txn abort  

The txn abort command causes an abnormal termination of the transaction.

The log is played backward, and any necessary recovery operations are performed. After recovery is completed, all locks held by the transaction are acquired by the parent transaction in the case of a nested transaction, or released in the case of a non-nested transaction. As is the case for txn commit, applications that require strict two-phase locking should not explicitly release any locks.

In the case of nested transactions, aborting the parent transaction causes all children of that transaction to be aborted.

After txn abort has been called, regardless of its return, the txn handle may not be accessed again.

The txn abort command returns 0 on success, and in the case of error, a Tcl error is thrown.