Locking Methods (Magic xpa 4.x)

If a transaction cannot open a table or record at runtime, because of a potential conflict with another transaction, Magic xpa will continue trying to open the table or record that is currently locked. While waiting for access, Magic xpa will display a message informing the end user that the table or record is currently locked. Magic xpa’s attempt to enter the table or record ends when either the end user presses Exit (ESC) to abort the task, or when the transaction of the other user ends the transaction. Note that if the transactions of both users were non-conflicting, neither would have to wait to gain access to the table or record.

Magic xpa implements two kinds of locking methods: Database locks and Magic xpa locks.

• A database lock is a lock that uses the methods specified by the specified DBMS. For example, using SELECT…FOR UPDATE in Oracle and SELECT…UPDLOCK in MSSQL.

• A Magic xpa lock uses the mglock to perform its logical locking method.