Figures like 0.000 and 0.001 are normally brilliant, 0.333 is bad and
0.5 is even worse. How many records are there in the tables with the
lousy selectivity? Unless they are foreign keys, I'd recommend you to
drop these indexes (and sometimes even if it is a foreign key, e.g.
when the parent table never changes, you may be better off using
triggers).

Set

> > select rdb$index_name, rdb$statistics from rdb$indices
> >
> > to update the statistics use this command:
> > set statistics index <index_name>
> >
> > then commit and run again
> > to see the difference.
>
> PK_ITEM shows 0.000 before and after i run that. most of them show
> 0.000, there's 2 0.001's, 2 0.333's and 1 0.500 out of 25 indexes.
> what kind of figures should i be seeing?
>
> mark