File Management - IBM

them on to the to-file. The system then deletes the temporary file when the
copy function from the temporary file to the database or DDM files completes.
Parallel data loader support to use with the CPYFRMIMPF
command
The Copy From Import File (CPYFRMIMPF) supports copying the data in parallel
from an import file to a to-file using multiple jobs during the copy. This allows
you to copy data files from other platforms into a to-file quickly and easily. This is
especially useful for those who use data warehousing. To use multiple jobs, your
system must have the Symmetric Multiprocessing Product (SMP).
The number of jobs you use during the copy is determined by the
DEGREE(*NBRTASKS) parameter of the Change Query Attributes (CHGQRYA)
command. If the from-file has less than 50,000 records, only one job will be used
regardless of the *NBRTASKS value.
The CPYFRMIMPF command (with the parallel data loader support) essentially
breaks the import file into smaller portions or blocks. Each of these smaller
portions is submitted in parallel, so the entire file processes at the same time. (This
eliminates the latency of sequential processing.)
To maintain the same relative record numbers of the from-file in the to-file, use
only one job for the copy. Specify DEGREE(*NONE).
Handling data from the import file
The Copy From Import File (CPYFRMIMPF) reads data from an import file and
copies the data to a to-file. The data of the import file can be formatted by
delimiters or in a fixed format.
A “Delimited import file” has a series of characters (delimiters) that define where
fields begin and end. The parameters of the command define which characters are
used for delimiters.
A “Fixed formatted import file” on page 145 requires the user to define a Field
Definition File that defines the format of the import file. The Field Definition File
defines where fields begin, end, and are null.
Delimited import file
The following characters and data types interpret the import file’s data for a
delimited import file:
Blanks
Blanks are treated in the following ways:
v All leading and trailing blanks are discarded for character fields unless
enclosed by string delimiters.
v A field of all blanks is interpreted as a null field for character data.
v You cannot embed blanks within numeric fields.
v You cannot select a blank as a delimiter.
Null Fields
A null field is defined as:
Chapter 4. Copying files 143