Re: Feedback on getting rid of VACUUM FULL

On Wed, 2009-09-16 at 21:00 -0400, Tom Lane wrote:

> But if
> we get rid of old-style VACUUM FULL then we do need something to cover
> those few-and-far-between situations where you really do desperately
> need to compact a table in place; and a utility like this seems like a
> reasonable solution.  I'm thinking in particular that it should be
> possible to have it move just a bounded number of tuples at a time,
> so that you could do a VACUUM to clean out the indexes in between
> move passes.  Otherwise you run the risk of running out of disk space
> anyway, due to index bloat.

Agreed to all of the above, though I see some challenges.

The way I read the thread so far is that there are multiple
requirements:
* Shrink a table efficiently - when time and space available to do so
* Shrink a table in place - when no space available
* Shrink a table concurrently - when no dedicated time available

We probably can't do all of them at once, but we do need all of them, at
various times.

-- Simon Riggs           www.2ndQuadrant.com