Loading data with named pipes

You can use a named pipe to load data from external tables.

About this task

To use a named pipe to load data from an external table, follow these steps:

Procedure

  1. Specify the named pipes in the DATAFILES clause of the CREATE EXTERNAL TABLE statement in SQL.
  2. Create the named pipes that you specified in the DATAFILES clause.
    Use operating-system commands to create the named pipes.

    Use the mknod UNIX command with the -p option to create a named pipe. To avoid blocking open problems for pipes on UNIX, start separate UNIX processes for pipe-readers and pipe-writers or open the pipes with the O_NDELAY flag set.

  3. Open the named pipes with a program that reads the named pipe.
  4. Execute the INSERT statement in SQL.
    INSERT INTO employee SELECT * FROM emp_ext;

Results

Important: If you do not create and open the named pipes before you execute the INSERT statement, the INSERT succeeds, but no rows are loaded.