SQL tuning?

[Tiemo Hollmann TB]

Hi,

beeing not a SQL expert I wonder if the performance of my plain SELECT
statement can be designed faster.

What I am doing right now (and that is already pretty good performing) is
the following. To make my code easy to maintain I have only one single build
of the SQL string. I have to compare 4 indexed fields in a WHERE clause.
Each of the 4 fields can be included in the selection or not and every
combination of the 4 fields can be selected. So what I did is:

    put "SELECT " & tSelect & " FROM t1" &\

    " WHERE t1.f1 LIKE " & s1 " \

    and t1.f2 LIKE " & s2 " \

    and t1.f3 LIKE " & s3 " \

    and t1.f4 LIKE " & s4 into tSQL

and my search variables s1,s2,s3,s4 can contain a search value
("%searchstring%") or, if I want to exclude this field from the search I
just put a "%" into that search variable. Btw I need the comparison with
LIKE "%searchstring%" for each field. I wanted to avoid to build 16
different SQL stings, depending on which one of the search values has a
content or not.

Is there anything what I can design better while keeping my code as simple
and compact, as it is right now?

Thanks for any coaching

Tiemo