On Wed, Apr 24, 2024 at 04:17:44PM +0900, Michael Paquier wrote: > - Support ALTER TABLE .. SET LOGGED/UNLOGGED for partitioned tables, > where the command only works on partitioned tables so that's only a > catalog switch.
I'm not following what this means. Does SET [UN]LOGGED on a partitioned table recurse to its partitions? Does this mean that you cannot changed whether a single partition is [UN]LOGGED? How does this work with sub-partitioning? > - CREATE TABLE PARTITION OF would make a new partition inherit the > logged ness of the parent if UNLOGGED is not directly specified. This one seems generally reasonable to me, provided it's properly noted in the docs. > - How about ONLY? Would it make sense to support it so as ALTER TABLE > ONLY on a partitioned table does not touch any of its partitions? > Would not specifying ONLY mean that the loggedness of the partitioned > table and all its partitions is changed? That would mean a burst in > WAL when switching to LOGGED, which was a concern when this feature > was first implemented even for a single table, so for potentially > hundreds of them, that would really hurt if a DBA is not careful. I guess ONLY could be a way of changing the default for new partitions without changing whether existing ones were logged. I'm not tremendously concerned about the burst-of-WAL problem. Or, at least, I'm not any more concerned about it for partitioned tables than I am for regular tables. I do wonder if we can improve the performance of setting tables LOGGED, but that's for a separate thread... > - CREATE TABLE does not have a LOGGED keyword, hence it is not > possible through the parser to force a partition to have a permanent > persistence even if its partitioned table uses UNLOGGED. Could we add LOGGED for CREATE TABLE? -- Nathan Bossart Amazon Web Services: https://aws.amazon.com