FTAM/9000 Programmer's Guide

Chapter 11 445
Document Types and Constraint Sets
Constraint Sets
Additional constraints on the Unstructured constraint set are as follows.
Sequential Flat Constraint Set
The Sequential Flat constraint set applies to files that are structured
into a sequence of individual FADUs. You can access specific FADUs in
the files by specifying their individual position in the sequence. Refer to
the following list for applicable basic constraints.
Structural Constraints All actions in the unstructured constraint set result in a
structure with a root node that has a data unit (although this
data unit may be empty).
Action Constraints The FT_FA_ERASE action yields a root node with an empty
data unit.
Identity Constraints The FADU identity is always FT_FIRST. Use this form of FADU
identity with all permitted file actions.
Constraint Set Name Sequential Flat
Constraint Set Identifier ISO Standard 8571 constraint-set (4) sequential-flat (2)
(ASN.1 syntax for an identifier)
Node Names None
File Access Actions FT_FA_ERASE
FT_FA_LOCATE
FT_FA_INSERT
FT_FA_READ
Qualified Actions None
Available Access Contexts FT_FLAT_ALL_DATA_UNITS (FA)
FT_UNSTRUCTURED_ALL_DATA_UNITS (UA)
Creation State Root node without an associated data unit
Location After Open Root node
Beginning of File Root node