<vdb name="{vdb-name}" version="1">
<model name="{model-name}" type="PHYSICAL">
<source name="AccountsDB" translator-name="oracle" connection-jndi-name="java:/oracleDS"/>
<metadata type="NATIVE"></metadata>
</model>
</vdb>Metadata Repositories
Traditionally the metadata for a Virtual Database is supplied to Teiid engine through a VDB archive file. A number of MetadataRepository instances contribute to the loading of the metadata. Built-in metadata repositories include the following:
NATIVE
This is only applicable on source models (and is also the default), when used the metadata for the model is retrieved from the source database itself.
Sample vdb.xml file
DDL
Sample vdb.xml file
<vdb name="{vdb-name}" version="1">
<model name="{model-name}" type="PHYSICAL">
<source name="AccountsDB" translator-name="oracle" connection-jndi-name="java:/oracleDS"/>
<metadata type="DDL">
**DDL Here**
</metadata>
</model>
</vdb>This is applicable to both source and view models. See DDL Metadata for more information on how to use this feature.
DDL-FILE
Sample vdb.xml file
<vdb name="{vdb-name}" version="1">
<model name="{model-name}" type="PHYSICAL">
<source name="AccountsDB" translator-name="oracle" connection-jndi-name="java:/oracleDS"/>
<metadata type="DDL-FILE">/accounts.ddl</metadata>
</model>
</vdb>DDL is applicable to both source and view models in zip VDB deployments. See DDL Metadata for more information on how to use this feature.
UDF (11.2+)
Sample vdb.xml file
<vdb name="{vdb-name}" version="1">
<model name="{model-name}" type="VIRTUAL">
<property name="importer.schemaName" value="org.foo.Class"/>
<metadata type="UDF"></metadata>
</model>
</vdb>Sample ddl file
CREATE DATABASE {vdb-name} VERSION '1';
USE DATABASE {vdb-name} VERSION '1';
CREATE VIRTUAL SCHEMA {model-name};
IMPORT FOREIGN SCHEMA "org.foo.Class" FROM REPOSITORY UDF INTO {model-name};The logic will import all static functions that return non-void results, or import the user defined aggregate function if the class implements the UserDefinedAggregate interface.
Chaining Repositories
When defining the metadata type for a model, multiple metadata elements can be used. All the repository instances defined are consulted in the order configured to gather the metadata for the given model. For example:
Sample vdb.xml file
<vdb name="{vdb-name}" version="1">
<model name="{model-name}" type="PHYSICAL">
<source name="AccountsDB" translator-name="oracle" connection-jndi-name="java:/oracleDS"/>
<metadata type="NATIVE"/>
<metadata type="DDL">
**DDL Here**
</metadata>
</model>
</vdb>|
Note
|
For the above model, NATIVE importer is first used, then DDL importer used to add additional metadata to NATIVE imported metadata. |