I am using FB 2.5 in Windows.

I am trying to optimize some rather slow queries. Some (most?) indexes do not seem to be working.

For example - I have a query that I have simplified to

SELECT ID,ITEMNUMBER,ITEMDESC FROM MYTABLE ORDER BY ITEMNUMBER

I run this on a table of about 30,000 records. It takes ages, and IBExpert tells me that all the reads are UNINDEXED.

There is a primary index on ID, and an index on the sort field

ALTER TABLE LOCATIONITEMS ADD CONSTRAINT PK_LOCATIONITEMS PRIMARY KEY (ID);

CREATE INDEX LOCATIONITEMS_ITEMID ON LOCATIONITEMS (ITEMID);


This happens on many of my queries - I only show this one as it is very simple.

The plan is PLAN SORT (SORT ((LOCATIONITEMS NATURAL)))

Can anyone see why the index is not being used?