Re: Best database structure for timely ordered values

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От Reiner Dassing
Тема Re: Best database structure for timely ordered values
Дата
Msg-id 3A3E3DF7.2D00A39D@wettzell.ifag.de
обсуждение исходный текст
Ответ на Re: Best database structure for timely ordered values  (Bruce Momjian <pgman@candle.pha.pa.us>)
Ответы Re: Best database structure for timely ordered values  (Bruce Momjian <pgman@candle.pha.pa.us>)
Список pgsql-sql
Bruce Momjian wrote:
> 
> > Reiner Dassing <dassing@wettzell.ifag.de> writes:
> > > The primary index must be the epoch.
> > > As there will be no deletion from this data I fear - due to the
> > > internal representation of B-trees - the performance will degrade very
> > > soon.
> >
> > Nonsense.  btree should work just fine for that.  Use a timestamp
> > column for the primary key, and away you go.
> >
> > (Actually, time alone doesn't seem like it'd be necessarily unique,
> > so maybe you don't want to call it a primary key.  But certainly
> > you can make a non-unique index on that column.)
> 
> 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.

> Ours are
> auto-balancing.
> 
> --
>   Bruce Momjian                        |  http://candle.pha.pa.us
>   pgman@candle.pha.pa.us               |  (610) 853-3000
>   +  If your life is a hard drive,     |  830 Blythe Avenue
>   +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

--
  Reiner Dassing


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