On Wed, Jul 20, 2022 at 11:35 AM Greg Stark <st...@mit.edu> wrote: > On the one hand the rest of Postgres seems to be designed on the > assumption that the number of tables and database objects is limited > only by disk space. The catalogs are stored in relational storage > which is read through the buffer cache. On the other hand it's true > that syscaches don't do expire entries (though I think the assumption > is that no one backend touches very much). > > It seems like if we really think the total number of database objects > is reasonably limited to scales that fit in RAM there would be a much > simpler database design that would just store the catalog tables in > simple in-memory data structures and map them all on startup without > doing all the work Postgres does to make relational storage scale. >
I think efforts to do such a thing have gotten caught up in solving issues around visibility and managing the relationship between local and global caches [1]. It doesn't seem like the primary technical concern was memory usage. [1] https://www.postgresql.org/message-id/flat/4E72940DA2BF16479384A86D54D0988A567B9245%40G01JPEXMBKW04
