| 摘要 |
PROBLEM TO BE SOLVED: To provide a multimaster node type database management method capable of efficiently utilizing resources by achieving transaction discarding processing at a larger minimum value level without disturbing the consistency of the entire database. SOLUTION: An active transaction minimum value in a snap shot is notified from a lower-order master node to much higher-order master nodes, and the respective master nodes compare the transaction minimum value with a minimum value held by them to update a node minimum value and a cluster minimum value. The lower-order master node transmits a shadow copy of its own database, a heap tuple map expanded on its own memory and a transaction minimum value as a writing set, and a higher-order master node receiving the writing set updates a database by using the writing set when the transaction minimum value is equal to or larger than the cluster minimum value, and aborts the writing set when the transaction minimum value is smaller than the cluster minimum value. COPYRIGHT: (C)2013,JPO&INPIT |
