Two-pass multi-version read consistency

摘要: The present invention describes a method and apparatus that forces all parts of an update transaction to commit automatically using two-phase commit. uses the messages negotiate system number (SCN) is then recorded on each nodes as logical point in time distributed committed. scheme consists "prepare" phase "commit" phase. database environment involves multiple participants (databases). In prepare phase, one N selected "commit point." includes log into which information written states has remaining N-1 enter "prepare phase." lock their databases state they are ready roll back or transaction. mid-point at (nth participant) writes its log. second informed release locks have been set.