> 1.Are they have composite indexes?
> If so, how did you update their statistics?
> update index statistics or update statistics?
> For ASE 15.7 you have to use 'update index statistics' command.
I've tried update statistics and update index statistics but as the search col doesn't have any index on it then I wouldn't expect this to help.
> 2.Below set options will help you to understand it.
> 2.1.check missing statistics
> set option show_missing_stats on
The code is
select * from A, B
where A.col1 > 1234 and A.col2 = "A"
and A.PK = B.PK
there are no indexes on A.col1 and A.col2 so I wouldn't expect stats on these columns which is shown by
NO STATS on column DB..A.col1
NO STATS on column DB..A.col1
Since almost any column in a table could be involved in a query would it make sense to create statistics on every column ? I can't think this would be realistic to do with the data volumes - but maybe I'm wrong ?
> 2.2.enable below options too
> set statistics io, plancost on
What should I be looking at ?
I'm not expecting ASE to have stats and get this query right in all cases.
I'm trying to understand the output from the set option show* so at least I can explain why ASE has chosen the plan it has. The output is huge and it not easy to read. I'm looking for something which might explain the output and what the most useful parts to look at.
