Re: [PROPOSAL] VACUUM Progress Checker.

>The total number of heap pages is known, and the total number of index
>pages is also known, so it's possible to derive a percentage out of
>this part.

The total number of index pages scanned during entire vacuum will depend on
number
of index scans that happens.
In order to extrapolate percent complete for phase two(index scan) we need
number of index scans * total index pages.
The number of index scans can vary from 1 to n (n depending on
maintenance_work_mem)

Summarizing suggestions in previous mails, following information can be
reported
Phase 1.heap pages scanned / total heap pages
Phase 2.index pages scanned / total index pages (across all indexes)
Phase 3.count of heap pages vacuumed

Additional info like number of index scans so far, number of dead tuples
being vacuumed in one batch can also be provided.

A combined estimate for vacuum percent complete can be provided by summing
up heap pages scanned, index pages scanned against total heap pages, total
index pages * number of index scans.

Thank you,
Rahila Syed