual Startup Time", startup_sec, 3, es); ExplainPropertyFloat("Actual Startup Time", startup_sec, 3, es);
ExplainPropertyFloat("Actual Total Time", total_sec, 3, es); ExplainPropertyFloat("Actual Total Time", total_sec, 3, es);
@@ -1180,20 +1187,18 @@ ExplainNode(PlanState *planstate, List *ancestors,
} }
else if (es->analyze) else if (es->analyze)
{ {
if (es->format == EXPLAIN_FORMAT_TEXT) if (es->format == EXPLAIN_FORMAT_TEXT)
appendStringInfo(es->str, " (never executed)"); appendStringInfo(es->str, " (never executed)");
else if (planstate->instrument->need_timer) else
{
if (es->timing)
{ {
ExplainPropertyFloat("Actual Startup Time", 0.0, 3, es); ExplainPropertyFloat("Actual Startup Time", 0.0, 3, es);
ExplainPropertyFloat("Actual Total Time", 0.0, 3, es); ExplainPropertyFloat("Actual Total Time", 0.0, 3, es);
} }
else
{
ExplainPropertyFloat("Actual Rows", 0.0, 0, es); ExplainPropertyFloat("Actual Rows", 0.0, 0, es);
ExplainPropertyFloat("Actual Loops", 0.0, 0, es); ExplainPropertyFloat("Actual Loops", 0.0, 0, es);
} }
} }
/* in text format, first line ends here */ /* in text format, first line ends here */
@@ -1362,7 +1367,7 @@ ExplainNode(PlanState *planstate, List *ancestors,
} }
/* Show buffer usage */ /* Show buffer usage */
if (es->buffers) if (es->buffers && planstate->instrument)
{ {
const BufferUsage *usage = &planstate->instrument->bufusage; const BufferUsage *usage = &planstate->instrument->bufusage;