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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2007-06-08 18:23:53 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2007-06-08 18:23:53 +0000 |
| commit | a04a423599b347325f9a73dfb2d533b24e1cbab3 (patch) | |
| tree | 5aeb620900a705222eb202c7b4b1d33266d1c190 /src/backend/utils/misc/guc.c | |
| parent | 6d6d14b6d52f7a709fba8fd23244a7de014f2048 (diff) | |
Arrange for large sequential scans to synchronize with each other, so that
when multiple backends are scanning the same relation concurrently, each page
is (ideally) read only once.
Jeff Davis, with review by Heikki and Tom.
Diffstat (limited to 'src/backend/utils/misc/guc.c')
| -rw-r--r-- | src/backend/utils/misc/guc.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 6e412e328a1..387c4ae1531 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -10,7 +10,7 @@ * Written by Peter Eisentraut <peter_e@gmx.net>. * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.395 2007/06/05 21:50:19 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.396 2007/06/08 18:23:52 tgl Exp $ * *-------------------------------------------------------------------- */ @@ -109,6 +109,9 @@ extern bool fullPageWrites; #ifdef TRACE_SORT extern bool trace_sort; #endif +#ifdef TRACE_SYNCSCAN +extern bool trace_syncscan; +#endif #ifdef DEBUG_BOUNDED_SORT extern bool optimize_bounded_sort; #endif @@ -970,6 +973,19 @@ static struct config_bool ConfigureNamesBool[] = }, #endif +#ifdef TRACE_SYNCSCAN + /* this is undocumented because not exposed in a standard build */ + { + {"trace_syncscan", PGC_USERSET, DEVELOPER_OPTIONS, + gettext_noop("Generate debugging output for synchronized scanning."), + NULL, + GUC_NOT_IN_SAMPLE + }, + &trace_syncscan, + false, NULL, NULL + }, +#endif + #ifdef DEBUG_BOUNDED_SORT /* this is undocumented because not exposed in a standard build */ { |