Fix leakage of cost_limit when multiple autovacuum workers are active. When using default autovacuum_vac_cost_limit, autovac_balance_cost relied on VacuumCostLimit to contain the correct global value ... but after the first time through in a particular worker process, it didn't, because we'd trashed it in previous iterations. Depending on the state of other autovac workers, this could result in a steady reduction of the effective cost_limit setting as a particular worker processed more and more tables, causing it to go slower and slower. Spotted by Simon Poole (bug #5759). Fix by saving and restoring the GUC variables in the loop in do_autovacuum.
In passing, improve a few comments. Back-patch to 8.3 ... the cost rebalancing code has been buggy since it was put in. Branch ------ REL8_4_STABLE Details ------- http://git.postgresql.org/gitweb?p=postgresql.git;a=commitdiff;h=fab2af30d6bb4ca893e2e9bf96863e6f1ce826d2 Modified Files -------------- src/backend/postmaster/autovacuum.c | 63 +++++++++++++++++++++++++---------- 1 files changed, 45 insertions(+), 18 deletions(-) -- Sent via pgsql-committers mailing list (pgsql-committers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-committers
