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help / color / mirror / Atom feedFrom: Paul M. Aoki <aoki@CS.Berkeley.EDU>
To: postgres-arch@postgres.Berkeley.EDU
Subject: [bmcuyper@etro1.vub.ac.be: Postgres "main memory/optimisation"]
Date: Fri, 25 Nov 94 15:14:01 -0800
Message-ID: <199411252314.PAA14226@faerie.CS.Berkeley.EDU> (raw)
------- Forwarded Message
From: bmcuyper@etro1.vub.ac.be (Bernard De Cuyper)
To: aoki@CS.Berkeley.EDU
Subject: Postgres "main memory/optimisation"
Date: Fri, 25 Nov 1994 10:37:15 --100
Hi,
I have used the "main memory" option, however I would not
recommand its use to anyone. It works, but later on, I got stuck
when a problem occurs, the postgres system was no more able to retrieve
the "mirror classes" using the main memory options. Even if the quantity of
data is small !
> * retrieve (mSlice.all)\g
> Query sent to backend is "retrieve (mSlice.all)"
> WARN:Nov 25 09:37:00:cannot count blocks for mSlice
Another observation on speed, is that joins are quite slow on large relations even with hashing indexes. I do not know how the postgres is handelling joins internally, a thing which could be helpfull to rewrite queries in a more suitable way.
Sincerely,
Bernard
bmcuyper@etro.vub.ac.be
Dep. ETRO/IRIS
Free University of Brussels(VUB)
------- End of Forwarded Message
--
Paul M. Aoki | University of California at Berkeley
aoki@CS.Berkeley.EDU | Dept. of EECS, Computer Science Division (#1776)
| Berkeley, CA 94720-1776
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Subject: Re: [bmcuyper@etro1.vub.ac.be: Postgres "main memory/optimisation"]
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