The DLTPCT parameter specifies the percentage of deleted records
a file can contain before you want the system to send a message to the system
history log (CRTPF, CHGPF, CRTSRCPF, and CHGSRCPF commands).
When a file is closed, the system checks the member to determine the percentage
of deleted records. If the percentage exceeds the value specified in the DLTPCT
parameter, a message is sent to the history log. (For information about processing
the history log, see the Control language (CL) topic. One reason
you might want to know when a file reaches a certain percentage of deleted
records is to reclaim the space used by the deleted records. After you receive
the message about deleted records, you can run the Reorganize Physical File
Member (RGZPFM) command to reclaim the space. You can also specify to bypass
the deleted records check by using the *NONE value for the DLTPCT parameter.
*NONE is the default for the DLTPCT parameter.
REUSEDLT parameter specifies
whether deleted record space should be reused on subsequent write operations
(CRTPF and CHGPF commands). When you specify *YES for the REUSEDLT parameter,
all insert requests on that file try to reuse deleted record space. Reusing
deleted record space allows you to reclaim space used by deleted records without
having to issue a RGZPFM command. When the CHGPF command is used to change
a file to reuse deleted records, it might take a long time to run, especially
if the file is large and there are already a lot of deleted records in it.
It is important to note the following items:
- The term arrival order loses its meaning for a file that reuses
deleted record space. Records are no longer always inserted at the end of
the file when deleted record space is reused.
- If a
new physical file is created with the reuse deleted record space attribute
and the file is keyed, the FIFO or LIFO access path attribute cannot be specified
for the physical file, nor can any keyed logical file with the FIFO or LIFO
access path attribute be built over the physical file.
- You cannot change an existing physical file to reuse deleted record space
if there are any logical files over the physical file that specify FIFO or
LIFO ordering for duplicate keys, or if the physical file has a FIFO or LIFO
duplicate key ordering.
- Reusing deleted record space should not be specified for a file that is
processed as a direct file or if the file is processed using relative record
numbers.