The considerations apply for opening files when sequential-only
processing is specified. If the system determines that sequential-only processing
is not allowed, a message is sent to the program to indicate that the request
for sequential-only processing is not being accepted; however, the file is
still opened for processing.
- If the program opened the member for output only, and if SEQONLY(*YES)
was specified (number of records was not specified) and either the opened
member is a logical member, a uniquely keyed physical member, or there are
other access paths to the physical member, SEQONLY(*YES) is changed to SEQONLY(*NO)
so the program can handle possible errors (for example, duplicate keys, conversion
mapping, and select/omit errors) at the time of the output operation. If you
want the system to run sequential-only processing, change the SEQONLY parameter
to include both the *YES value and number of records specification.
- Sequential-only processing can be specified only for input-only (read)
or output-only (add) operations. If the program specifies update or delete
operations, sequential-only processing is not allowed by the system.
- If a file is being opened for output, it must be a physical file or a
logical file based on one physical file member.
- Sequential-only processing can be specified with commitment control only
if the member is opened for output-only.
- If sequential-only processing is being used for files opened with commitment
control and a rollback operation is performed for the job, the records that are
in the job's storage area during the rollback operation are not written to
the system storage area and never appear in the journal for the commitment
control transaction. If no records were ever written to the system storage
area prior to a rollback operation being performed for a particular commitment
control transaction, the entire commitment control transaction is not reflected
in the journal.
- For output-only, the number of records specified to be moved as a unit
and the force ratio are compared and automatically adjusted as necessary.
If the number of records is larger than the force ratio, the number of records
is reduced to equal the force ratio. If the opposite is true, the force ratio
is reduced to equal the number of records.
- If the program opened the member for output only, and if SEQONLY(*YES)
was specified (number of records was not specified), and duplicate or insert
key feedback has been requested, SEQONLY(*YES) will be changed to SEQONLY(*NO)
to provide the feedback on a record-by-record basis when the records are inserted
into the file.
- The number of records in a block will be changed to one if all of the
following conditions are true:
- The member was opened for output-only processing.
- No override operations are in effect that have specified sequential-only
processing.
- The file being opened is a file that cannot be extended because its increment
number of records was set to zero.
- The number of bytes available in the file is less than the number of bytes
that fit into a block of records.
The following considerations apply when sequential-only processing is not
specified and the file is opened using the Open Query File (OPNQRYF) command.
If these conditions are satisfied, a message is sent to indicate that sequential-only
processing will be performed and the query file is opened.
- If the OPNQRYF command specifies the name of one or more fields on the
group field (GRPFLD) parameter, or OPNQRYF requires group processing.
- If the OPNQRYF command specifies one or more fields, or *ALL on the UNIQUEKEY
parameter.
- If a view is used with the DISTINCT option on the SQL SELECT statement,
then SEQONLY(*YES) processing is automatically performed.