Here may be other problem.
Show us the result of EXPLAIN Analyze.
2011/8/8, Pavel Stehule <pavel.stehule@gmail.com>:
> Hello
>
> use a functional index
>
> http://www.postgresql.org/docs/8.4/interactive/indexes-expressional.html
>
> Regards
>
> Pavel Stehule
>
> 2011/8/8 - - <loh.law@hotmail.com>:
>> For a table where column col has an index, the query:
>> SELECT ... FROM ... WHERE col = MD5('')
>> doesn't seem to use an index but
>> SELECT ... FROM ... WHERE col = 'd41d8cd98f00b204e9800998ecf8427e'
>> does.
>>
>> Is this a gotcha?
>> I'm using PostgreSQL 8.4.8 on i686-pc-linux-gnu, compiled by GCC
>> gcc-4.5.real (Ubuntu/Linaro 4.5.2-8ubuntu4) 4.5.2, 32-bit
>>
>>
>>
>
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--
------------
pasman
