Mª José Sempere wrote:
> We are interested in installing the pgcrypto module of PostgreSQL for
> Windows, In order to use the function digest() for creating index on
> bytea type fields:
>
> create unique index my_index on my_table (digest(my_bytea_field,
> 'md5'));
Um, why would you want to use digest() just so that you can index a
bytea field?
regression=# select version();
version
-----------------------------------------------------------------------
PostgreSQL 7.4.5 on i686-pc-linux-gnu, compiled by GCC gcc (GCC) 3.3.3
20040412 (Red Hat Linux 3.3.3-7)
(1 row)
regression=# create table foo(f1 bytea, f2 text);
CREATE TABLE
regression=# create unique index idx1 on foo(f1);
CREATE INDEX
regression=# insert into foo values('abc\\001\\002xyz');
INSERT 32018907 1
regression=# set enable_seqscan to off;
SET
regression=# explain analyze select * from foo where f1 =
'abc\\001\\002xyz';
QUERY PLAN
------------------------------------------------------------------------
Index Scan using idx1 on foo (cost=0.00..4.82 rows=2 width=64)
(actual time=0.026..0.030 rows=1 loops=1)
Index Cond: (f1 = 'abc\\001\\002xyz'::bytea)
Total runtime: 0.114 ms
(3 rows)
HTH,
Joe
