Background
The
contents of XMETA Metadata repository for InfoSphere Information
Server 9.1 and prior releases is not directly accessible to any
external application. This is due to the fact that it is designed
using the EMF model. These models are often very abstract and
generic, which makes them difficult to be understood by an
application – especially if the application is not familiar with
the semantics of the model. Further, the database tables and views of the metadata
repository are not uniform across the different database platforms
supported by Information Server. The problem is further compounded by
the fact that database table and views names are very cryptic and not
uniform across databases. Proper relationships are also not defined
between database tables. The solution for this problem is SQL views.
What are SQL
Views
SQL Views
are set of predefined / custom database views defined on top of the
XMETA metadata repository thus allowing users to access subset of
XMETA metadata repository in read only mode. These views not only
hide the internal information (eg: XMETA stores Dates as long values
whereas views retrieves them as Dates field) and it's complexities of
XMETA repository, it also provides uniform access across different
database platform. SQL Views are grouped into separate schemas (aka
View Schema) based on product/model area. These views can be directly
accessed by any external or internal application using ODBC/JDBC. A
dedicated Model Schema is also available for each of the View schema
with tables derived from the views having same names and structure.
These model schema can be used for development purpose. Primary and
foreign keys that represents the original model references and
inheritance relationships are defined on the tables. These model
tables and associated keys can be imported to generate the reporting
model from which different reports can be designed.
Why to use
SQL Views
SQL Views
makes XMETA metadata repository accessible through internal and
external applications via JDBC/ODBC. SQL Views decouple applications
from the underlying persistent model and minimize the impact of model
upgrades and development locksteps. It also provides the work around
from some of the internal proprietary XMQL limitation (eg: support
for scalar functions). These views are uniform across database
platforms and are easily consumable. Persistent data representations
are converted to more friendly types in the views when applicable
(eg: Long integers to SQL timestamps). All the internal system
attributes (eg: lockids, blobs holding objects) are filtered out of
the views. By creating SQL Views in separate and dedicated schema,
the security is enforced at the database level whose access can be
restricted. SQL views also gives the ability to filtered out in the
view definitions
Where to use
them:
SQL Views
makes it possible to integrate any application which needs to access
XMETA's metadata using JDBC/ODBC. It also can be used to integrate
with any reporting tool like IBM Cognos. Starting InfoSphere
Information Server 11.3, suite bundle comes with predefined set of
sample Cognos report which can be directly used in IBM Cognos
environment with minimal or no changes.
Available
SQL Views with InfoSphere Information Server 11.3
Starting
with InfoSphere Information Server 11.3, SQL Views are available in 3
different functional/domain areas. These functional areas are Common
Metadata, Data Quality and Information Governance.
- Common
Metadata Views
Common
Metadata contains SQL Views for subset of Common Model object types
that represent database metadata that in usually imported by bridges
or connector. These SQL Views describe hosts, databases, schemas,
tables, views, stored procedures,and columns. In addition there are
views for notes (annotations), users, and stewardship assignments.
- Data
Quality Views
Data Quality contains SQL Views for object types from the data
quality domain that are created in InfoSphere Information Analyzer:
projects, data rules, data rule sets, data rule definitions, data
rule set definitions.
- Information
Governance Views
It
contains SQL Views for object types from the Information Governance
domain that are created in InfoSphere Information Governance Catalog,
including categories,terms, labels, information governance policies,
and information governance rules. This also includes SQL Views that
link information governance objects to the data rules that implement
them, and to other common metadata assets.
Disclaimer:
“The postings on this site are my own and don’t necessarily
represent IBM’s positions, strategies or opinions.”
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