Unloading data with named pipes

You can use a named pipe to unload data from the database to external tables.

About this task

To use named pipes to unload data to external tables, follow these steps:

Procedure

  1. Specify the named pipe in the DATAFILES clause of either the CREATE EXTERNAL TABLE statement or the SELECT INTO EXTERNAL statement of SQL.
    DATAFILES ("PIPE:/usr/local/TAPE")
  2. Create the named pipes that you specified in the DATAFILES clause. Use operating-system commands to create the named pipes.
  3. Open the named pipes with a program that writes to the named pipe.
  4. Unload data to the named pipe.
    CREATE EXTERNAL TABLE emp_ext 
   ( name CHAR(18) EXTERNAL CHAR(20),
     hiredate DATE EXTERNAL CHAR(10),
     address VARCHAR(40) EXTERNAL CHAR(40),
     empno INTEGER EXTERNAL CHAR(6) )
   USING (
      FORMAT 'FIXED',
      DATAFILES 
      ("PIPE:/usr/local/TAPE")
       );

INSERT INTO emp_ext SELECT * FROM employee;

Results

Important: If you do not create and open the named pipes before you execute the SELECT or INSERT statement, the unload fails with the ENXIO error message (no such device or address).