Query Approach and performance - Mailing list pgsql-general

From Morgan Curley
Subject Query Approach and performance
Date
Msg-id 4.3.2.7.2.20010817031239.028d90d0@e4media.com
Whole thread Raw
Responses Re: Query Approach and performance  (Martijn van Oosterhout <kleptog@svana.org>)
List pgsql-general
Hey everyone,
On average, are multiple simple queries better performance-wise than joins?
i.e.
select A.col1 from table1 A
select B.col2 from table2 B where B.col1 = A.col1
etc

vs

select A.col1, B.col2 from table1 A, table2 B where B.col1 = A.col1

Are joins better for small/large numbers of tables?
Is there a diff?
My approach to date has been to keep queries as simple as possible, and
when I see a need for complicated joins, I create a view and then do simple
queries against that.

Does pg cache queries like Oracle does so that repeated queries don't need
to go through the compile phase and run faster? Is this configurable?

Thanks,
Morgan


pgsql-general by date:

Previous
From: "Tille, Andreas"
Date:
Subject: Configuration of ODBC-driver
Next
From: Martijn van Oosterhout
Date:
Subject: Re: Query Approach and performance