Red Hat Summit Red Hat SummitSupportKonsoleEntwicklerDemo startenKontakt

Dieser Inhalt ist in der von Ihnen ausgewählten Sprache nicht verfügbar.

Chapter 10. Migrating legacy virtual database files to DDL format

The data virtualization Technology Preview requires that you define the structure of virtual databases in SQL-MED DDL (data definition language) format. By contrast, the structure of legacy Teiid virtual databases, such as those that run on Wildfly, or on the Red Hat JBoss Data Virtualization offering, are defined by using files that are in .xml or .vdb format.

You can reuse the virtual database designs that you developed for a legacy deployment, but you must first update the format of the files. A migration tool is available to convert your files. After your convert the files you can rebuild the virtual databases as container images and deploy them to OpenShift.

Migration considerations

The following features that were supported in virtual databases in JBoss Data Virtualization and Teiid might be limited or unavailable in this Technology Preview release of data virtualization:

Data source compatibility
You cannot use all data sources with this release. For a list of compatible data sources, see Section 2.1, “Compatible data sources”.
Internal distributed materialization
Not available.
Resultset caching
Not available.
Use of runtime metadata to import other virtual databases
DDL must be used to specify metadata for virtual databases.
Runtime manipulation of multisource vdb sources
Not available.

You can use the migration utility in the following two ways:

To validate a VDB file only
Use this method to check whether the utility can a successfully convert a VDB file. The utility converts the VDB file and reports validation errors to the terminal. If there are no validation errors, the utility displays the resulting DDL, but it does not save the converted DDL to a file.
To validate and a VDB file and save it to a DDL file
The file is saved only if there are no validation errors.

The migration tool works on XML files only. Files with a .vdb file extension are file archives that contain multiple folders. If you have legacy files in .vdb format, use Teiid Designer to export the files to XML format, and then run the migration tool to convert the resulting XML files.

Prerequisites

  • You have a legacy virtual database file in .xml format.
  • You download the settings.xml file from the Teiid OpenShift repository. Maven uses the information in the file to run the migration tool.

You can run a test conversion on a legacy virtual database to check for validation errors and view the resulting DDL file. When you run the migration tool in this way, the converted DDL file is not saved.

Procedure

  1. Open the directory that contains the settings.xml file that you downloaded from the Teiid OpenShift repository, and type the following command: 

    $ mvn -s settings.xml exec:java -Dvdb=<path_to_vdb_xml_file>
    Copy to Clipboard Toggle word wrap

    For example: 

    $ mvn -s settings.xml exec:java -Dvdb=rdbms-example/src/main/resources/vdb.xml
    Copy to Clipboard Toggle word wrap

    The migration tool checks the specified .xml file, and reports any validation errors. If there are no validation errors, the migration tool displays a .ddl version of the virtual database on the screen.

You can run the migration tool to convert a legacy virtual database file to .ddl format, and then save the .ddl file to a specified directory. The migration tool checks the .xml file that you provide for validation errors. If there are no validation errors, the migration tool converts the file to .ddl format and saves it to the file name and directory that you specify.

Procedure

  • Open the directory that contains the settings.xml file that you downloaded from the Teiid OpenShift repository, and type the following command: 

    $ mvn -s settings.xml exec:java -Dvdb=<path_to_vdb_xml_file> -Doutput=<path_to_save_ddl_file>
    Copy to Clipboard Toggle word wrap

    For example: 

    $ mvn -s settings.xml exec:java -Dvdb=rdbms-example/src/main/resources/vdb.xml -Doutput=rdbms-example/src/main/resources/vdb.ddl
    Copy to Clipboard Toggle word wrap
Nach oben
Red Hat logoGithubredditYoutubeTwitter

Lernen

Testen, kaufen und verkaufen

Communitys

Über Red Hat Dokumentation

Wir helfen Red Hat Benutzern, mit unseren Produkten und Diensten innovativ zu sein und ihre Ziele zu erreichen – mit Inhalten, denen sie vertrauen können. Entdecken Sie unsere neuesten Updates.

Mehr Inklusion in Open Source

Red Hat hat sich verpflichtet, problematische Sprache in unserem Code, unserer Dokumentation und unseren Web-Eigenschaften zu ersetzen. Weitere Einzelheiten finden Sie in Red Hat Blog.

Über Red Hat

Wir liefern gehärtete Lösungen, die es Unternehmen leichter machen, plattform- und umgebungsübergreifend zu arbeiten, vom zentralen Rechenzentrum bis zum Netzwerkrand.

Theme

© 2025 Red Hat