WAL: Insurance Against Disaster

Writing data to disk is expensive and relatively slow. If the database wrote every change straight into table files, performance would suffer. To combine speed and reliability (the D in ACID—Durability), PostgreSQL uses WAL (Write-Ahead Logging).

Full content is available with a subscription.
Get full access to all courses on the platform for one year with a single payment.
Unlike other platforms that charge per course, here you get everything for one price, and after one year of use there will be no automatic charge for the following year.