From: | Andres Freund <andres(at)2ndquadrant(dot)com> |
---|---|
To: | pgsql-hackers(at)postgresql(dot)org |
Cc: | "Kevin Grittner" <kgrittn(at)mail(dot)com>, "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us>, "Simon Riggs" <simon(at)2ndquadrant(dot)com> |
Subject: | Re: Bugs in CREATE/DROP INDEX CONCURRENTLY |
Date: | 2012-10-18 09:20:23 |
Message-ID: | 201210181120.26268.andres@2ndquadrant.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
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?
Greetings,
Andres
--
Andres Freund http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services
Attachment | Content-Type | Size |
---|---|---|
0001-Fix-concurrency-issues-in-concurrent-index-drops.patch | text/x-patch | 7.6 KB |
0002-Fix-that-DROP-INDEX-CONCURRENT-could-leave-behind-an.patch | text/x-patch | 3.9 KB |
From | Date | Subject | |
---|---|---|---|
Next Message | Joel Jacobson | 2012-10-18 10:36:28 | Re: [PATCH] pg_dump: Sort overloaded functions in deterministic order |
Previous Message | Kyotaro HORIGUCHI | 2012-10-18 08:42:08 | [BUG] False indication in pg_stat_replication.sync_state |