I don't think that's the issue. It uses the index when it's a simple
inner join rather than an outer join. Nothing causes nulls to be
considered equal, so the joining condition would never be satisfied by
them, so the absence of nulls from the index should not play a role,
whether it's an inner or outer join.
"Niall Litchfield" <n-litchfield_at_audit-commission.gov.uk> wrote in message news:<3c7a18e4$0$230$ed9e5944_at_reading.news.pipex.net>...
> Maybe I'm reading this too quickly, but are you not getting this behaviour
> because your fk can contain nulls and these rows will not be indexed. In my
> exeprience oracle ius reasonably likely to ignore indexes even if hinted if
> the column is defined as nullable.
>
>
> --
> Niall Litchfield
> Oracle DBA
> Audit Commission UK
Received on Mon Feb 25 2002 - 12:18:34 CST
