Re: Seq Scan used instead of Index Scan - Mailing list pgsql-performance

From Mark Kirkwood
Subject Re: Seq Scan used instead of Index Scan
Date
Msg-id 4ECD9E19.8080303@catalyst.net.nz
Whole thread Raw
In response to Seq Scan used instead of Index Scan  (Gary Warner <gar@cis.uab.edu>)
List pgsql-performance
Can you post your non-default postgresql.conf settings? (I'd hazard a
guess that you have effective_cache_size set to the default 128MB).

Best wishes

Mark

On 24/11/11 11:24, Gary Warner wrote:
> Very Fast Version:
>
> Recently my database stopped respecting one of my indexes, which took a query that should run in "subsecond response
time"and turning it into something that with small data sets runs in the 7-10 minute range and with large data sets
runsin the 30 minute - eternity range. 
>
> Explain Analyze tells me that what used to be an Index Scan has become a Seq Scan, doing a full table scan through
140million records. 
>
> Any thoughts on why that happens?
>


pgsql-performance by date:

Previous
From: Claudio Freire
Date:
Subject: Re: Seq Scan used instead of Index Scan
Next
From: Tom Lane
Date:
Subject: Re: Seq Scan used instead of Index Scan