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List:       pgsql-performance
Subject:    Re: [PERFORM] which one is faster
From:       Grzegorz_Jaśkiewicz <gryzman () gmail ! com>
Date:       2010-10-26 12:20:33
Message-ID: AANLkTimx3bcBoxVeU1CLVONGn+UE-Cf14UzNPgciL6Vp () mail ! gmail ! com
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2010/10/26 Szymon Guz <mabewlun@gmail.com>:
>
> Well, strange. Why is that slower?

To answer that fully, you would need to see the implementation.
suffice to say,

count(a) does:

if (a <> NULL)
{
  count++;
}

and count(*) does:

  count++;



-- 
GJ

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