A commit preserve the changes by creating a new version of the data.
See also: wiki/Two-phase_commit_protocol
A commit occurs by appending a special record into the WAL.
A commit request that the changes in the transaction be made permanent.
Changes made by the transaction are permanent and visible to other users only after a transaction commits.
Changes mad prior to any commit event are in a sort of staging area.
A commit ends the current transaction and makes permanent all changes performed in the transaction.
Two-phase commit in a distributed environment.
An Atomic commit means that either all changes within a single transaction occur or none of them occur. Atomic Commit