Re: Performance - moving from oracle to postgresql - Mailing list pgsql-performance

From Merlin Moncure
Subject Re: Performance - moving from oracle to postgresql
Date
Msg-id 6EE64EF3AB31D5448D0007DD34EEB3415C2BC2@Herge.rcsinc.local
Whole thread Raw
In response to Performance - moving from oracle to postgresql  ("Greg Maples" <gregm@nimblefish.com>)
List pgsql-performance
> There are some immediate questions from our engineers about
performance
>
> "- Oracle has one particular performance enhancement that Postgres is
> missing.  If you do a select that returns 100,000 rows in a given
order,
> and all you want are rows 99101 to 99200, then Oracle can do that very
> efficiently.  With Postgres, it has to read the first 99200 rows and
> then discard the first 99100.  But...  If we really want to look at
> performance, then we ought to put together a set of benchmarks of some
> typical tasks."

I agree with Rod: you are correct but this is a very odd objection.  You
are declaring a set but are only interested in a tiny subset of that
based on arbitrary critera.  You can do this with cursors or with clever
querying (not without materializing the full set however), but why?

Merlin


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