Re: Using UPPER and TRIM (INDEX usage)

>
> How do I use "TRIM" and "UPPER" both in the SQL statement and still
use the index.
>
> I created an index on myTable in the following way
>
> CREATE INDEX index_fname_myTable ON myTable USING btree (upper(fname));
>
> Now the SQL I used was
>
>
> SELECT * FROM myTable where upper(trim(fname))= 'JOHN':: character
varying
>
> The postgresql doesnt use the index on fname in the above case.
>
> But if I use only "UPPER" in the SQL statement, the postgresql uses
the index.
> For eg. SELECT * FROM myTable where upper(fname)= 'JOHN':: character
varying

And what happens if you re-write it as

SELECT * FROM myTable where trim(upper(fname))= 'JOHN':: character varying

Alternatively try
CREATE FUNCTION uppertrim (character varying) returns character varying as '
select upper(trim($1));
' LANGUAGE SQL IMMUTABLE ;
and then
CREATE INDEX index_fname2_myTable ON myTable USING btree (uppertrim(fname));

Regards, Christoph