2.2.4.4.2 Out-of-Band Attention Signal

In this example, a SQL statement is sent to the server; however, before all the data has been returned, an interrupt or Attention signal is sent to the server. The client reads and discards any data received between the time the interrupt was sent and the interrupt acknowledgment was received. The interrupt acknowledgment from the server is a bit that is set in the status field of the DONE token.

 Client:    select name, empid from employees
  
 Server:    COLNAME   data stream
            COLFMT        datastream
            ROW           data stream
            .
            .
            ROW           data stream
  
 Client:    ATTENTION SENT

The client reads and discards any data from the server until a DONE_ATTN acknowledgment is received.

 Server:    DONE          data stream (with DONE_ATTN bit set)