Advanced MySQL 8

Writeset

The writeset of a transaction is a set of hashes that identify each row in the database changed by it. It contains the hash for the row's primary keys that are changed, and in some cases, the hashes of foreign keys or other dependencies that need to be captured. (for example, non-null unique keys; writesets are generated during the execution of a transaction and are used to parallelize transactions that modify disjoint sets.

We demonstrate the Write set parallelism in the following diagram:

Writesets are used by group replication to detect which read-write transactions can run in parallel among member servers using the certification ...