Re: Restricting maximum keep segments by repslots

Andres Freund <andres@anarazel.de>

From: Andres Freund <andres@anarazel.de>

To: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>

Cc: peter.eisentraut@2ndquadrant.com, pgsql-hackers@postgresql.org

Date: 2017-11-06T13:20:50Z

Lists: pgsql-hackers

Hi,

On 2017-10-31 18:43:10 +0900, Kyotaro HORIGUCHI wrote:
>   - distance:
>     how many bytes LSN can advance before the margin defined by
>     max_slot_wal_keep_size (and wal_keep_segments) is exhasuted,
>     or how many bytes this slot have lost xlog from restart_lsn.

I don't think 'distance' is a good metric - that's going to continually
change. Why not store the LSN that's available and provide a function
that computes this? Or just rely on the lsn - lsn operator?

- Andres

Commits

Save slot's restart_lsn when invalidated due to size
- 12e52ba5a76e 13.0 landed
- 0188bb82531f 14.0 landed
Fix checkpoint signalling
- 1816a1c6ffe4 13.0 landed
Check slot->restart_lsn validity in a few more places
- d0abe78d8427 13.0 landed
Allow users to limit storage reserved by replication slots
- c6550776394e 13.0 landed
Remove header noise from test_decoding test
- 69360b34589b 13.0 landed
Rework WAL-reading supporting structs
- 709d003fbd98 13.0 cited
Flip argument order in XLogSegNoOffsetToRecPtr
- a22445ff0be2 12.0 cited