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

Bruce Momjian <maillist@candle.pha.pa.us>

From: Bruce Momjian <maillist@candle.pha.pa.us>
To: taral@mail.utexas.edu (Taral)
Cc: hackers@postgreSQL.org
Date: 1998-10-02T17:40:39Z
Lists: pgsql-hackers, pgsql-general
[Charset iso-8859-1 unsupported, filtering to ASCII...]
> > > Create a temporary oid hash? (for each table selected on, I guess)
> >
> > What I did with indexes was to run the previous OR clause index
> > restrictions through the qualification code, and make sure it failed,
> > but I am not sure how that is going to work with a more complex WHERE
> > clause.  Perhaps I need to restrict this to just simple cases of
> > constants, which are easy to pick out an run through.  Doing this with
> > joins would be very hard, I think.
> 
> Actually, I was thinking more of an index of returned rows... After each
> subquery, the backend would check each row to see if it was already in the
> index... Simple duplicate check, in other words. Of course, I don't know how
> well this would behave with large tables being returned...
> 
> Anyone else have some ideas they want to throw in?

I certainly think we are heading in the direction for a good general
solution.


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