On 06/12/2013 07:01 AM, Tatsuo Ishii wrote: >>>> Please explain what you mean by the word "true" used here. >>> In another word, "eager replication". >> Do you mean something along these lines : >> >> "Most synchronous or eager replication solutions do conflict prevention, >> while asynchronous solutions have to do conflict resolution. For instance, >> if a record is changed on two nodes simultaneously, an eager replication >> system would detect the conflict before confirming the commit and abort >> one of the transactions. A lazy replication system would allow both >> transactions to commit and run a conflict resolution during >> resynchronization. " >> >> ? > > No, I'm not talking about conflict resolution. > > From http://www.cs.cmu.edu/~natassa/courses/15-823/F02/papers/replication.pdf: > ---------------------------------------------- > Eager or Lazy Replication? > Eager replication: > keep all replicas synchronized by updating all > replicas in a single transaction > > Lazy replication: > asynchronously propagate replica updates to > other nodes after replicating transaction commits > ----------------------------------------------
OK, so you mean it's *globally* synchronous, perhaps using something like 2PC. All replicas get the transaction and apply it or none do. Right? -- Craig Ringer http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
