Re: Why do I have holes in my pages?

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От Sergey Konoplev
Тема Re: Why do I have holes in my pages?
Дата
Msg-id CAL_0b1vitYZ2a9m=zJaNj9K0yyABtoHC4F3HHo+Szqp5Y0davw@mail.gmail.com
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Ответ на Re: Why do I have holes in my pages?  (Jeff Janes <jeff.janes@gmail.com>)
Список pgsql-general
On Fri, Sep 21, 2012 at 11:30 AM, Jeff Janes <jeff.janes@gmail.com> wrote:
> At that point the ctid can be re-used, but only if someone actually
> wants a "new" ctid on that page.  An ordinary vacuum will not close up
> the gaps on un-used ctids.  Only a vaccum full will do that.

There are a couple of ways to do that except the vacuum full that
locks the table exclusively.

1. pg_reorg can re-organize tables on a postgres database without
locks. However it requires twice the space of the table size and might
lead to IO spikes.
2. pgcompactor a tables and indexes bloat reducing tool, without
locking also. It is slower than pg_reorg but does its job more gently.

>
> The space used by these ctid gaps is not large, and as the OP
> discovered, his wasted space was in fact happening outside of the
> database itself.
>
> Cheers,
>
> Jeff
>
>
> --
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--
Sergey Konoplev

a database and software architect
http://www.linkedin.com/in/grayhemp

Jabber: gray.ru@gmail.com Skype: gray-hemp Phone: +14158679984


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