Multi-Version Concurrency Control (MVCC) in Non-Volatile Memory

A system, comprising:

• a memory;
• and
• at least one processor coupled to the memory and configured to:
• determine that an event occurred, wherein one or more write transactions to one or more records of a multi-version database that were pending prior to the event did not contain, and wherein the multi-version database is stored in a non-volatile memory;
• identify the one or more write transactions based on a commit value that was stored in the non-volatile memory prior to the event, wherein each of the one or more write transactions includes a commit value;
• select a particular one of the identified uncommitted write transactions;
• identify, from the multi-version database, a first version of a record corresponding to the selected uncommitted write transaction, wherein the first version was not committed;
• identify an earlier version of the record that was committed prior to the event;
• and
• set a visibility of the record to indicate that the earlier version of the record is visible and the first version of the record is not visible.

A non-transitory computer-readable device having instructions stored thereon that, when executed by at least one computing device, causes the at least one computing device to perform operations comprising:

• determining that an event occurred, wherein one or more write transactions to one or more records of a multi-version database that were pending prior to the event did not commit, and wherein the multi-version database is stored in a non-volatile memory;
• identifying the one or more write transactions based on a commit value that was stored in the non-volatile memory prior to the event, wherein each of the one or more write transactions includes a commit value;
• selecting a particular one of the identified uncommitted write transactions;
• identifying, from the multi-version database, a first version of a record corresponding to the selected uncommitted write transaction, wherein the first version was not committed;
• identifying an earlier version of the record that was committed prior to the event;
• and
• setting a visibility of the record to indicate that the earlier version of the record is visible and the first version of the record is not visible.