Documenting Record Layout; Determining The Number Of Records In A File - IBM 5110 User Manual

Documenting Record Layout
When record layouts are documented, your APL user-defined function
might be easier to write. A record layout should include the order of
the fields in the record, the length of each field, and the name of each
field. The following illustration shows the layout of a customer master
record:
Customer
Number
Street Address City and State Other Fields Reserved Space
Delete
Code
89 2829
4849 6869 127 128
In the previous example, the sum of the fields is 116 positions.
However, the record size is 128 positions, thus reserving 12 positions
for data that might be needed at a later time.
Determining the Number of Records in a File
When determining the number of records in a file, you should consider
expansion for a reasonable time into the future (at least six months).
Then when you create the file, if you place dummy records in the file,
these dummy records· can then be replaced with valid records at a
later time. Of course, you can also add records to the file using an
ADD operation.
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