match_special_index_operator don't work in 7.2.1

Your name : Andriy I Pilipenko
Your email address : bamby(at)marka(dot)net(dot)ua

System Configuration
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Architecture : Intel Pentium

Operating System : FreeBSD 4.5-STABLE

PostgreSQL version : PostgreSQL-7.2.1

Compiler used : gcc 2.95.3

Please enter a FULL description of your problem:
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I've upgraded from 7.0.3 to 7.2.1 and noticed that queries like

SELECT ... WHERE field LIKE 'something%'

take too much time to execute now.

Please describe a way to repeat the problem. Please try to provide a
concise reproducible example, if at all possible:
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bamby=# create table t (f varchar(100));
CREATE
bamby=# create index i_t__f on t(f);
CREATE
bamby=# SET enable_seqscan TO 'off';
SET VARIABLE
bamby=# EXPLAIN SELECT * from t where f = 'aa';
NOTICE: QUERY PLAN:

Index Scan using i_t__f on t (cost=0.00..17.07 rows=5 width=68)

EXPLAIN
bamby=# EXPLAIN SELECT * from t where f LIKE 'aa%';
NOTICE: QUERY PLAN:

Seq Scan on t (cost=100000000.00..100000022.50 rows=5 width=68)

EXPLAIN

If you know how this problem might be fixed, list the solution below:
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