Hello,

I have three questions relating CONTAINING predicate.

In "The Firebird Book" I read on page 318 that indexes are used
also on search conditions against CONTAING predicates. I did some test
and, inspecting its PLAN, I found that it uses NATURAL order instead of
using an index.

1) ¿ Under which circumstances an index is used when the search has a
CONTAINING condition ?

Given the following two SQL clauses

SELECT * FROM TABLE1 WHERE UPPER(FIELD1) LIKE '%TEST%'
SELECT * FROM TABLE1 WHERE FIELD1 CONTAINING 'TEST'

2) Are they logically equivalent ?
3) Which of them is faster ?

Thanks in advance.
Aldo Caruso