On Tue, Jun 28, 2022 at 05:32:26PM -0700, Peter Geoghegan wrote: > The main enhancement to VACUUM for Postgres 15 was item 1, which > taught VACUUM to dynamically track the oldest remaining XID (and the > oldest remaining MXID) that will remain in the table at the end of the > same VACUUM operation. These final/oldest XID/MXID values are what we > now use to set relfrozenxid and relminmxid in pg_class. Previously we > just set relfrozenxid/relminmxid to whatever XID/MXID value was used > to determine which XIDs/MXIDs needed to be frozen. These values often > indicated more about VACUUM implementation details (like the > vacuum_freeze_min_age GUc's value) than the actual true contents of the > table at the end of the most recent VACUUM. > > It might be worth explaining the shift directly in the release notes. > The new approach is simpler and makes a lot more sense -- why should > the relfrozenxid be closely tied to freezing? We don't necessarily
I don't think this is an appropriate detail for the release notes. -- Bruce Momjian <br...@momjian.us> https://momjian.us EDB https://enterprisedb.com Indecision is a decision. Inaction is an action. Mark Batterson
