Hi Jeff,

1) If I have an index built for a given field FOO, and perform a query 
with "like" such as "FOO LIKE 'ABC...' " does it benefit from the 
index?  Or is it only queries with equality conditions that benefit from 
the index (eg: "FOO EQ 'ABC' ")?

An index can be used for a LIKE comparison with a literal element at the start 
but not if the ... is at the start.


2) If I have an index built with Empties=NO and then query with that 
indexed field ="", how does it handle the query? Does it not use the 
index at all?

Because the condition would be met by a null field and you have disabled 
indexing of null items, the index will not be used.

Beware of queries like
   WITH FLD < 4
when using NO.NULLS as again the condition is met by a null item, preventing 
use of an index, whereas
   WITH FLD > 4
could use an index.


Martin Phillips
Ladybridge Systems Ltd
17b Coldstream Lane, Hardingstone, Northampton NN4 6DB, England
+44 (0)1604-709200



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