RE: Postgres not using index on views - Mailing list pgsql-performance

From Rick Vincent
Subject RE: Postgres not using index on views
Date
Msg-id DM6PR04MB4923EA84340249CF303E2089C1D40@DM6PR04MB4923.namprd04.prod.outlook.com
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In response to Postgres not using index on views  ("David G. Johnston" <david.g.johnston@gmail.com>)
List pgsql-performance

Dear all,

 

Changing the function signature to IMMUTABLE worked like a dream.  No issue now.  Sorry for my confusion on VOLATILE being created as the default.  Thanks to everyone for your help!

 

Kind regards,

Rick Vincent

 

From: David G. Johnston <david.g.johnston@gmail.com>
Sent: Friday, April 17, 2020 4:55 PM
To: Rick Vincent <rvincent@temenos.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>; Justin Pryzby <pryzby@telsasoft.com>; pgsql-performance@postgresql.org; Manoj Kumar <manojkumar@temenos.com>; Herve Aubert <haubert@temenos.com>
Subject: Postgres not using index on views

 

On Friday, April 17, 2020, Rick Vincent <rvincent@temenos.com> wrote:

Hi,

 

I was wondering if anyone can explain the below problem.  Should a bug be logged for this?

 

Kind regards,

Rick

 

_____________________________________________
From: Rick Vincent
Sent: Tuesday, April 7, 2020 11:08 AM
To: 'Tom Lane' <tgl@sss.pgh.pa.us>; Justin Pryzby <pryzby@telsasoft.com>
Cc: pgsql-performance@postgresql.org; Manoj Kumar <manojkumar@temenos.com>; Herve Aubert <haubert@temenos.com>
Subject: RE: Postgres not using index on views

 

 

Hi Tom,

 

The function is defined as below, so no use of VOLATILE.  Let me know if you need any other information.  I am hoping the below will further clarify the issue.

 

 

IIUC as Tom wrote you have volatile functions (implied/default as Thomas wrote) attached to view column outputs and the planner will not optimize those away.

 

Mark your function immutable (assuming it is) and retry your experiment with the where clause query. 

 

David J.


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