Re: [PERFORM] LISTEN / NOTIFY performance in 8.3

At 11:58 PM -0500 2/23/08, Tom Lane wrote: Joel Stevenson <[EMAIL PROTECTED]> writes: That's strange, I would not have thought that listen/notify behavior would change at all. How are you measuring this delay exactly? Can you put together a self-contained test case? Attached is a perl sc

Re: [PERFORM] LISTEN / NOTIFY performance in 8.3

Joel Stevenson <[EMAIL PROTECTED]> writes: > I have an existing app that provides a producer / consumer type of > queue and that uses the LISTEN / NOTIFY mechanism to signal the > consumers of new items arriving in the queue. The consumers then > process these items and issue a notify to signal

[PERFORM] LISTEN / NOTIFY performance in 8.3

Hi, I'm noticing a strange increase in the amount of time it takes to issue a NOTIFY statement. I have an existing app that provides a producer / consumer type of queue and that uses the LISTEN / NOTIFY mechanism to signal the consumers of new items arriving in the queue. The consumers then

Re: [PERFORM] Q on views and performance

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 (below)? SELECT a1

Re: [PERFORM] Q on views and performance

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

Hi, Dean. The system I'm working with is very similar "in spirit" to a large multilingual dictionary covering 100 languages. Using this analogy, the "type" column would correspond to the language, and the zipk column would correspond to some language-independent key associated with a concept ("co

Re: [PERFORM] Q on views and performance

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 be

Re: [PERFORM] Q on views and performance

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

Re: [PERFORM] Q on views and performance

Hi Kynn, Lets take these up as cases : Case A: keep one large table T and keep V1 V100 Case B: keep one large table T and store the the same data also in T1...T100 Case C: keep T1...T100 and store one V which is a UNION of T1 ... T100 1. The way I look at it, in case B although fetching dat

Re: [PERFORM] Q on views and performance

On Fri, Feb 22, 2008 at 8:48 PM, Dean Gibson (DB Administrator) < [EMAIL PROTECTED]> wrote: > 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 quest

Re: [PERFORM] Q on views and performance

On Fri, Feb 22, 2008 at 8:48 PM, Dean Gibson (DB Administrator) < [EMAIL PROTECTED]> wrote: > 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 quest

Re: [PERFORM] store A LOT of 3-tuples for comparisons

I am also wondering about the ordering and whether that matters. Can you have "he", "can", "drink" as well as "drink", "he", "can" and should they be considered the same? If so you will need a different tactic. ordering matters. So the 3-column tactic should work. Thanks for your advice!