Microsoft Technology Licensing, LLC

Mike Zwilling

Cristian Diaconu

Per-Ake Larson

The subject disclosure relates to a database recovery technique that implements various aspects of transaction logging to optimize database recovery performance. Transactions are logged logically with no reference to physical location, which enables logging to be performed via multiple independent log streams in parallel. A set of log streams can further be adjusted to conform to a local configuration of a mirror or secondary node in order to increase mirroring flexibility. Additionally, individual transactions or groups of transactions are recorded using a single log record, which contains timestamp information to enable database recovery without reference to physical checkpoint files. Further, techniques are provided herein for processing transactions without Write Ahead Logging or hardening of undo information. As further described herein, a transaction can be committed via a set of hierarchical stages, which in turn can facilitate integration of an in-memory database system with one or more external database systems.

Versatile in-memory database recovery using logical log records

The subject disclosure relates to a distributed transaction management technique that ensures synchronization between participating nodes in a global or distributed database transaction. The technique leverages a commit protocol that uses local clocks at the respective participating nodes. Participants in a global transaction are configured to utilize the same commit timestamp and logical read time and can advance their respective local clocks to establish this synchronization. In one embodiment, distributed commit utilizes a modified version of two-phase commit that includes an extra phase to collect commit timestamp votes from participants. Additionally, a heartbeat mechanism can be used to establish loose synchronization between nodes. In another embodiment, a node can respond to a remote transaction request by returning a list of nodes involved in generating the result of the transaction and the types of access used by such nodes in addition to the transaction result itself.

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Redmond, WA, United States of America

Mike Zwilling