PostgreSQL pattern-matches a hash join’s compiled expression steps and swaps the general-purpose interpreter for a specialised C function, which is worth up to 20% on probe-heavy …
PostgreSQL’s wait ladder spins in user space, then backs off with a jittered exponential delay so spinners don’t convoy, and only then blocks in the kernel — and it learns how long …
PostgreSQL 20 moved buffer content locks out of the LWLock machinery and into the buffer’s own 64-bit state word, so taking one costs a single compare-and-swap.
palloc quantises sizes to powers of two, keeps eleven freelists, carves dying blocks into reusable chunks, and recycles memory contexts so a per-tuple context costs zero mallocs.
Committing doesn’t fsync: backends copy WAL into shared memory and piggyback on one fsync, using LWLockAcquireOrWait so followers can observe someone else’s flush without ever …