Re: 7.30 Performance problems
>We upgraded to 7.30 this past weekend and have noticed performance problems
with some queries.
Our organization has also recently attepted an upgade to 7.3 UC2 (HP_UX
10.20 OS), The performance seems good but we have one underlying problem to
solve. For some reason we have to append ownership to one of our tables if
the tablename has to be used in a column reference, for example in the
select statement, or join "case.int_case_num" has to be"informix.case.int_case_num" referencing the column without table
qualification is ok, and the reference to the "case" table in the from
clause does not require ownership to be specified. In addistion this only
occurs on our "case" table. No other table is affected. I have opened a case
on this but neither Informix or myself has come up with an explanation for
this oddity.
>I seem to be having a problem with my update statistics script (I think) so
that may be part of
>the problem. I dropped all distributions after the upgrade and let our
nightly process run the
>update statistics to recreate the distributions. The script says itfinishes successfully and
>in fact takes the same amount of time it did before to complete. However,
when I look in
>sysdistrib (that's the right place, right?), there is no data! If I update
for a specific table
>by hand using ISQL, the data appears in sysdistrib. I've since run the
update on all tables (by
>hand, my nightly process still seems to have problems which I can't figure
out since it worked
>before!) but I'm still having performance problems on queries.
We have written a small script that unloads the table name from systables,
and then performs update statistics in a loop for each table. The output is
redirected to a file where I can look to see if update statistics actually
ran for any table in question. I also do this for procedures. After the
script completes it does a grep for "Error/error" and the results if any are
mailed to me.
If any errors are noted I then try to run statistics for those
tables/procedures manually.