On 2014-06-26 22:47:47 -0600, Ryan Johnson wrote: > Hi, > > As part of a research project, I'm trying to change Read Committed isolation > to use HeapTupleSatisfiesNow rather than acquiring a new snapshot at every > command [1]. Things appear to have gone reasonably well so far, except > certain queries fail with "ERROR: non-MVCC snapshots are not supported in > index-only scans."
You're aware that unless you employ additional locking you can simply miss individual rows or see them several times because of concurrent updates? The reason it has worked (< 9.4) for system catalogs is that updates of rows were only performed while objects were locked access exclusively - that's the reason why some places in the code use inplace updates btw... Greetings, Andres Freund -- Andres Freund 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
