Re: quick question abt pg_dump and restore

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От Alvaro Herrera
Тема Re: quick question abt pg_dump and restore
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Msg-id 20080109152750.GD4651@alvh.no-ip.org
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Ответ на Re: quick question abt pg_dump and restore  ("Josh Harrison" <joshques@gmail.com>)
Ответы Re: quick question abt pg_dump and restore  ("Josh Harrison" <joshques@gmail.com>)
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Josh Harrison escribió:

> Another quick question...When you issue a query like this
> select * from dummy limit 10
> What 10 rows are fetched? like first 10  or last 10 or  the first 10 from
> first block or.... ?

Any 10.  (First 10 in the physical table _if_ a seqscan is used).

> And this query always returns the same 10 rows (when there are no
> updates/deletes)

Yes, assuming there is no VACUUM or CLUSTER either.  And no inserts
either if there is free space on the first pages.

You really shouldn't trust it.

--
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.

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