Hello,
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.
http://rhaas.blogspot.com/2016/03/no-more-full-table-vacuums.html
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 faster.
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?
Btw, our table is large, and has about 40GB index files. is there anyway to
make the vacuum freeze faster in this case?
Thanks for the help.
James
