Vacuuming and already vacuumed table?

[Stephen Frost]

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

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[Christopher Browne]

In the last exciting episode, sf****@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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trap is sprung." <http://www.eviloverlord.com/>

[Matthew T. O'Connor]

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.
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