Hi all Here's the final set of three patches on top of what's already committed.
The first is catalog_xmin logging, which is unchanged from the prior post. The 2nd is support for conflict with recovery, with changes that should address Andres's concerns there. The 3rd actually enables decoding on standby. Unlike the prior version, no attempt is made to check the walsender configuration for slot use, etc. The ugly code to try to mitigate races is also removed. Instead, if wal_level is logical the catalog_xmin sent by hot_standby_feedback is now the same as the xmin if there's no local slot holding it down. So we're always sending a catalog_xmin in feedback and we should always expect to have a valid local oldestCatalogXmin once hot_standby_feedback kicks in. This makes the race in slot creation no worse than the existing race between hot_standby_feedback establishment and the first queries run on a downstream, albeit with more annoying consequences. Apps can still ensure a slot created on standby is guaranteed safe and conflict-free by having a slot on the master first. I'm much happier with this. I'm still fixing some issues in the tests for 03 and tidying them up, but 03 should allow 01 and 02 to be reviewed in their proper context now. -- Craig Ringer http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
