OCC and PCC (subject modified by moderator)

1)Explain OCC & PCC (optimistic concurrency control , Pessimistic concurrency control)

Hi,

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Coming to your query, OCC was introduced since AX 4.0. See here (http://blogs.msdn.com/b/emeadaxsupport/archive/2009/07/08/occ-vs-pcc-in-queries-rcsi-preventing-locking-and-blocking-effects-on-the-sql-server-transaction-log-update-recordset.aspx) for differences.