Re: [HACKERS] RE: [GENERAL] Long update query ? (also Re: [GENERAL] CNF vs. DNF)

From: Bruce Momjian <maillist(at)candle(dot)pha(dot)pa(dot)us>
To: daveh(at)insightdist(dot)com (David Hartwig)
Cc: taral(at)mail(dot)utexas(dot)edu, jwieck(at)debis(dot)com, hackers(at)postgreSQL(dot)org
Subject: Re: [HACKERS] RE: [GENERAL] Long update query ? (also Re: [GENERAL] CNF vs. DNF)
Date: 1998-10-06 02:23:13
Message-ID: 199810060223.WAA24245@candle.pha.pa.us
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> (A AND B) OR (C AND D) ==> (A AND B) UNION (C AND D)
>
> The rules to qualify are fairly strict. Must be have ANDs; rectangular in
> shape; all (VAR op CONST) type nodes; minimum of 10 nodes; etc. I was
> targeting the keysets queries generated by ODBC tools.
>
> As for the current direction this thread is going, (factoring) I have one
> word of caution. PREPARE. If you take this route, you will never be able
> to implement a workable PREPARE statement. I believe that in order for
> PostgrerSQL ever become a industrial strength client/server it must implement
> a PREPARE statement with parameters.

I see that adding nodes it going to mess up prepare, but we already add
extra nodes as part of part of "col in (1, 2, 3)."

I think the PARAM's we already use will be duplicated/removed and still
retain their values for substitution. They just may be in a different
order.

--
Bruce Momjian | http://www.op.net/~candle
maillist(at)candle(dot)pha(dot)pa(dot)us | (610) 853-3000
+ If your life is a hard drive, | 830 Blythe Avenue
+ Christ can be your backup. | Drexel Hill, Pennsylvania 19026

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