摘要:
Provided are a method, system, and program for merging independent log entries in a multiple node shared nothing DBMS. Initially, log entries from multiple log entries are combined to form a single log entry sequence. Local transactions are generated from the single log entry sequence and stored in a local transactions structure. In particular, log entries with the same local transaction identifier form a local transaction. Then, local transactions having the same global identifier are merged to form global transactions.
摘要:
A globally unique transaction identifier for each transaction is recorded in log entries pursuant to a two-phase commit protocol, wherein multiple log entries in multiple database recovery logs that correspond to one transaction have a same globally unique transaction identifier. A causally ordered, ascending timestamp value is maintained in the log entries pursuant to the two-phase commit protocol. For each of the multiple database recovery logs, all the log entries related to a single transaction are marked identically with a mark unique to the single transaction in a given one of the database recovery logs. Global changes are identified for the single transaction from the log entries in the multiple database recovery logs based on the marking and the globally unique transaction identifier for each transaction by reading log entries based on the causally ordered, ascending timestamp value.