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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 (view raw or flat)
Thread:
Lists: pgsql-generalpgsql-hackers
>     (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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