Begins an explicit transaction.
If a transaction is aborted, all writes made since the beginning of a transaction are cancelled, and all files are returned to the state they were in before the transaction began.
TTS Abort Transaction releases the following record locks:
Physical record locks generated by the file server when an application tried to write to an unlocked record
Physical or logical locks that have not been released because of a file write
For explicit transactions, the transaction is backed out; any locks being held are released.
For implicit transactions, if the number of logical or physical records still locked exceeds the threshold, TTS Abort Transaction returns Transaction Restart (0xFE), the transaction is backed out, and the file server automatically starts a new implicit transaction.