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| author | Simon Riggs <simon@2ndQuadrant.com> | 2011-02-16 19:29:37 +0000 |
|---|---|---|
| committer | Simon Riggs <simon@2ndQuadrant.com> | 2011-02-16 19:29:37 +0000 |
| commit | bca8b7f16a3e720794cb0afbdb3733be4f8d9c2c (patch) | |
| tree | 4d2e650f058ffa99af77f9068bf64a223de17246 /src/backend/utils/misc/guc.c | |
| parent | 65076269ea54a8cd6e39f066a208c7d13aceac0a (diff) | |
| download | postgresql-bca8b7f16a3e720794cb0afbdb3733be4f8d9c2c.tar.gz postgresql-bca8b7f16a3e720794cb0afbdb3733be4f8d9c2c.zip | |
Hot Standby feedback for avoidance of cleanup conflicts on standby.
Standby optionally sends back information about oldestXmin of queries
which is then checked and applied to the WALSender's proc->xmin.
GetOldestXmin() is modified slightly to agree with GetSnapshotData(),
so that all backends on primary include WALSender within their snapshots.
Note this does nothing to change the snapshot xmin on either master or
standby. Feedback piggybacks on the standby reply message.
vacuum_defer_cleanup_age is no longer used on standby, though parameter
still exists on primary, since some use cases still exist.
Simon Riggs, review comments from Fujii Masao, Heikki Linnakangas, Robert Haas
Diffstat (limited to 'src/backend/utils/misc/guc.c')
| -rw-r--r-- | src/backend/utils/misc/guc.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 56885576b92..55cbf757b49 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -1279,6 +1279,15 @@ static struct config_bool ConfigureNamesBool[] = }, { + {"hot_standby_feedback", PGC_SIGHUP, WAL_STANDBY_SERVERS, + gettext_noop("Allows feedback from a hot standby primary that will avoid query conflicts."), + NULL + }, + &hot_standby_feedback, + false, NULL, NULL + }, + + { {"allow_system_table_mods", PGC_POSTMASTER, DEVELOPER_OPTIONS, gettext_noop("Allows modifications of the structure of system tables."), NULL, |