POSTGRES WRITE-AHEAD LOGS

Summary from the TLDR Web Dev newsletter

Postgres Write-Ahead Logs (WAL) are needed for logical replication in Postgres. WAL works by storing each state change as a command in an append-only file before the change is actually made to the database, allowing for recovery from the last checkpoint in case of a crash. WAL offers various configurable parameters like `wal_level`, `fsync`, `wal_buffers`, and `checkpoint_flush_after` to optimize performance and control data retention.