Implementation of PITR for PG18

[schmidt-scaled]

[boddumanohar]

Had a few questions during implementation PTIR for branch clones and here are the answers from the team. Documenting this discussion in this comment.

1. What should be the default volume size, IOPS of a WAL PVC?

Capacity: Its hard for me to estimate, given that we take periodic snapshots with default interval of every 30mins, It's better we would rather err on the upper side for now and make it big

About IOPS, we could split the assigned IOPS and provide 25% for the WAL and 75% for the data volume.

2. Under used_resources section of the branch, should we also add the size of the WAL PVC?

Yes

3. When a branch has PITR enabled, then all its clones and clones from backups with also have PITR enabled. Because the PGDATA and PGWAL are initialised in a separate folder.

When we clone a branch, if the target branch doesn't need PITR, we disable continuous periodic snapshots. Also care should be taken that we sequentially clone the Data volume first and then the PGWAL directory.