On Mon, Dec 8, 2025 at 2:38 PM Amit Kapila <[email protected]> wrote: > > On Mon, Dec 8, 2025 at 10:25 AM Dilip Kumar <[email protected]> wrote: > > > > On Thu, Dec 4, 2025 at 4:20 PM Amit Kapila <[email protected]> wrote: > > > > > > On Thu, Dec 4, 2025 at 10:49 AM Dilip Kumar <[email protected]> wrote: > > > > > > > > > --- > > > > > I think the conflict history table should not be transferred to the > > > > > new cluster when pg_upgrade since the table definition could be > > > > > different across major versions. > > > > > > > > Let me think more on this with respect to behaviour of other factors > > > > like subscriptions etc. > > > > > > > > > > Can we deal with different schema of tables across versions via > > > pg_dump/restore during upgrade? > > > > > > > While handling the case of conflict_log_table option during pg_dump, I > > realized that the restore is trying to create conflict log table 2 > > different places 1) As part of the regular table dump 2) As part of > > the CREATE SUBSCRIPTION when conflict_log_table option is set. > > > > So one option is we can avoid dumping the conflict log tables as part > > of the regular table dump if we think that we do not need to conflict > > log table data and let it get created as part of the create > > subscription command, OTOH if we think we want to keep the conflict > > log table data, > > > > We want to retain conflict_history after upgrade. This is required for > various reasons (a) after upgrade DBA user will still require to > resolved the pending unresolved conflicts, (b) Regulations often > require keeping audit trails for a longer period of time. If a > conflict occurred at time X (which is less than the regulations > requirement) regarding a financial transaction, that record must > survive the upgrade, (c) > If something breaks after the upgrade (e.g., missing rows, constraint > violations), conflict history helps trace root causes. It shows > whether issues existed before the upgrade or were introduced during > migration, (d) as users can query the conflict_history tables, it > should be treated similar to user tables. > > BTW, we are also planning to migrate commit_ts data in thread [1] > which would be helpful for conflict_resolutions after upgrade. > > let it get dumped as part of the regular tables and in > > CREATE SUBSCRIPTION we will just set the option but do not create the > > table, > > > > Yeah, we can turn this option during CREATE SUBSCRIPTION so that it > doesn't try to create the table again. > > > although we might need to do special handling of this case > > because if we allow the existing tables to be set as conflict log > > tables then it may allow other user tables to be set, so need to think > > how to handle this if we need to go with this option. > > > > Yeah, probably but it should be allowed internally only not to users.
Yeah I wanted to do that, but problem is with dump and restore, I mean if you just dump into a sql file and execute the sql file at that time the CREATE SUBSCRIPTION with conflict_log_table option will fail as the table already exists because it was restored as part of the dump. I know under binary upgrade we have binary_upgrade flag so can do special handling not sure how to distinguish the sql executing as part of the restore or normal sql execution by user? > I think we can split this upgrade handling as a top-up patch at least > for the purpose of review. Make sense. -- Regards, Dilip Kumar Google
