[anarazel]

> It even assists in PostgreSQL’s implementation of Multiversion Concurrency Control (MVCC) - the WAL keeps a version history of data changes,

That's not really correct - postgres' MVCC implementation doesn't read from the WAL. Sure, row changes are WAL logged, but that's not really related to MVCC.

[jacobprall]

That's an excellent point. My statement was unnecessarily confusing. I've changed it to simply reference another benefit of the WAL - optimizing I/O operations. That would make a good blog post in and of itself :D