NET/MASTER Network Control Language (NCL) Programmer's Guide

Enscribe File Structures and NCL
Working With Files
12–4 106160 Tandem Computers Incorporated
Entry-Sequenced Files
Entry-sequenced files are designed for sequential access. They consist of
variable-length records that are always appended to the end of the file in the order in
which they are presented. As a result, the records in the file are arranged physically
and logically in the order in which they are added to the file.
The primary key for records in entry-sequenced files is a record address maintained by
Enscribe. The record address is not part of the record.
NCL can read from and write to entry-sequenced files. Figure 12-2 shows the
structure of a record in an entry-sequenced Enscribe file. Figure 12-3 shows some
records in an entry-sequenced Enscribe file.
Figure 12-2. Record Structure in an Entry-Sequenced File
NAME ADDRESS PHONE AGE
Primary Key
026
<record address>
Figure 12-3. Records in an Entry-Sequenced File
613-4533LAKESIDE DRRIVER, O.M. 99
PHONEADDRESSNAME AGE
831-5043HILDA RDHUNT, L.Z. 45
453-8596JONES STADAMS, K.L. 12
777-2034EAST AVEWATSON, E.R. 45
414-5999SMITH STADAMS, J.P. 30
027
Key-Sequenced Files
Key-sequenced files consist of variable-length records that are accessed by the values
contained within designated key fields. There are two types of keys: primary
(required) and alternate (optional). The records in a key-sequenced file are stored
logically in ascending order, according to the value contained in their primary key
field.