On Sat, Jan 18, 2020 at 6:18 PM Daniel Gustafsson <dan...@yesql.se> wrote: > Thanks again for reviewing (and working on the infrastructure required for > this > patch to begin with)! Regarding the persisting the progress; that would be a > really neat feature but I don't have any suggestion on how to do that safely > for real use-cases.
Leaving to one side the question of how much work is involved, could we do something conceptually similar to relfrozenxid/datfrozenxid, i.e. use catalog state to keep track of which objects have been handled and which not? Very rough sketch: * set a flag indicating that checksums must be computed for all page writes * use barriers and other magic to make sure everyone has gotten the memo from the previous step * use new catalog fields pg_class.relhaschecksums and pg_database.dathaschecksums to track whether checksums are enabled * keep launching workers for databases where !pg_class.dathaschecksums until none remain * mark checksums as fully enabled * party -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
