pgsql-server/src/backend/commands analyze.c

CVSROOT: /cvsroot
Module name: pgsql-server
Changes by: tgl(at)postgresql(dot)org 02/08/10 20:08:48

Modified files:
src/backend/commands: analyze.c

Log message:
Now that we allow ANALYZE to run inside a transaction block, the locks
it takes could be held for quite awhile after the analyze step completes.
Rethink locking of pg_statistic in light of this fact. The original
scheme took an exclusive lock on pg_statistic, which was okay when the
lock could be expected to be released shortly, but that doesn't hold
anymore. Back off to a normal writer's lock (RowExclusiveLock). This
allows concurrent ANALYZE of nonoverlapping sets of tables, at the price
that concurrent ANALYZEs of the same table may fail with 'tuple
concurrently updated'.