Обсуждение: New to PostgreSQL Question (Query Optimizer)

Hello,
    I'm newly into PostgreSQL from a SYBASE world and I haven't had a lot of
time to get into the code, so bare with me please.
    Is there a query optimizer in PostgreSQL?  or if not are there plans for
one?  And are there plans for anything like clustered indexes?
    I'm curious because one of the jobs I almost took a few years ago was
working on the query optimizer itself.  And please forgive me current
ignorance of the architecture of your engine.

Thanks, Rick.
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>
> Hello,
>     I'm newly into PostgreSQL from a SYBASE world and I haven't had a lot of
> time to get into the code, so bare with me please.
>     Is there a query optimizer in PostgreSQL?  or if not are there plans for
> one?  And are there plans for anything like clustered indexes?
>     I'm curious because one of the jobs I almost took a few years ago was
> working on the query optimizer itself.  And please forgive me current
> ignorance of the architecture of your engine.

We have a first-class optimizer.  If you look in the current sources,
the optimizer directory has a README that describes some of it.  You
will need the 6.3/snapshot release from ftp.postgresql.org to see the
README, or go to www.postgresql.org, and go to support/documentation,
and choose the nice program flowchart.  You can cruise around in there,
and see the source and README's.

--
Bruce Momjian
maillist@candle.pha.pa.us