Re: [HACKERS] Index creation takes for ever - Mailing list pgsql-patches

From Bruce Momjian
Subject Re: [HACKERS] Index creation takes for ever
Date
Msg-id 200403170123.i2H1N9H10786@candle.pha.pa.us
Whole thread Raw
In response to Re: [HACKERS] Index creation takes for ever  (Manfred Koizar <mkoi-pg@aon.at>)
Responses Re: [HACKERS] Index creation takes for ever
List pgsql-patches
Where are we on this?   It seems like a win to me.

---------------------------------------------------------------------------

Manfred Koizar wrote:
> On Mon, 01 Dec 2003 13:32:10 -0500, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> >Manfred Koizar <mkoi-pg@aon.at> writes:
> >> comparetup_index() compares two IndexTuples.  The structure
> >> IndexTupleData consists basically of not much more than an ItemPointer,
> >> and the patch is not much more than adding a comparison of two
> >> ItemPointers.  So how does the patch introduce a new low level
> >> implementation dependency?
> >
> >Because it sorts on tuple position, which is certainly about as low
> >level as you can get.
>
> The patch affects only the sort during index creation.  Mapping key
> values to tuple positions is the sole purpose of an index.  The notion
> that an index should not care for tuple positions looks a bit strange to
> me.
>
> >  More to the point, though, no evidence has been
> >provided that this is a good idea.
>
> The test script I posted with the patch shows that the patch produces
> more efficient b-tree indices when there are lots of duplicates.
>
> Servus
>  Manfred
>
> ---------------------------(end of broadcast)---------------------------
> TIP 4: Don't 'kill -9' the postmaster
>

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