diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/perform.sgml | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/doc/src/sgml/perform.sgml b/doc/src/sgml/perform.sgml index 2316df99a5c..ff93eaf8315 100644 --- a/doc/src/sgml/perform.sgml +++ b/doc/src/sgml/perform.sgml @@ -1,5 +1,5 @@ <!-- -$PostgreSQL: pgsql/doc/src/sgml/perform.sgml,v 1.50 2005/02/03 07:12:37 neilc Exp $ +$PostgreSQL: pgsql/doc/src/sgml/perform.sgml,v 1.51 2005/03/25 21:57:57 tgl Exp $ --> <chapter id="performance-tips"> @@ -320,16 +320,19 @@ EXPLAIN ANALYZE SELECT * FROM tenk1 t1, tenk2 t2 WHERE t1.unique1 < 50 AND t1 </para> <para> - The <literal>Total runtime</literal> shown by <command>EXPLAIN ANALYZE</command> includes - executor start-up and shut-down time, as well as time spent processing - the result rows. It does not include parsing, rewriting, or planning - time. For a <command>SELECT</> query, the total run time will normally be just a - little larger than the total time reported for the top-level plan node. - For <command>INSERT</>, <command>UPDATE</>, and <command>DELETE</> commands, the total run time may be - considerably larger, because it includes the time spent processing the - result rows. In these commands, the time for the top plan node - essentially is the time spent computing the new rows and/or locating - the old ones, but it doesn't include the time spent making the changes. + The <literal>Total runtime</literal> shown by <command>EXPLAIN + ANALYZE</command> includes executor start-up and shut-down time, as well + as time spent processing the result rows. It does not include parsing, + rewriting, or planning time. For a <command>SELECT</> query, the total + run time will normally be just a little larger than the total time + reported for the top-level plan node. For <command>INSERT</>, + <command>UPDATE</>, and <command>DELETE</> commands, the total run time + may be considerably larger, because it includes the time spent processing + the result rows. In these commands, the time for the top plan node + essentially is the time spent computing the new rows and/or locating the + old ones, but it doesn't include the time spent making the changes. + Time spent firing triggers, if any, is also outside the top plan node, + and is shown separately for each trigger. </para> <para> |