Durability

Last week, I covered how MVCC, Postgres’s storage system, works on a very high level. Near the end, I also mentioned that it doesn’t quite lend itself well to certain use cases, such as rapidly mutating session storage. Well, there is one caveat to that statement that I’d forgotten about because of its relatively limited utility: unlogged tables. Here’s what the Postgres documentation has to say about unlogged tables: Data written to unlogged tables is not written to the write-ahead log, which makes them considerably faster than ordinary tables.