[GENERAL] Why is PostgreSQL 9.1 not using index for simple equality select

2013-04-12 Thread Yang Zhang
Any hints with this question I had posted to SO? http://stackoverflow.com/questions/15965785/why-is-postgresql-9-1-not-using-index-for-simple-equality-select Pasted here as well. Thanks. My table `lead` has an index: \d lead ... Indexes: lead_pkey PRIMARY KEY, btree (id)

Re: [GENERAL] Why is PostgreSQL 9.1 not using index for simple equality select

2013-04-12 Thread John R Pierce
On 4/12/2013 1:03 AM, Yang Zhang wrote: db= explain select * from lead where email = 'blah'; QUERY PLAN Seq Scan on lead (cost=0.00..319599.38 rows=1 width=5108) Filter: (email =

Re: [GENERAL] Why is PostgreSQL 9.1 not using index for simple equality select

2013-04-12 Thread Yang Zhang
Doesn't seem to be the case. This table has been around for a while and should have been auto-analyzed by now. But anyway: db= analyze lead; ANALYZE db= explain select * from lead where email = 'f...@blah.com'; QUERY PLAN

Re: [GENERAL] Why is PostgreSQL 9.1 not using index for simple equality select

2013-04-12 Thread Alban Hertroys
On 12 April 2013 10:45, Yang Zhang yanghates...@gmail.com wrote: explain select * from lead where email = 'f...@blah.com'; What about: explain analyze select * from lead where email = 'f...@blah.com'; -- If you can't see the forest for the trees, Cut the trees and you'll see there is no

Re: [GENERAL] Why is PostgreSQL 9.1 not using index for simple equality select

2013-04-12 Thread John R Pierce
On 4/12/2013 1:45 AM, Yang Zhang wrote: db= explain select * from lead where email = 'f...@blah.com'; can you try explain analyze select * from lead where email = 'f...@blah.com'; ? -- john r pierce 37N 122W somewhere on the middle of the left coast

Re: [GENERAL] Why is PostgreSQL 9.1 not using index for simple equality select

2013-04-12 Thread Tom Lane
Yang Zhang yanghates...@gmail.com writes: db= explain select * from lead where email = 'blah'; QUERY PLAN Seq Scan on lead (cost=0.00..319599.38 rows=1 width=5108) Filter: (email =

Re: [GENERAL] Why is PostgreSQL 9.1 not using index for simple equality select

2013-04-12 Thread Yang Zhang
It's actually just `text`. I updated my SO question with some more info including explain analyze (no difference), \d, and your last incantation. Thanks! On Fri, Apr 12, 2013 at 7:11 AM, Tom Lane t...@sss.pgh.pa.us wrote: Yang Zhang yanghates...@gmail.com writes: db= explain select * from

Re: [GENERAL] Why is PostgreSQL 9.1 not using index for simple equality select

2013-04-12 Thread Tom Lane
Yang Zhang yanghates...@gmail.com writes: I updated my SO question with some more info including explain analyze (no difference), \d, and your last incantation. The question is being asked here, not in SO, and I find it rather impolite of you to expect me to go chasing off to some other forum

Re: [GENERAL] Why is PostgreSQL 9.1 not using index for simple equality select

2013-04-12 Thread Yang Zhang
Apologies for that Tom. I will paste the information in line once I'm back at my computer. I do appreciate your help. On Fri, Apr 12, 2013 at 10:24 AM, Tom Lane t...@sss.pgh.pa.us wrote: Yang Zhang yanghates...@gmail.com writes: I updated my SO question with some more info including explain