Algorithms for flexible space management in transaction systems supporting fine-granularity locking
We present several methods which relate to space management in a transaction system supporting fine-granularity (e.g., record) locking. These methods enable varying length records to be supported efficiently by permitting garbage collection to be performed within a page without the moved records having to be locked or the movements having to be logged. We present methods to do the following: (1) When a transaction releases space, efficiently prevent that space from being consumed by other transactions until that transaction terminates, while allowing the same transaction to reuse the space it freed. (2) Under the correct circumstances, avoid reading a totally empty deallocated page from disk during page reallocation. (3) Updating and logging of free space inventory pages' (FSIPs') changes for correct recovery. (4) Reduce locking during a table scan by a transaction using the isolation level of cursor stability. Our methods improve concurrency and space utilization, and provide I/O and CPU savings. Our space reservation and FSIP logging methods have been implemented in DB2 V3 in preparation for DB2's support of record locking.
Unable to display preview. Download preview PDF.
- Astr76.Astrahan, M., et al. System R: Relational Approach to Data Base Management, ACM Transactions on Database Systems, Vol. 1, No. 2, June 1976.Google Scholar
- CrHT90.Crus, R., Haderle, D., Teng, J. Method for Minimizing Locking and Reading in a Segmented Storage Space, U.S. Patent 4,961,134, IBM, October 1990.Google Scholar
- HaSe89.Haderle, D., Seppi, K. Mass Delete of Index Structures, IBM Technical Disclosure Bulletin, August 1989.Google Scholar
- LiMP86.Lindsay, B., Mohan, C., Pirahesh, H. Method for Reserving Space Needed for “Rollback” Actions, IBM Technical Disclosure Bulletin, Vol. 29, No. 6, November 1986.Google Scholar
- LiMR90.Lindsay, B., Mohan, C., Rodriguez, R.A. Method for Updating Free Space Allocation Records in 0S/2 DBM Table Data Files, IBM Technical Disclosure Bulletin, Vol. 33, No. 6A, November 1990.Google Scholar
- MHLPS92.Mohan, C., Haderle, D., Lindsay, B., Pirahesh, H., Schwarz, P. ARIES: A Transaction Recovery Method Supporting Fine-Granularity Locking and Partial Rollbacks Using Write-Ahead Logging, ACM Transactions on Database Systems, Vol. 17, No. 1, March 1992.Google Scholar
- Moha90a.Mohan, C. Commit_LSN: A Novel and Simple Method for Reducing Locking and Latching in Transaction Processing Systems, Proc. 16th International Conference on Very Large Data Bases, Brisbane, August 1990.Google Scholar
- Moha90b.Mohan, C. ARIES/KVL: A Key-Value Locking Method for Concurrency Control of Multiaction Transactions Operating on B-Tree Indexes, Proc. 16th International Conference on Very Large Data Bases, Brisbane, August 1990. A different version of this paper is available as IBM Research Report RJ7008, IBM Almaden Research Center, September 1989.Google Scholar
- Moha93a.Mohan, C. IBM's Relational DBMS Products: Features and Technologies, Proc. SIGMOD International Conference on Management of Data, Washington, May 1993.Google Scholar
- Moha93b.Mohan, C. A Cost-Effective Method for Providing Improved Data Availability During DBMS Restart Recovery After a Failure, Proc. 19th International Conference on Very Large Data Bases, Dublln, August 1993.Google Scholar
- Moha93c.Mohan, C. Transaction Processing System and Method With Reduced Locking, United States Patent 5,247,672, IBM, September 1993.Google Scholar
- MoLe92.Mohan, C., Levine, F. ARIES/IM: An Efficient and High Concurrency Index Management Method Using Write-Ahead Logging, Proc. ACM SIGMOD International Conference on Management of Data, San Diego, June 1992. A longer version of this paper is available as IBM Research Report RJ6846, IBM Almaden Research Center, August 1989.Google Scholar
- Sert91.Serlin, O. The History of DebitCredit and the TPC, Chapter 2 in The Benchmark Handbook for Database and Transaction Processing Systems, J. Gray (Ed.), Morgan Kaufmann Publishing, Inc., 1991.Google Scholar