PostgreSQL Allocates Memory Fast
Every C program that wants to be fast needs to be fast at allocating memory. PostgreSQL allocates memory in the tightest loop imaginable: a hash join probes its hash table once per …
Performance
PostgreSQL Groups Commits
Every database has a moment where a transaction becomes durable, and every database has to decide what that moment costs. PostgreSQL’s answer is unusual: committing a transaction …
tmux Batches Terminal Output: One Write() Per Event Loop Iteration
Every byte tmux sends to a terminal goes through one function that appends to a per-client buffer, and that buffer is flushed with a single write() per event loop iteration.
PostgreSQL Computes Page Checksums Fast
Every page PostgreSQL writes to disk gets a checksum: two bytes in the page header that let the server notice, on the next read, that the page it just read is not the page it …
PostgreSQL Deduplicates B-Tree Entries
Every index is a lie about multiplicity. A CREATE INDEX on a boolean column produces a structure in which, logically, there are only two distinct keys — but the index has to be …