Gavin Sherry wrote:
On Thu, 16 Jun 2005, [ISO-8859-1] Hans-J�rgen Sch�nig wrote:
2) By no fault of its own, autovacuum's level of granularity is the table
level. For people dealing with non-trivial amounts of data (and we're not
talking gigabytes or terabytes here), this is a serious drawback. Vacuum
at peak times can cause very intense IO bursts -- even with the
enhancements in 8.0. I don't think the solution to the problem is to give
users the impression that it is solved and then vacuum their tables during
peak periods. I cannot stress this enough.
I completly agree with Gavin - integrating this kind of thing into the
backend writer or integrate it with FSM would be the ideal solution.
I guess everybody who has already vacuumed a 2 TB relation will agree
here. VACUUM is not a problem for small "my cat Minka" databases.
However, it has been a real problem on large, heavy-load databases. I
have even seen people splitting large tables and join them with a view
to avoid long vacuums and long CREATE INDEX operations (i am not joking
- this is serious).
I think this gets away from my point a little. People with 2 TB tables can
take care of themselves, as can people who've taken the time to partition
their tables to speed up vacuum. I'm more concerned about the majority of
people who fall in the middle -- between the hobbiest and the high end
data centre.
Thanks,
Gavin
I think your approach will help all of them.
If we had some sort of autovacuum (which is packages with most distros
anyway - having it in the core is nice as well) and a mechanism to
improve realloaction / vacuum speed we have solved all problems.
i do think that 2 tb can take care of themselves. the question is,
however, whether the database can do what they want ...
thanks a lot,
hans
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