Re: LIMIT OFFSET with DB view vs plain SQL

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi Raj,

I have long time without working on pgsql performance, but you can try materialized views or if you are already using its try apply some performance tips... 

This are some link i found in a fast search, but if you solution is going by this way this can be a kickstart to solve your problem.. 

https://thoughtbot.com/blog/advanced-postgres-performance-tips

http://www.postgresqltutorial.com/postgresql-materialized-views/

Take in account that materialized views have to be filled and use additional space.. 

Hope this can help you solving you issue



On Thu, Mar 28, 2019, 7:44 PM Raj Gandhi <raj01gandhi@xxxxxxxxx> wrote:
+ pgsql-performance 

On Thu, Mar 28, 2019 at 6:41 PM Raj Gandhi <raj01gandhi@xxxxxxxxx> wrote:

Hi everyone,

 

I’m using LIMIT offset with DB view. Looks like query planner is applying the LIMIT for DB view at the end after processing all rows.

When running same SQL that was used to create the DB view, LIMIT is applied earlier so the query is much faster.

 

Explain plan using DB view

https://explain.depesz.com/s/gzjQ

 

Explain plan using raw SQL

https://explain.depesz.com/s/KgwO

 

In both tests LIMIT was 100 with offset  = 0.

Is there any way to force DB view to apply limit earlier?

 

Thanks,

Raj


[Postgresql General]     [Postgresql PHP]     [PHP Users]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Yosemite]

  Powered by Linux