Re: 8.3.1 query plan - Mailing list pgsql-general

From Martijn van Oosterhout
Subject Re: 8.3.1 query plan
Date
Msg-id 20080827163202.GB2514@svana.org
Whole thread Raw
In response to 8.3.1 query plan  (Steve Clark <sclark@netwolves.com>)
Responses Re: 8.3.1 query plan
List pgsql-general
On Wed, Aug 27, 2008 at 11:00:54AM -0400, Steve Clark wrote:
> So I did an explain and I see it is doing a seq scan in the last sub plan -
> there are about 375,000 rows
> in myevent - why isn't it using the index instead of doing a seq scan?
>
> create unique index indx1myevents on myevents (event_log_no)
> CREATE INDEX

Are there NULLs in this subtable? NOT IN must check the entire table
for NULLs. Try changing the query to use NOT EXISTS.

Have a nice day,
--
Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
> Please line up in a tree and maintain the heap invariant while
> boarding. Thank you for flying nlogn airlines.

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