Re: Lock problem with autovacuum truncating heap

On Sat, Mar 26, 2011 at 2:30 PM, Jan Wieck <JanWieck(at)yahoo(dot)com> wrote:

> My current idea for a fix is to modify lazy_truncate_heap(). It does acquire
> and release the exclusive lock, so it should be possible to do this in
> smaller chunks, releasing and reacquiring the lock so that client
> transactions can get their work done as well.

Agreed, presumably with vacuum delay in there as well?

> At the same time I would
> change count_nondeletable_pages() so that it uses a forward scan direction
> (if that leads to a speedup).

Do we need that? Linux readahead works in both directions doesn't it?
Guess it wouldn't hurt too much.

BTW does it read the blocks at that point using a buffer strategy?

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 Simon Riggs                   http://www.2ndQuadrant.com/
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