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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2013-05-19 22:03:32 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2013-05-19 22:03:32 -0400 |
| commit | 2af0971f35a4a7b87312b83782d9bb0cc6a40ad0 (patch) | |
| tree | 2751f7dd7009680db9b3c923cce26d3379467e1b | |
| parent | d4337a0dcbd29e5b11c2157f808916de62de05e4 (diff) | |
| download | postgresql-2af0971f35a4a7b87312b83782d9bb0cc6a40ad0.tar.gz postgresql-2af0971f35a4a7b87312b83782d9bb0cc6a40ad0.zip | |
Clarify documentation of EXPLAIN (TIMING OFF) option.
Clarify that this option doesn't suppress measurement of the statement's
total runtime.
Greg Smith
| -rw-r--r-- | doc/src/sgml/ref/explain.sgml | 8 | ||||
| -rw-r--r-- | src/backend/commands/explain.c | 4 |
2 files changed, 9 insertions, 3 deletions
diff --git a/doc/src/sgml/ref/explain.sgml b/doc/src/sgml/ref/explain.sgml index 1f35a1d1552..74f33256b9e 100644 --- a/doc/src/sgml/ref/explain.sgml +++ b/doc/src/sgml/ref/explain.sgml @@ -182,11 +182,13 @@ ROLLBACK; <term><literal>TIMING</literal></term> <listitem> <para> - Include the actual startup time and time spent in the node in the output. + Include actual startup time and time spent in each node in the output. The overhead of repeatedly reading the system clock can slow down the query significantly on some systems, so it may be useful to set this - parameter to <literal>FALSE</literal> when only actual row counts, and not - exact times, are needed. + parameter to <literal>FALSE</literal> when only actual row counts, and + not exact times, are needed. Run time of the entire statement is + always measured, even when node-level timing is turned off with this + option. This parameter may only be used when <literal>ANALYZE</literal> is also enabled. It defaults to <literal>TRUE</literal>. </para> diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c index 38ce0efe031..c6398e3c8e7 100644 --- a/src/backend/commands/explain.c +++ b/src/backend/commands/explain.c @@ -414,6 +414,10 @@ ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, ExplainState *es, if (es->buffers) instrument_option |= INSTRUMENT_BUFFERS; + /* + * We always collect timing for the entire statement, even when + * node-level timing is off, so we don't look at es->timing here. + */ INSTR_TIME_SET_CURRENT(starttime); /* |