On Wed, Mar 1, 2023 at 9:47 AM Jacob Champion <jchamp...@timescale.com> wrote: > > Hi, > > I'm going to register this in CF for feedback. > > Summary for potential reviewers: we don't use declarative partitions in > the Timescale partitioning scheme, but it'd be really nice to be able to > replicate between our tables and standard tables, or between two > Timescale-partitioned tables with different layouts. This patch lets > extensions (or savvy users) upgrade an existing inheritance relationship > between two tables into a "logical partition" relationship, so that they > can be handled with the publish_via_partition_root machinery. > > I hope this might also help pg_partman users migrate between old- and > new-style partition schemes, but that's speculation. >
OK, my understanding is that TimescaleDB uses some kind of quasi-partitioned/inherited tables (aka hypertables? [1]) internally, and your proposed WIP patch provides a set_logical_root() function which combines with the logical replication (LR) PUBLICATION option "publish_via_partition_root" to help to replicate those. You also mentioned pg_partman. IIUC pg_partman is a partitioning extension [2] that pre-dated the native PostgreSQL partitioning introduced in PG10 (i.e. quite a while ago). I guess it would be a very niche group of users that are still using pg_partman old-style (pre-PG10) partitions and want to migrate them but have not already done so. Also, the pg_partman README [3] says since v4.0.0 there is extensive support for native PostgreSQL partitions, so perhaps existing LR already works for those. Outside the scope of special TimescaleDB tables and the speculated pg_partman old-style table migration, will this proposed new feature have any other application? In other words, do you know if this proposal will be of any benefit to the *normal* users who just have native PostgreSQL inherited tables they want to replicate? I haven’t yet looked at the WIP patch TAP tests – so apologies for my question if the benefits to normal users are self-evident from your test cases. ------ [1] https://docs.timescale.com/use-timescale/latest/hypertables/about-hypertables/ [2] https://www.crunchydata.com/blog/native-partitioning-with-postgres [3] https://github.com/pgpartman/pg_partman Kind Regards, Peter Smith. Fujitsu Australia
