PostgreSQL's isolation levels hold surprises: read uncommitted silently becomes read committed, repeatable read forbids phantom reads the standard permits, and…

PostgreSQL's `DEFERRABLE` transaction mode only works with `SERIALIZABLE READ ONLY` transactions, where it waits for a safe snapshot to eliminate…

PostgreSQL 19 switches TOAST compression from pglz to lz4 by default—faster, more efficient, and finally the right call.

PostgreSQL forbids indexing with the default text search configuration because it's mutable—change the setting, and your index silently disagrees with reality.

Default_tablespace quietly routes tables and indexes to alternate storage — but three quirks can surprise you, and tablespaces themselves are mostly…

PostgreSQL's table access method interface lets you plug in alternative storage engines.

Raise `default_statistics_target` from 100 to 500 and ANALYZE slows down forever — but sometimes that's the right call.

Query planning is a two-job problem: rewrite your SQL into a better shape, then search billions of possible join orders for the cheapest one.

PostgreSQL's dozen `debug_` parameters are its own testing machinery, exposed as runtime settings.

PostgreSQL's `deadlock_timeout` controls how often deadlocks are searched for, not how long a deadlock will be tolerated.