Re: How to append tables in a view - Mailing list pgsql-general

From Alban Hertroys
Subject Re: How to append tables in a view
Date
Msg-id 45D1905F.1020107@magproductions.nl
Whole thread Raw
In response to Re: How to append tables in a view  ("Shoaib Mir" <shoaibmir@gmail.com>)
List pgsql-general
Shoaib Mir wrote:
> So hmm a UNION with an ORDERY BY should be good for this scenario...

Only if the order matters to the OP, but he can always perform an ORDER
BY on the queries on his view. I don't really see the point.

The main difference between UNION and UINION ALL is that the latter
allows for duplicates, which removes the need to unduplicate the results
of the UNION (which requires ordering and is therefore relatively
expensive).

In short; if duplicates don't matter (or are desirtable even) UNION ALL
is faster.

--
Alban Hertroys
alban@magproductions.nl

magproductions b.v.

T: ++31(0)534346874
F: ++31(0)534346876
M:
I: www.magproductions.nl
A: Postbus 416
   7500 AK Enschede

// Integrate Your World //

pgsql-general by date:

Previous
From: "Shoaib Mir"
Date:
Subject: Re: How to append tables in a view
Next
From: "Pavan Deolasee"
Date:
Subject: Re: Dumb question - how to tell if autovacuum is doing its job in 8.2.x