Serializable Snapshot Isolation in PostgreSQL
Abstract
This paper describes our experience implementing PostgreSQL's new serializable isolation level. It is based on the recently-developed Serializable Snapshot Isolation (SSI) technique. This is the first implementation of SSI in a production database release as well as the first in a database that did not previously have a lock-based serializable isolation level. We reflect on our experience and describe how we overcame some of the resulting challenges, including the implementation of a new lock manager, a technique for ensuring memory usage is bounded, and integration with other PostgreSQL features. We also introduce an extension to SSI that improves performance for read-only transactions. We evaluate PostgreSQL's serializable isolation level using several benchmarks and show that it achieves performance only slightly below that of snapshot isolation, and significantly outperforms the traditional two-phase locking approach on read-intensive workloads.
- Publication:
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arXiv e-prints
- Pub Date:
- August 2012
- DOI:
- 10.48550/arXiv.1208.4179
- arXiv:
- arXiv:1208.4179
- Bibcode:
- 2012arXiv1208.4179P
- Keywords:
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- Computer Science - Databases
- E-Print:
- VLDB2012