File Management - IBM

number wraps back to 1.00 and continues to increment unless you specify the
SRCOPT and SRCSEQ parameters on the copy command.
If several copies to the same file are made with MBROPT(*ADD), you will have
duplicate sequence numbers in the file. You can correct this using the Reorganize
Physical File Member (RGZPFM)command.
Date fields are initialized to zeros.
When copying to or from a device, it is more efficient to use a device data file than
a device source file. The copy function automatically adds or removes sequence
number fields and date fields source sequence number and date fields as necessary.
Copying database source files to device source files
When you are copying to a device source file, the system removes the date fields
and the sequence number fields from the start of the records.
When copying to or from a device, it is more efficient to use a device data file than
a device source file. The copy function automatically adds or removes source
sequence number fields and date fields as necessary.
Copying database source files to database source files
You can copy between database source files by using the CPYSRCF or CPYF
command. The CPYSRCF command may be easier to use because the parameter
defaults are better suited for copying database source files.
If you specify SRCOPT(*SEQNBR) to update the sequence numbers, the system
considers the SRCSEQ parameter. The SRCSEQ parameter specifies the starting
value that is assigned to the first record that is copied and the increment value.
The defaults are 1.00 and 1.00. You can specify a whole number of no more than 4
digits or a fraction of no more than 2 digits for the starting value and the
increment value. (You must use a decimal point for fractions.)
For example, if you specify SRCSEQ(100.50), then the records copied will have
sequence numbers 100.00, 100.50, 101.00, 101.50, and so on.
Suppose that you have a file that contains more than 9999 records. Use a fractional
increment value so that each record has a unique sequence number. If you specify
a starting value of .01 and an increment value of .01, the maximum number of
records copied with unique sequence numbers is 999 999. When the maximum
sequence number is exceeded (9999.99), all remaining records on that copy are
initialized to 9999.99. The system does not wrap back to 1.00.
If the database source file that you are copying to has only an arrival sequence
access path, the records are always physically placed at the end of the file.
(Because the file does not have a keyed sequence access path, you cannot insert
records into the middle of the file keyed access path.)
Chapter 4. Copying files 121