On 2017-06-12 19:00:02 -0400, Tom Lane wrote: > Andres Freund <and...@anarazel.de> writes: > > On 2017-06-12 18:10:52 -0400, Tom Lane wrote: > >> it'd be worthwhile checking some actual examples rather than guessing. > > > It's indeed not very compact. E.g a simple example with small types: > > > CREATE TABLE partitioned(a int, b int, c timestamptz, data text) PARTITION > > BY RANGE (a, b, c); > > CREATE TABLE partitioned_child1 PARTITION OF partitioned FOR VALUES FROM > > (1, 1, '2017-01-01') TO (1, 1, '2017-02-01'); > > > postgres[6961][1]=# SELECT relname, pg_column_size(relpartbound), > > length(relpartbound), pg_column_size(pg_class) FROM pg_class WHERE > > relpartbound IS NOT NULL; > > ┌───────────────────────────────┬────────────────┬────────┬────────────────┐ > > │ relname │ pg_column_size │ length │ pg_column_size │ > > ├───────────────────────────────┼────────────────┼────────┼────────────────┤ > > │ partitioned_child1 │ 1355 │ 1351 │ 1523 │ > > │ partitioneded_list_committers │ 1130 │ 8049 │ 1298 │ > > └───────────────────────────────┴────────────────┴────────┴────────────────┘ > > So, counting on my fingers, you'd need something like twenty partitioning > columns before you hit trouble with the RANGE syntax.
Well, that's with 4/8 byte wide types. I'd be surprised if people only ever used those. I'd bet quite a bit that people will start using jsonb, postgis' geometry and such as partition types, even if it makes most of us cringe. > On the whole, I'm inclined to agree with Peter and Alvaro that this is > fine, at least for the short term. Even in the long term, I doubt we > need toastability, just a more compact representation than an expression > tree. bytea storage of an array, perhaps? Or maybe better, use anyarray > like we do in pg_statistic, so that it prints legibly. I'm not quite sure where the aversion to adding a toast table to pg_class is coming from? Why are we ok with arbitrary and hard to understand restrictions here, and not elsewhere? Greetings, Andres Freund -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
