On Thu, Dec 1, 2016 at 1:33 AM, xu jian <jame...@outlook.com> wrote:
> Please execute me if I am using the wrong mailing list, but I ask the
> question in pgsql-admin, looks like no one know the answer.
> we upgraded our pg db to 9.6, as we know, pg9.6 doesn't need full table scan
> in vacuum freeze.
> so we think if we have run vacuum freeze on the table, and there is no
> change on table which has been vacuum freeze before it should finish super
> However, it doesn't look like we expect. the next run of vacuum freeze still
> take long time. Then we run vacuum freeze with verbose. we notice it spends
> long time on scanning index.
> it seems even all rows are frozen on the data page, vacuum freeze still
> needs to scan all the index pages. if we drop the index, then vacuum freeze
> finishes immediately.
> Does anyone know if it is true?
Yeah that's true. The vacuum on each index is required in order to
update index statistics even if no updating on table.
> Btw, our table is large, and has about 40GB index files. is there anyway to
> make the vacuum freeze faster in this case?
I guess that there is no way.
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