| IBASE_DEFAULT | The default transaction settings are to be used. This default is
       determined by the client library, which defines it as
       IBASE_WRITE|IBASE_CONCURRENCY|IBASE_WAIT in most cases. | 
      
       | IBASE_READ | Starts a read-only transaction. | 
      
       | IBASE_WRITE | Starts a read-write transaction. | 
      
       | IBASE_CONSISTENCY | Starts a transaction with the isolation level set to
       'consistency', which means the transaction cannot read from tables
       that are being modified by other concurrent transactions. | 
      
       | IBASE_CONCURRENCY | Starts a transaction with the isolation level set to
       'concurrency' (or 'snapshot'), which means the transaction 
       has access to all tables, but cannot see changes that were committed
       by other transactions after the transaction was started. | 
      
       | IBASE_COMMITTED | Starts a transaction with the isolation level set to
       'read committed'. This flag should be combined with either
       IBASE_REC_VERSION or 
       IBASE_REC_NO_VERSION. This isolation level
       allows access to changes that were committed after the transaction
       was started. If IBASE_REC_NO_VERSION was
       specified, only the latest version of a row can be read. If 
       IBASE_REC_VERSION was specified, a row can
       even be read when a modification to it is pending in a concurrent
       transaction. | 
      
       | IBASE_WAIT | Indicated that a transaction should wait and retry when a
       conflict occurs. | 
      
       | IBASE_NOWAIT | Indicated that a transaction should fail immediately when a
       conflict occurs. |