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4.2.8 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.


X For sequentially accessed relative files, the ACCESS MODE clause does not
X have to precede the RELATIVE KEY clause.

ACCESS MODE IS SEQUENTIAL
Can be specified in all four 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.


X Format 4--Line Sequential (Workstation Only)

X >_Workstation_> Records in the file are accessed in the sequence
X established when the file is created or extended. Format 4
X supports only sequential access. <_Workstation_<

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.

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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