The SAS Metadata Model
defines approximately 170 metadata types that represent application
elements. The metadata types are intended to be used in combination
by clients to create metadata describing application data or entities
used by an application.
The metadata programmer
begins by selecting a metadata type that most closely describes the
entity for which he wants to store metadata. For example, when creating
metadata describing a data source, a metadata programmer might select
the PhysicalTable metadata type to represent data in a table. This
becomes the primary or top-level object in the metadata definition.
He then needs to examine the SAS Metadata Model to select metadata
types that provide supporting information. For example, to describe
each table's columns, he might use the Column metadata type. If the
tables have passwords, he might use the SASPassword metadata type,
and so on. These are considered secondary objects in the metadata
definition.
Once he has identified
all of the metadata types necessary to fully describe the data source,
he can use the AddMetadata method to create metadata objects representing
each metadata type, and to associate the objects with one another.
To assist metadata programmers
in building consistent metadata definitions, the SAS Metadata Model
categorizes metadata types as being either primary or secondary:
-
Metadata types that are subtypes
of the PrimaryType supertype are intended to be used as the topmost
object in a metadata definition, or to describe an application element
that provides supporting information, but can be referenced, secured,
and deleted independently of the primary object that it supports.
-
Metadata types that are subtypes
of the SecondaryType supertype provide supporting information for
a primary type and are never referenced directly within a SAS application.
For a list of the metadata
types in each category, see the descriptions of the PrimaryType and
SecondaryType metadata types in the
SAS Metadata Model:
Reference.
The PrimaryType metadata
type defines attributes and associations that support the management
of the entities described by the metadata definitions. For more
information about these attributes and associations and how they should
be used, see "PrimaryType and SecondaryType Abstract Types" in the
model reference.
SAS uses a type dictionary
to manage the logical metadata definitions that are used to represent
object types that are common to or shared by SAS Intelligence Platform
applications. To determine the primary metadata types used to represent
common and shared object types, view the type dictionary. The dictionary
is in the /System/Types folder of the SAS Folders tree.