On 18 October 2012 10:20, Andres Freund <and...@2ndquadrant.com> wrote: > On Thursday, October 18, 2012 06:12:02 AM Kevin Grittner wrote: >> Kevin Grittner wrote: >> > Hmm. The comment is probably better now, but I've been re-checking >> > the code, and I think my actual code change is completely wrong. >> > Give me a bit to sort this out. >> >> I'm having trouble seeing a way to make this work without rearranging >> the code for concurrent drop to get to a state where it has set >> indisvalid = false, made that visible to all processes, and ensured >> that all scans of the index are complete -- while indisready is still >> true. That is the point where TransferPredicateLocksToHeapRelation() >> could be safely called. Then we would need to set indisready = false, >> make that visible to all processes, and ensure that all access to the >> index is complete. I can't see where it works to set both flags at >> the same time. I want to sleep on it to see if I can come up with any >> other way, but right now that's the only way I'm seeing to make DROP >> INDEX CONCURRENTLY compatible with SERIALIZABLE transactions. :-( > > In a nearby bug I had to restructure the code that in a way thats similar to > this anyway, so that seems fine. Maybe you can fix the bug ontop of the two > attached patches?
First patch and first test committed. Working on second patch/test. -- Simon Riggs 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
