This video describes the commit process. The virtual machine (Gem) places all new and changed objects on a fresh page in the Shared Page Cache (SPC). The Gem generates a preliminary transaction log record and passes it to the stone. The Gem requests the commit token from the stone. The Gem validates the “write set” by examining all commits that were made since the current transaction began to see if any subsequent transaction has conflicting modifications to any object. The Gem then checks locks to see if any other session has a lock on an object it wishes to write. If the checks succeed then a new commit record is created and passed to the stone. The stone then flushes the transaction log and informs the gem of the successful commit.

Advertisements