Hi, 1. The following presentation uses serializable transaction isolation level to force a snapshot too old error. (http://momjian.us/main/writings/pgsql/features.pdf) Is it possible to get a snapshot too old error with active old_snapshot_threshold when the only used transaction isolation level is read committed? 2. Does activating old_snapshot_threshold have a negative impact on peformance? Regards, Marc-Olaf -- Sent via pgsql-admin mailing list (pgsql-admin@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin