Re: Diferences between IN and EXISTS?

Thomas Kellerer wrote:

> zeljko, 04.02.2013 10:35:
>> Edson Richter wrote:
>>
>>> Hi!
>>>
>>> Assumptions: PostgreSQL 9.2.2, Win64, already run vacumm full freeze
>>> analyze. No problems in the database. I know there are 1247 records to
>>> be found.
>>> Why does these queries return different results:
>>>
>>>
>>> select count(*) from parcela
>>> where id not in (select parcela_id from cadastroservicoparcela);
>>
>> I'm always using
>> WHERE NOT id in (blabla) and never had such problems.
>>
>
> If blabla returns NULL values, then you will have problems eventually.

but it doesn't, then blabla should say WHERE NOT some ISNULL.

zeljko