Can anyone explain this: duplicate dbs.

От: SpaceBallOne
Тема: Can anyone explain this: duplicate dbs.
Дата: ,
Msg-id: BAY14-DAV38E580C92EFF811F1266ACC0E0@phx.gbl
(см: обсуждение, исходный текст)
Ответы: Re: Can anyone explain this: duplicate dbs.  (Christopher Kings-Lynne)
Re: Can anyone explain this: duplicate dbs.  (Christopher Kings-Lynne)
Re: Can anyone explain this: duplicate dbs.  (John A Meinel)
Список: pgsql-performance

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Can anyone explain this: duplicate dbs.  ("SpaceBallOne", )
 Re: Can anyone explain this: duplicate dbs.  (Christopher Kings-Lynne, )
 Re: Can anyone explain this: duplicate dbs.  (Christopher Kings-Lynne, )
  Re: Can anyone explain this: duplicate dbs.  (Tom Lane, )
 Re: Can anyone explain this: duplicate dbs.  (John A Meinel, )
  Re: Can anyone explain this: duplicate dbs.  (Tom Lane, )
  Re: Can anyone explain this: duplicate dbs.  (Bruno Wolff III, )
 Re: Can anyone explain this: duplicate dbs.  ("SpaceBallOne", )
  Re: Can anyone explain this: duplicate dbs.  (Christopher Kings-Lynne, )
  Re: Can anyone explain this: duplicate dbs.  (John A Meinel, )

Wondering if someone could explain a pecularity for me:

We have a database which takes 1000ms to perform a certain query on.

If I pg_dump that database then create a new database (e.g. "tempdb") and upload the dump file (thus making a duplicate) then the same query only takes 190ms !!
Vacuum, vacuum analyse, and vacuum full analyse does not seem to have an impact on these times.

Can anyone explain why this may be occurring and how I might be able to keep the original database running at the same speed as "tempdb"?

Thanks in advance,

Dave.

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