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AdministeringIn addition to administering the database server, you can tune performance, replicate data, and archive data.
System administrationThese topics contain concepts, procedures, and reference information for database and database server administrators to use for managing and tuning HCL OneDB™ database servers.
Administrator's GuideThe HCL OneDB™ Administrator's Guide provides the information required to administer HCL OneDB™.
Disk, memory, and process management
Moving data with external tablesYou can use external tables to load and unload database data.
Load data from and unload to a named pipeYou can use a named pipe, also called a first-in-first-out (FIFO) data file, to load from and unload to a nonstandard device, such as a tape drive.
FIFO virtual processorsThe database server uses FIFO virtual processors (VPs) to read and write to external tables on named pipes.

FIFO virtual processors

The database server uses FIFO virtual processors (VPs) to read and write to external tables on named pipes.

The default number of FIFO virtual processors is 1.

The database server uses one FIFO VP for each named pipe that you specify in the DATAFILES clause of the CREATE EXTERNAL TABLE statement. For example, suppose you define an external table with the following SQL statement:

CREATE EXTERNAL TABLE ext_items
   SAMEAS items
   USING (
      DATAFILES("PIPE:/tmp/pipe1",
                "PIPE:/tmp/pipe2",
                "PIPE:/tmp/pipe3"
      ));

If you use the default value of 1 for FIFO VPs, the database server does not read from pipe2 until it finishes reading all the data from pipe1, and does not read from pipe3 until it finishes reading all the data from pipe2.