index scan with functional indexes

I'm curious what the result of a reverse index does on a table with url
like data, so I did the following

create function fn_strrev(text) returns text as 'return reverse($_[0])'
language 'plperl' with (iscachable);

create index r_url_idx on url( fn_strrev(url));

vacuum analyze;

explain select * from url where url like fn_strrev('%beta12.html');
QUERY PLAN
---------------------------------------------------------
Seq Scan on url (cost=0.00..13281.70 rows=1 width=454)
Filter: ((url)::text ~~ 'lmth.21ateb%'::text)

Is it possible to get the planner to use an index scan ?

How?

the db is using locale 'C'

--
Dave Cramer
519 939 0336
ICQ # 1467551