Обсуждение: Vacuuming and already vacuumed table?

Greetings,

  Would it make sense for vacuum to keep a list of 'last vacuumed' or
  similar so that it doesn't vacuum a table which hasn't changed since
  the last time it was vacuum'd?  Seems to me that would be a pretty
  simple optimization which would help out alot on systems which have
  both a large set of tables which are relatively static and data which
  changes a great deal.  This is especially true for vacuum full which
  also locks the table.

  Thoughts?

      Thanks,

        Stephen

On Thu, 2003-08-28 at 16:53, Stephen Frost wrote:
>   Would it make sense for vacuum to keep a list of 'last vacuumed' or
>   similar so that it doesn't vacuum a table which hasn't changed since
>   the last time it was vacuum'd?  Seems to me that would be a pretty
>   simple optimization which would help out alot on systems which have
>   both a large set of tables which are relatively static and data which
>   changes a great deal.  This is especially true for vacuum full which
>   also locks the table.

7.4Beta has a contrib module called pg_autovacuum.  It attempts to do
exactly what you are talking about.  It only vacuums a table that has
had sufficient activity since the last vacuum.  It runs as a standalone
daemon.  Also, it can be used against 7.3 if that is what you are
running.

In the last exciting episode, sfrost@snowman.net (Stephen Frost) wrote:
>   Would it make sense for vacuum to keep a list of 'last vacuumed' or
>   similar so that it doesn't vacuum a table which hasn't changed since
>   the last time it was vacuum'd?  Seems to me that would be a pretty
>   simple optimization which would help out alot on systems which have
>   both a large set of tables which are relatively static and data which
>   changes a great deal.  This is especially true for vacuum full which
>   also locks the table.

See, in 7.4, the "pg_autovacuum" daemon.

It does much what you suggest...
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