ACCESS MODE clause
The ACCESS MODE clause
defines the manner in which the records of the file are made available for
processing. If the ACCESS MODE clause is not specified, sequential access is
assumed.
For sequentially accessed relative files, the ACCESS MODE clause does not
have to precede the RELATIVE KEY clause.
- ACCESS MODE IS SEQUENTIAL
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Can
be specified in all formats.
- Format 1: sequential
- Records in the file are accessed in the sequence established when the
file is created or extended. Format 1 supports only sequential access.
- Format 2: indexed
- Records in the file are accessed in the sequence of ascending record
key values according to the collating sequence of the file.
- Format 3: relative
- Records in the file are accessed in the ascending sequence of relative
record numbers of existing records in the file.
- Format 4: line-sequential
- Records in the file are accessed in the sequence established when the
file is created or extended. Format 4 supports only sequential access.
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- ACCESS MODE IS RANDOM
-
Can
be specified in formats 2 and 3 only.
- Format 2: indexed
- The value placed in a record key data item specifies the record to be
accessed.
- Format 3: relative
- The value placed in a relative key data item specifies the record to
be accessed.
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- ACCESS MODE IS DYNAMIC
-
Can
be specified in formats 2 and 3 only.
- Format 2: indexed
- Records in the file can be accessed sequentially or randomly,
depending on the form of the specific input-output statement used.
- Format 3: relative
- Records in the file can be accessed sequentially or randomly,
depending on the form of the specific input-output request.
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