Re: Hash Indexes
Amit Kapila <amit.kapila16@gmail.com>
From: Amit Kapila <amit.kapila16@gmail.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Jeff Janes <jeff.janes@gmail.com>,
Jesper Pedersen <jesper.pedersen@redhat.com>, Mithun Cy <mithun.cy@enterprisedb.com>,
pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2016-12-15T16:33:46Z
Lists: pgsql-hackers
Attachments
- fix_dirty_marking_v1.patch (application/octet-stream) patch v1
- fix_lock_chaining_v1.patch (application/octet-stream) patch v1
On Wed, Dec 14, 2016 at 10:47 PM, Robert Haas <robertmhaas@gmail.com> wrote: > On Wed, Dec 14, 2016 at 4:27 AM, Amit Kapila <amit.kapila16@gmail.com> wrote: >> >> Yeah, it will fix the problem in hashbucketcleanup, but there are two >> other problems that need to be fixed for which I can send a separate >> patch. By the way, as mentioned to you earlier that WAL patch already >> takes care of removing _hash_wrtbuf and simplified the logic wherever >> possible without introducing the logic of MarkBufferDirty multiple >> times under one lock. However, if you want to proceed with the >> current patch, then I can send you separate patches for the remaining >> problems as addressed in bug fix patch. > > That sounds good. > Attached are the two patches on top of remove-hash-wrtbuf. Patch fix_dirty_marking_v1.patch allows to mark the buffer dirty in one of the corner cases in _hash_freeovflpage() and avoids to mark dirty without need in _hash_squeezebucket(). I think this can be combined with remove-hash-wrtbuf patch. fix_lock_chaining_v1.patch fixes the chaining behavior (lock next overflow bucket page before releasing the previous bucket page) was broken in _hash_freeovflpage(). These patches can be applied in series, first remove-hash-wrtbuf, then fix_dirst_marking_v1.patch and then fix_lock_chaining_v1.patch. -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com
Commits
-
Remove _hash_wrtbuf() in favor of calling MarkBufferDirty().
- 25216c989384 10.0 landed
-
Fix race introduced by 6d46f4783efe457f74816a75173eb23ed8930020.
- 2f4193c3509a 10.0 cited
-
Improve hash index bucket split behavior.
- 6d46f4783efe 10.0 landed
-
Reduce pinning and buffer content locking for btree scans.
- 2ed5b87f96d4 9.5.0 cited