Exporting the Server Metadata¶
There are four options to export the metadata from the Server:
In the Elements Tree, right-click on the element you want to export and click on Export. This option exports the metadata of the selected element.
Export database (File > Export database menu): exports the contents of one or more Denodo virtual databases. For each database, the output includes the metadata of data sources, views, Web services (including the statements to deploy them if they were deployed), JMS listeners, etc.
Export (File > Export… menu): exports all the contents of the Virtual DataPort Server (see Export dialog). That includes:
- The metadata from all the databases of the Server. Not just the database that you are currently connected to.
- Users, roles and their privileges.
- Server settings.
This option is available only for administrator users.
Use the export script included in the Denodo Tools toolkit. The section Using the Import/Export Scripts for Backup And/or Replication explains how to use this script.
After exporting the metadata of a Virtual DataPort server, it can be imported back to the same Server or into another one. The section Exporting and Importing Elements Across Different Environments explains how to do this.
The Export and Export database dialogs of the File menu have the following options:
Output file: file where the VQL statements to recreate the metadata will be stored.
Export environment specific properties separately. If selected, the metadata is stored in two files:
- A file with the name Output file that contains the VQL statements of all the elements of the database. The values of the parameters that depend on the environment are variables instead of the actual values.
- And, a file that contains the values of the variables. The name of
this file is the same as Output file but with the extension
.properties. This option makes exporting and importing metadata across different environments, easier. See more about this in the section Exporting and Importing Elements Across Different Environments.
In the “Export database” dialog, if you select the option Database, you can select the databases whose metadata you want to export. In this case, you can select all the databases but take into account that doing this is different than exporting the metadata from the “Export” dialog. That is because, in addition to the metadata of the databases, the output of the “Export” dialog also includes the settings of the Virtual DataPort server.
If you select Web service, you can select Export specific web service operations and then, select which operations (if you selected a SOAP web service) or resources (if you selected a REST web service) you want to export. The output file will have the VQL statement an ALTER WEBSERVICE, which does not create the web service but adds the selected operations to an existing web service.
For example, if you have a web service called “incident” that publishes the view “incident” and you just export this resource, the output file will be like this:
ALTER REST WEBSERVICE incident SET VIEW incident FIELDS ( summary : 'text', ttime : 'date', taxid : 'text', inc_type : 'long' );
Replace / Drop elements. Select the action that a Virtual DataPort server will take when importing this VQL file and the server has elements (data sources, views, etc.) with the same name and type as the ones that is importing:
Drop elements before creating them. Before creating a new element, it will delete, if exists, the element with that name and all the elements that depend on it.
E.g. when a server imports a JDBC data source
ds_jdbc_acme, first it will delete the existing JDBC data source
ds_jdbc_acmeand all the views that depend on this data source.
This option is useful when you want to make sure that the imported data sources do not have more views that the ones contained in the VQL file.
Replace existing elements. It will replace the existing elements with the elements from the file.
E.g. when importing a LDAP data source
ds_ldap_activedirectoryand the Server already has a LDAP data source with that name, the server will replace this data source with the one from the VQL file. However, it will not modify or delete the views that depend on the existing data source.
Do not replace existing elements. It will keep the existing elements and ignore the ones from the file.
E.g. if the server has a view
internet_incand the VQL file contains a view with that name, the server will keep the existing view, instead of deleting it or replacing it.
This option is useful when we need to add more elements to the server without affecting the existing ones.
Export dependencies (only for “Export database” and when the selected element is not Database). If selected, and the selected type is:
View, the output will include all the necessary elements to create this view (other views, types, data sources, folders, etc.)
Folder, the output will include the statement to create the folder and its inner elements. It will also include the statements to create the elements that the elements of the folder rely on.
Web service, the output will include the statements to create the Web service and the elements that this Web service relies on: views, data sources…
The output will not include the metadata of the elements published by the Web service if you have added them to the Web service with the Publish from VQL expression dialog.
Widget, the output will include the statements to create the widget and the elements that this widget relies on.
Stored Procedure, output will include the statement to create the folder(s) where the stored procedure is stored in.
Create Virtual Database (only for the “Export database” dialog). If selected, the output will include a
CREATE DATABASEstatement so, when the metadata is imported, the database will be recreated and all the metadata will be created in this database. If it is not selected, when the metadata is imported, the elements will be created in the database that you are connected at that moment.
Include Jars. If selected, the output will include the Jars that contain the Java classes used to create:
- Stored procedures.
- Custom data sources (also known as Custom Wrappers)
- Virtual DataPort custom functions.
- ITPilot custom functions.
These classes belong to the Jar files that were imported into the Server with the Jar management dialog (see section Importing Extensions).
Include ITPilot custom components. If selected, the output will include the ITPilot custom components used by the WWW data sources.
Enter Single Mode during Import. If selected, the file generated will begin with the statement
ENTER SINGLE USER MODEand finish with
EXIT SINGLE USER MODE, so that Virtual DataPort switches to single user mode while importing this file (see section Importing Metadata of the VQL Guide).
You are strongly advised to import metadata in a Virtual DataPort server in single user mode.
Include users and privileges. If selected, the output will include the statements to replicate the privileges of the exported elements. That is, it will include the statements to do the following:
- Create the users and the roles that are owners or have privileges assigned over the exported elements.
- Assign the privileges to these users/roles over the exported views.
This option is only available in “Export database” and not in the “Export” dialog because when exporting the metadata of the entire Server, you already are exporting all this information.
Include view statistics. If selected, the output will include the statistics gathered for the views that are used by the cost-based optimization.