Re: [PERFORM] Bypassing useless ORDER BY in a VIEW

2008-02-28 Thread Dean Gibson (DB Administrator)
On 2008-02-28 09:13, Tom Lane wrote: A rule of thumb is that ORDER BY in a view is bad design, IMHO. regards, tom lane I was surprised to find out that apparently it's also a PostgreSQL extension; standard SQL apparently disallows ORDER BY in VIEWs: http://en.wik

Re: [PERFORM] Q on views and performance

2008-02-23 Thread Dean Gibson (DB Administrator)
On 2008-02-23 08:49, Dean Gibson (DB Administrator) wrote: Why 10,000 views??? What's wrong with the ONE view above? You DON'T want to be defining VIEWs based on actual tables VALUES; leave that to the SELECT. For that matter, what's wrong with the final SELECT I listed (b

Re: [PERFORM] Q on views and performance

2008-02-23 Thread Dean Gibson (DB Administrator)
On 2008-02-23 08:21, Kynn Jones wrote: ... 3. Why not write: CREATE VIEW txt AS SELECT a1.word AS word1, a1.type AS type1, a2.word AS word2, a2.type AS type2 FROM T a1 [LEFT] JOIN T a2 USING( zipk ); -- Use "LEFT" if appropriate SELECT word1, word1 FROM

Re: [PERFORM] Q on views and performance

2008-02-23 Thread Dean Gibson (DB Administrator)
On 2008-02-23 07:08, Dean Gibson (DB Administrator) wrote: ... SELECT word1, word1 FROM S JOIN txt ON word = word1 WHERE type1 = AND type2 = ; ... Oops that should be: SELECT word1, word2 FROM S JOIN txt ON word = word1 WHERE type1 = AND type2 = ; -- Mail to my list address MUST

Re: [PERFORM] Q on views and performance

2008-02-23 Thread Dean Gibson (DB Administrator)
On 2008-02-23 05:59, Kynn Jones wrote: On Fri, Feb 22, 2008 at 8:48 PM, Dean Gibson (DB Administrator) <[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>> wrote: ... Since you have experience working with views, let me ask you this. The converse strategy to the one I describe

Re: [PERFORM] Q on views and performance

2008-02-22 Thread Dean Gibson (DB Administrator)
On 2008-02-22 12:49, Kynn Jones wrote: Of course, I expect that using views V and V... would result in a loss in performance relative to a version that used bona fide tables T and T. My question is, how can I minimize this performance loss? That used to be my thoughts too, but I have found o

Re: [PERFORM] Optimizing No matching record Queries

2008-02-12 Thread Dean Gibson (DB Administrator)
On 2008-02-12 13:35, Pallav Kalva wrote: Hi, ... Table Definitions \d listing.listingstatus Table "listing.listingstatus" Column |Type | Modifiers -+-