| From: | Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | pgsql-hackers(at)postgreSQL(dot)org |
| Subject: | Re: [HACKERS] Proposal for new SET variables for optimizer costs |
| Date: | 2000-02-05 22:01:59 |
| Message-ID: | 200002052201.RAA07126@candle.pha.pa.us |
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| Lists: | pgsql-hackers |
Looks great. I wouldn't change a thing in your proposal.
> I am about to implement some changes to the planner/optimizer's cost
> model, following up to the thread on pghackers beginning on 20 Jan.
> The main conclusion of that thread was that we needed to charge more for
> a page fetched nonsequentially than for a page fetched sequentially.
> After further investigation I have concluded that it is also appropriate
> to include explicit modeling of the cost of evaluation of WHERE clauses.
> For example, using the regression database and a query like
>
--
Bruce Momjian | http://www.op.net/~candle
pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 853-3000
+ If your life is a hard drive, | 830 Blythe Avenue
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