Class RowLockingRR

  • All Implemented Interfaces:
    LockingPolicy
    Direct Known Subclasses:
    RowLocking2

    public class RowLockingRR
    extends RowLocking3
    A locking policy that implements row level locking with repeatable read isolation. Since phantom protection with previous key locking is actually handled by the upper level access methods, the only difference in repeatable read is that read locks are of type RowLock.RS2. This type will not conflict with a previous key insert lock.
    See Also:
    LockingPolicy
    • Constructor Detail

      • RowLockingRR

        protected RowLockingRR​(LockFactory lf)
    • Method Detail

      • getReadLockType

        protected RowLock getReadLockType()
        Description copied from class: RowLocking3
        Get type of lock to get while reading data.

        This routine is provided so that class's like RowLockingRR can override just this routine to get RS2 locks vs RS3 locks, and still reuse all the other code in this class.

        Overrides:
        getReadLockType in class RowLocking3
        Returns:
        The lock type of a shared lock for this locking policy.
      • getUpdateLockType

        protected RowLock getUpdateLockType()
        Description copied from class: RowLocking3
        Get type of lock to get while requesting "update" lock.

        This routine is provided so that class's like RowLockingRR can override just this routine to get RU2 locks vs RU3 locks, and still reuse all the other code in this class.

        Overrides:
        getUpdateLockType in class RowLocking3
        Returns:
        The lock type of a shared lock for this locking policy.
      • getWriteLockType

        protected RowLock getWriteLockType()
        Description copied from class: RowLocking3
        Get type of lock to get while writing data.

        This routine is provided so that class's like RowLockingRR can override just this routine to get RX2 locks vs RX3 locks, and still reuse all the other code in this class.

        Overrides:
        getWriteLockType in class RowLocking3
        Returns:
        The lock type of a shared lock for this locking policy.
      • unlockRecordAfterRead

        public void unlockRecordAfterRead​(Transaction t,
                                          ContainerHandle container_handle,
                                          RecordHandle record,
                                          boolean forUpdate,
                                          boolean row_qualified)
                                   throws StandardException
        Unlock a record after it has been locked for read.

        In repeatable read only unlock records which "did not qualify". For example in a query like "select * from foo where a = 1" on a table with no index it is only necessary to hold locks on rows where a=1, but in the process of finding those rows the system will get locks on other rows to verify they are committed before applying the qualifier. Those locks can be released under repeatable read isolation.

        Specified by:
        unlockRecordAfterRead in interface LockingPolicy
        Overrides:
        unlockRecordAfterRead in class NoLocking
        Throws:
        StandardException - Standard exception policy.
        See Also:
        Page