On 17 Jul 2015 07:14:02 -0700, [email protected] [firebird-support] <[email protected]> wrote: > CREATE UNIQUE INDEX UNQ_DETAILS_DATA ON DETAILS_DATA (ID_MASTER,ID_PARAM); > > when performing this query: > > WHERE > DD.ID_PARAM = 60 >
ID_PARAM is second field in the index. So the index cannot be used, because it would need to check all ID_MASTER values anyway. -- Virgo Pärna [email protected]
