Data Definition Language (DDL) Reference Manual

Data Definition Language (DDL) Reference Manual—529431-004
5-1
5 Definitions and Records
Definitions and records are dictionary objects that describe data structures and disk-file
record structures, respectively.
DEFINITION and RECORD statements:
•
Define definitions and records, respectively
•
Must conform to the syntax rules in Statements on page 2-16
•
Have many syntax elements in common
•
Are usually specified in a schema file that is used as the IN file when the DDL
compiler is executed noninteractively
Topics:
•
DEFINITION on page 5-1
•
RECORD on page 5-8
•
Syntax Elements on page 5-21
DEFINITION
The DEFINITION statement defines an elementary or group data structure by
specifying its name, data type, size, and other attributes.
The definition can be added to the open dictionary; referenced for defining other data
structures, record structures, token types, or token maps; and compiled into a DDL or
host-language source code file.
If a DEFINITION statement names a definition that is already in the open dictionary
and no other object refers to the definition, the DDL compiler replaces the existing
definition with the new definition. If another object refers to the existing definition, the
DDL compiler issues an error message and does not add the new definition to the
dictionary.
If a previous command opened any language source code files, the DDL compiler
translates the definition to the specified language and writes it to the open source code
files.
Note. For the DDL2 object file, if a definition is used only for the working storage, the length of
the definition or any of its fields is limited to 2,097,152 bytes. This length is limited to 32,767
bytes in the DDL object file.
Caution. The DDL and DDL2 object files are not compatible with each other. The DDL2 object
file cannot read or write to the dictionary created using the DDL object file. Similarly, the DDL
object file cannot read or write to the dictionary created using the DDL2 object file. Therefore,
you must generate the schema from the existing dictionary before deleting the dictionary.