COBOL Manual for TNS/E Programs (H06.08+, J06.03+)

define-name-literal
is a nonnumeric literal that represents the name of a DEFINE of class MAP that is associated
with a disk file. Quotation marks must enclose any DEFINE name. For information about
DEFINE names, see DEFINEs (page 593).
RESERVE clause
enables or prevents sequential block buffering on input and buffered cache on output, or
enables or prevents HP COBOL Fast I-O for both input and output, for a disk file, depending
on the value of number.
number
is a numeric literal, an unsigned integer.
number must be in the range 1 through 32, and its value is interpreted:
EffectValue of number
No buffering or HP COBOL Fast I-O1
Sequential block buffering on input and buffered cache on output if the
assigned file qualifies
2
HP COBOL Fast I-O if the assigned file qualifies; if not, sequential block
buffering for input and buffered cache for output if the assigned file qualifies;
otherwise normal I-O.
3 or greater
number is the number of blocks to buffer.
CAUTION: Do not use sequential block buffering for a file opened for shared access. If you do,
a process could read outdated data while another process alters the file. For information on shared
access, see OPEN (page 375).
ORGANIZATION clause
makes the organization of the file indexed (the default is sequential).
ACCESS MODE clause
SEQUENTIAL
makes the access mode of the file sequential (the default). That means the records of the
file are to be operated upon as if they were sequentially organized.
RANDOM
makes the access mode of the file random. That means the records of the file are to be
operated upon in any order, as selected by the current value of the record key or of an
alternate key. The default access mode is sequential.
Input-Output Section 133