The text read off it
[02.07.05]
a record which is in a buffer area. In the 709/7090 system, records may be either located or transmitted. Transmission occurs when either the HOLD or SPANS option is specified for the file in the Environment Description, SPANS being designated when records in the file may span blocks and HOLD when records of different names must be available from a file at the same time.
b) Relative Efficiency
The locate mode allows for more efficient utilization of memory, as no additional space outside of the buffer area is required for record storage.
The locate mode allows for more efficient processing of records whose fields are referenced only infrequently in arithmetic, MOVE, or indexing operations. In general, a record should be transmitted if the number of words in the record is less than three times the total number of arithmetic and MOVE references to fields of the record.
c) Miscellaneous Requirements of Locate and Transmit Modes
i. If the locate mode is being used, no references can be made to the record or its fields until after execution of a GET command for that record. All references to fields of a located record initially specify location zero. Upon a GET these references are adjusted to reflect the location of the data within the buffer area. If references are made to located fields prior to the first automatic GET adjustment the low order portions of memory (the monitor) will be irreparably damaged.
ii. When through use of the type code REDEF a record is specified to share an area with data other than records within the same file, all records of the file are automatically 'transmitted'. If the records of the file were originally to be located a message is printed indicating this change.
iii. All records of a file (whether located or transmitted) which are related through use of the Data Description type code REDEF are made available for processing when any one of the records is requested with the GET command. When records of a file processed in the locate mode are obtained using the GET RECORD FROM file.name form of the verb the result is as described above.
2. End of File Processing
The AT END clause which may be used with the GET command may consist of a single imperative statement only. The clause is used to specify the action