Re: Add index scan progress to pg_stat_progress_vacuum

On 21/12/2021 00:05, Peter Geoghegan wrote:
> * Some index AMs don't work like nbtree and GiST in that they cannot
> do their scan sequentially -- they have to do something like a
> logical/keyspace order scan instead, which is *totally* different to
> heapam (not just a bit different). There is no telling how many times
> each page will be accessed in these other index AMs, and in what
> order, even under optimal conditions. We should arguably not even try
> to provide any granular progress information here, since it'll
> probably be too messy.

Maybe we could add callbacks into AM interface for 
send/receive/representation implementation of progress?
So AM would define a set of parameters to send into stat collector and 
show to users.

-- 
regards,
Andrey Lepikhov
Postgres Professional