Re: Best database structure for timely ordered values

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От Bruce Momjian
Тема Re: Best database structure for timely ordered values
Дата
Msg-id 200012181646.LAA29528@candle.pha.pa.us
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Ответ на Re: Best database structure for timely ordered values  (Reiner Dassing <dassing@wettzell.ifag.de>)
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> > I assume the user is concerned about non-balanced btrees.  
> That is correct! 
> As I tested an example database with about 7 million entries on PostgreSQL V
> 6.5.2
> and the result of
> select count(*) from table;
> tooks about 3 minutes I have this concern.
> May be version 7.0.3 will give a better result.

The larger problem is that count(*) doesn't use the index at all.  It
just does a sequential scan of the heap table.

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
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