Re: bad performances using hashjoin - Mailing list pgsql-performance

From Klint Gore
Subject Re: bad performances using hashjoin
Date
Msg-id 421939AD2A4.CE73KG@129.180.47.120
Whole thread Raw
In response to Re: bad performances using hashjoin  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: bad performances using hashjoin
List pgsql-performance
On Sun, 20 Feb 2005 13:46:10 -0500, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> sat_request rows.  If this is the case you actually need to optimize,
> probably the thing to do is to get rid of the ORDER BY clauses you
> evidently have in your views, so that there's some chance of building
> a fast-start plan.

Is having an order by in a view legal?  In sybase ASA, mssql it throws a
syntax error if there's an order by.

If so, does it do 2 sorts when you sort by something else?

i.e. if view is
   create view v1 as select * from table order by 1;
and the statment
   select * from v1 order by 2;
is run does it sort by 1 then resort by 2?

klint.

+---------------------------------------+-----------------+
: Klint Gore                            : "Non rhyming    :
: EMail   : kg@kgb.une.edu.au           :  slang - the    :
: Snail   : A.B.R.I.                    :  possibilities  :
: Mail      University of New England   :  are useless"   :
:           Armidale NSW 2351 Australia :     L.J.J.      :
: Fax     : +61 2 6772 5376             :                 :
+---------------------------------------+-----------------+

pgsql-performance by date:

Previous
From: Gaetano Mendola
Date:
Subject: Re: Effects of IDLE processes
Next
From: amrit@health2.moph.go.th
Date:
Subject: Re: Problem with 7.4.5 and webmin 1.8 in grant function