Re: help with query speed - Mailing list pgsql-general

From Jason Tesser
Subject Re: help with query speed
Date
Msg-id 04875CB4331F0240A0AD66F970978651011377EE@paul
Whole thread Raw
In response to help with query speed  ("Jason Tesser" <JTesser@nbbc.edu>)
List pgsql-general
Hi

> Hi
>
> > > I have the below query written.  I have removed a lot from the
> select
> > > Statement for simplicity sake.  The query takes way too long.
> > > I am moving from an Access backend to a Postgres back with
> > > Access in the front. The below query is taking like 14-20 seconds.
> > > Is their a better way I can write the joins.  I would think that
> > > Postgres should be fast than Access.  BTW I am writing these as
> > > Pass through queries so it is not a problem with Access.  I
> > > have Even ran the query directly against Postgres.
> > >
> > > SELECT
> > >   tblroster.transcriptlink
> > > FROM
> > >   tblroster
> > >   FULL OUTER JOIN testclass ON (tblroster.classlink =
> > > testclass.classid)
> > >   FULL OUTER JOIN tblqualitypoint ON (tblroster.lettergrade =
> > > tblqualitypoint.letter)
> > > ORDER BY
> > >   tblroster.transcriptlink
> >
> > Is there an index on:
> > tblroster.classlink
> >
> > Is there an index on:
> > testclass.classid
> >
> > Is there an index on:
> > tblroster.lettergrade
> >
> > Is there an index on:
> > tblqualitypoint.letter
> >
> > Is there an index on:
> > tblroster.transcriptlink
>
> I created the indexes and it speed up a little.  Still a little slower
> than
> Access though.  Which I think should not be.  The testclass is a view
> not
> A query so I cannot make an index there.

You didn't answer my question about whether they are the same types.
Are
they?

Yes they are.  I am going to try to get the analyze and vacuum thing
run.
I got an error when I tried to do it.  I am the owner of the tables and
Database but I think I need to be owner of some system tables or
Something.  Not sure.


---------------------------(end of broadcast)---------------------------
TIP 9: the planner will ignore your desire to choose an index scan if
your
      joining column's datatypes do not match

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