Обсуждение: Using LIKE expression problem..
Hi everybody..
Before anything else I would like to thank all those person who answers my previous question… again thank you very much
This is my question …
In my query .. Select * from table1 where lastname LIKE ‘PUNCIA%’..
In the query plan ..it uses seq scan rather than index scan .. why ? I have index on lastname, firtname…
Thanks
> In the query plan ..it uses seq scan rather than index scan .. why ? I > have index on lastname, firtname… Have you run VACUUM ANALYZE; on the table recently? Chris
Yes , I already do that but the same result .. LIKE uses seq scan -----Original Message----- From: pgsql-performance-owner@postgresql.org [mailto:pgsql-performance-owner@postgresql.org] On Behalf Of Christopher Kings-Lynne Sent: Wednesday, May 12, 2004 2:48 PM To: Michael Ryan S. Puncia Cc: pgsql-performance@postgresql.org Subject: Re: [PERFORM] Using LIKE expression problem.. > In the query plan ..it uses seq scan rather than index scan .. why ? I > have index on lastname, firtname. Have you run VACUUM ANALYZE; on the table recently? Chris ---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings
Are you in a non-C locale? Chris Michael Ryan S. Puncia wrote: > Yes , I already do that but the same result .. LIKE uses seq scan > > -----Original Message----- > From: pgsql-performance-owner@postgresql.org > [mailto:pgsql-performance-owner@postgresql.org] On Behalf Of Christopher > Kings-Lynne > Sent: Wednesday, May 12, 2004 2:48 PM > To: Michael Ryan S. Puncia > Cc: pgsql-performance@postgresql.org > Subject: Re: [PERFORM] Using LIKE expression problem.. > > >>In the query plan ..it uses seq scan rather than index scan .. why ? I >>have index on lastname, firtname. > > > Have you run VACUUM ANALYZE; on the table recently? > > Chris > > > ---------------------------(end of broadcast)--------------------------- > TIP 7: don't forget to increase your free space map settings >
Sorry .. I am a newbie and I don't know :(
How can I know that I am in C locale ?
How can I change my database to use C locale?
-----Original Message-----
From: pgsql-performance-owner@postgresql.org
[mailto:pgsql-performance-owner@postgresql.org] On Behalf Of Christopher
Kings-Lynne
Sent: Wednesday, May 12, 2004 3:59 PM
To: Michael Ryan S. Puncia
Cc: pgsql-performance@postgresql.org
Subject: Re: [PERFORM] Using LIKE expression problem..
Are you in a non-C locale?
Chris
Michael Ryan S. Puncia wrote:
> Yes , I already do that but the same result .. LIKE uses seq scan
>
> -----Original Message-----
> From: pgsql-performance-owner@postgresql.org
> [mailto:pgsql-performance-owner@postgresql.org] On Behalf Of Christopher
> Kings-Lynne
> Sent: Wednesday, May 12, 2004 2:48 PM
> To: Michael Ryan S. Puncia
> Cc: pgsql-performance@postgresql.org
> Subject: Re: [PERFORM] Using LIKE expression problem..
>
>
>>In the query plan ..it uses seq scan rather than index scan .. why ? I
>>have index on lastname, firtname.
>
>
> Have you run VACUUM ANALYZE; on the table recently?
>
> Chris
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 7: don't forget to increase your free space map settings
>
---------------------------(end of broadcast)---------------------------
TIP 5: Have you checked our extensive FAQ?
http://www.postgresql.org/docs/faqs/FAQ.html
Use the text_pattern_ops operator when creating the index, see: http://www.postgresql.org/docs/7.4/static/indexes-opclass.html Michael Ryan S. Puncia wrote: > Sorry .. I am a newbie and I don't know :( > How can I know that I am in C locale ? > How can I change my database to use C locale? > > > > -----Original Message----- > From: pgsql-performance-owner@postgresql.org > [mailto:pgsql-performance-owner@postgresql.org] On Behalf Of Christopher > Kings-Lynne > Sent: Wednesday, May 12, 2004 3:59 PM > To: Michael Ryan S. Puncia > Cc: pgsql-performance@postgresql.org > Subject: Re: [PERFORM] Using LIKE expression problem.. > > Are you in a non-C locale? > > Chris > > Michael Ryan S. Puncia wrote: > > >>Yes , I already do that but the same result .. LIKE uses seq scan >> >>-----Original Message----- >>From: pgsql-performance-owner@postgresql.org >>[mailto:pgsql-performance-owner@postgresql.org] On Behalf Of Christopher >>Kings-Lynne >>Sent: Wednesday, May 12, 2004 2:48 PM >>To: Michael Ryan S. Puncia >>Cc: pgsql-performance@postgresql.org >>Subject: Re: [PERFORM] Using LIKE expression problem.. >> >> >> >>>In the query plan ..it uses seq scan rather than index scan .. why ? I >>>have index on lastname, firtname. >> >> >>Have you run VACUUM ANALYZE; on the table recently? >> >>Chris >> >> >>---------------------------(end of broadcast)--------------------------- >>TIP 7: don't forget to increase your free space map settings >> > > > ---------------------------(end of broadcast)--------------------------- > TIP 5: Have you checked our extensive FAQ? > > http://www.postgresql.org/docs/faqs/FAQ.html > > > > ---------------------------(end of broadcast)--------------------------- > TIP 4: Don't 'kill -9' the postmaster >