Re: Help! This group by stmt takes AGES

frankzaum_at_yahoo.de (Frank Zaum) wrote in message news:<4c1e5bbe.0204260540.5a186793_at_posting.google.com>...
> "Stephan Bressler" <stephan.bressler_at_pdb.sbs.de> wrote in message news:<aab0o4$t1a$1_at_news.mch.sbs.de>...
> > Hi Frank,
> >
> > did you analyzed space_values? I saw cases where the RBO selected a
> > nested-loop with 2 full-table-scans. This is usually _very_ expensive. Even
> > more if the inner table is a dictionary view.
> > CBO (used if tables are analyzed) probably will choose a hash join for this
> > query.
> >
> > Another solution might be to create a temporary copy of dba_tables, index it
> > properly and use this table for your space evaluation.
> >
> > Regards
> > Stephan
>
> hi again,
>
> yes i actually analyzed it (with all indexes, too) right before execution.
>
>
> regards, frank zaum

when i remove the group by , the query
is pretty fast and returns the right result for the sum per tablespace. using count gives the right values.

perhaps the statement can be changed to something not using the group by clause. but how?. in the end, i just want to select the values per day and tablespace, not the day itself (column datum contains trunc(sysdate)) but i dont know how to figure the correct select statement for that.

regards frank zaum Received on Fri Apr 26 2002 - 17:14:27 CDT