From: | Gregory Stark <stark(at)enterprisedb(dot)com> |
---|---|
To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
Cc: | Decibel! <decibel(at)decibel(dot)org>, Postgres Hackers <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: Regression in IN( field, field, field ) performance |
Date: | 2008-10-21 22:54:20 |
Message-ID: | 87wsg1sgo3.fsf@oxford.xeocode.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:
> Works fine for me, eg
...
> -> Bitmap Heap Scan on tenk1 b (cost=0.79..4.82 rows=3 width=244)
> Recheck Cond: (b.unique2 = ANY (ARRAY[a.unique1, a.ten, a.hundred]))
> -> Bitmap Index Scan on tenk1_unique2 (cost=0.00..0.79 rows=3 width=0
> )
> Index Cond: (b.unique2 = ANY (ARRAY[a.unique1, a.ten, a.hundred])
But that's an index on the lhs of the =ANY which in his example was just a
constant.
> You'll need to provide a concrete test case if you think there's
> something broken here.
I think he's looking for something like:
5 IN (col1,col2,col3)
resulting in a bitmap or of three index scans of three different indexes on
col1, col2, and col3.
--
Gregory Stark
EnterpriseDB http://www.enterprisedb.com
Ask me about EnterpriseDB's RemoteDBA services!
From | Date | Subject | |
---|---|---|---|
Next Message | Gregory Stark | 2008-10-21 23:00:08 | Re: Bitmap Indexes: request for feedback |
Previous Message | Myron Scott | 2008-10-21 22:50:33 | Re: Multi CPU Queries - Feedback and/or suggestions wanted! |