CA ERwin 4 Data Modeler bridge reference

About this bridge

The CA ERwin 4 Data Modeler bridge imports logical data models and physical data models from files that are produced by CA AllFusion ERwin Data Modeler 4.

This bridge imports files in either ER1 or XML format. The bridge parses the XML files natively, but requires the CA AllFusion ERwin Data Modeler COM/OLE API to parse ER1 files.

When you import a physical data model, you have the option on the Identity Parameters screen to create a database schema that implements the physical data model. Both the schema and the physical data model are stored in the metadata repository.

Prerequisites

To import ER1 files, you must install CA AllFusion ERwin Data Modeler 4 on the same computer that the bridge is installed on. You must be able to open the ER1 file with the installed version of ERwin.

To import XML files, ensure that CA AllFusion ERwin Data Modeler was installed with the option to save XML files in the Advantage Repository format. This option is not installed by default. If necessary, modify the installation to install the option. To create an XML file for import, open the ER1 file in ERwin 4 and save it as XML in the Advantage Repository format

Frequently asked questions

Which ERwin version does this bridge support?

The bridge supports the 4002 XML file version generated by ERwin 4.0 (SP1) build 1511 and later versions. The bridge does not support the XML format produced in earlier versions of ERwin 4.0 such as ERwin 4.0 Patch 1 (build 1338).

How does the bridge import the order of entity attributes?

The bridge imports the physical column order if the information is present in the XML file. Otherwise, the bridge maintains the order of entity attributes.

The order of attributes might not be the same after you use the bridge to import the file. To view the order of attributes in CA Erwin 4 take the following steps:

• Switch to the model Physical View.
• From the Format menu, select Stored Display Settings.
• On the Physical tab, and select Physical Order.

Why do I see the message Error getting persistence units when I run the bridge with an ER1 file?

This message usually indicates that ERwin requires more information to translate between the ER1 and XML formats. You can usually resolve this error by opening the ER1 file in the latest version of ERwin 4 and saving it again as XML.

Troubleshooting

Missing physical names in XML files

When you save a logical and physical model, the physical names of tables, columns, and keys might not always be saved into the XML file. When you use ERwin to manage the automatic generation of physical names from logical names, only the generation rules are saved. Missing physical names are not an issue for physical-only ERwin models or when you import ER1 files.

There are several ways to work around this issue:

• Use the Advantage Repository Export feature in the ERwin 4 add-in for the Advantage Repository. This add-in is available in versions starting with ERwin V4.1 SP1 (build 2522). You install it by using the ERwin 4 installer wizard. The add-in generates an XML file in which the physical names are explicitly expanded. Import the generated XML file by using this bridge.
• Explicitly set all physical names so that you do not rely on generation rules to create them from the logical names.
• Derive a new physical model from your existing logical and physical model. Use the Derive New Model option on the Tools menu in ERwin 4. The generation rules are invoked to produce all the physical names. You can then save the new physical model as XML. The logical names of tables are also available in this new XML file, but the logical names of attributes might still be missing.

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Missing discriminator of subtype relationships

Discriminators of subtype relationships might be missing when you import an ERwin 3.5 ER1 file into ERwin 4.0 (SP1) build 1511 and save it as XML. Open the subtype relationship window and reselect the discriminators before you export the XML.

Import parameters

The CA ERwin 4 Data Modeler bridge uses the following import configuration parameters.

File location

Select whether the file that you specify for the File parameter is on the metadata interchange server or on the local computer.

File

Required. Specify the name and path of the XML or ER1 file to import. To import ER1 files, you must install CA AllFusion ERwin 4 Data Modeler on the same computer that the bridge is installed on.

Filter binary characters

This parameter applies to XML imports. You can filter out invalid binary characters in the XML file before the import runs.

This is a workaround for a bug in the ERwin 4 software that sometimes generates a file that contains binary characters and does not conform to the XML specification. If the filtering process removes any Unicode national characters, run the import again with the selection cleared. The default is to filter out invalid binary characters.

Import IDs

The bridge ignores this option regardless of which selection you make. InfoSphere® Information Server does not support importing native IDs.

Import user-defined properties (UDPs)

A UDP is usually defined with a property definition object that has a default value. Objects that the property applies to might also specify an explicit value for this property, or no value at all, in which case the default value of the property definition applies. InfoSphere Information Server supports importing UDPs only by appending the property name and value to the description property of the object. To append the property name and value, even if implicit, to the description property of an object, select In description, migrate default values. If you select any other value for this parameter, the UDP information is not imported.

Import relationship names

Regardless of which value you select, InfoSphere Information Server handles the import of relationship names in the following way:

• For imports from logical/physical models, relationship names are imported from the name property.
• For imports from physical models, relationship names are imported from the constraint name of the foreign key.

To use relationship names in InfoSphere DataStage® and QualityStage® jobs, ensure that the names do not contain spaces.

Import subject areas

Specify how to handle ERwin subject areas.

If you choose to import subject areas, you can import them either as diagrams or as packages and diagrams.

Import parent schemas

Specifies if parent schemas for tables and views are imported. Accept the default value, True. InfoSphere Information Server relies on the identity of the parent schemas to create the identity of tables and other assets.

Metadata consistency check

Perform a consistency check on the selected metadata before it is imported into the metadata repository. It is possible to save metadata in source tools in ways that cause problems when the assets are imported into the metadata repository or used in other tools. For example, a foreign key might have no connection to a primary key or to an alternate key. In some cases, the metadata might be so semantically inconsistent that the bridge cannot import it.

The metadata consistency check returns warnings and errors in the log file.

Basic check

The default. Performs the minimum consistency checks necessary to validate the metadata, including checking for missing relationships and foreign keys that are not connected to primary or alternate keys.

In some cases, the basic check might be more rigorous than necessary and you can ignore certain errors or warnings.

Detailed check

Performs the basic check plus more advanced semantic checks specific to the type of metadata that is imported. This level can be used when the source tool does not have the ability to validate the metadata.

No check

Use with extreme caution. Selecting this option could result in the import of duplicates or invalid identities and might cause serious problems with your use of suite tools and the metadata repository.

Qualify table names

For imports of physical data models, select this option to add the owner name to the table name, in the form owner_name.table_name. The owner name is added only for those tables where an owner name is specified in the source file.

Select this option if the design tool allows you to create tables with the same name in the same model. Otherwise, the tables with the same name are created as duplicate design tables when they are imported into the metadata repository.