Re: using limit

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This really depends on the type of query you?re talking about. If there?s only one row in the table you?re querying then no, I don?t think it?ll change anything. If you?re querying a single row using a primary key it shouldn?t change anything. If you?re doing an aggregate query, say a sum of a bunch of rows, it also won?t improve performance.

 

If you?re doing a query on a table with multiple rows and not filtering by a primary key or other unique index then yes, it will improve the query.

 

From: pgsql-admin-owner@xxxxxxxxxxxxxx [mailto:pgsql-admin-owner@xxxxxxxxxxxxxx] On Behalf Of Anibal David Acosta
Sent: Thursday, December 16, 2010 11:19 AM
To: pgsql-admin@xxxxxxxxxxxxxx
Subject: using limit

 

Hi

I really like to do efficient SQL queries so, my question is if I am expecting no more than one row from a select, using  the LIMIT 1 could improve the performance?

 

If I use my logic, the LIMIT 1 instruction tell to postgres that stop searching when found 1 record, but maybe it is unnecessary

 

 

Thanks

 

Anibal


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