Databases & SQL

Write-Ahead Log

/raɪt əˈhed lɒɡ/

Definition

A journal (WAL) recording all changes before applying them to data files — enables crash recovery and replication.

Example in context

"PostgreSQL's WAL means if the server crashes mid-write, it replays the log on restart and recovers consistently."

Related terms

Practice this term

Master Write-Ahead Log in context by working through exercises in the Databases & SQL module. You'll see the term used in real engineering scenarios with multiple-choice, fill-in-the-blank, and matching drills.