count(*)

Hi. What affects the execution speed of count(*):

SQL> select count(*) from table_a;

   COUNT(*)

     382784

Elapsed: 00:00:00.28
SQL> select count(*) from table_b;

   COUNT(*)

     382648

Elapsed: 00:00:05.40

The tables have a similar amount of rows, yet the count on table_b is noticably slower than the count on table_a.

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Morten Primdahl         Caput A/S          Phone +45 70 12 24 42
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