SAP PowerDesigner LDM bridge reference

About this bridge

The SAP PowerDesigner LDM bridge imports logical data models in LDM XML files that are created by PowerDesigner versions 15 and 16. LDM files in binary format are not supported.

Prerequisites

To use the latest version of the bridge, you must install the prerequisite software.

You must create an LDM file to import. Transfer the import file to the local computer or the metadata interchange server that you are using for the import.

To create an LDM file for import, open a logical data model in PowerDesigner and save it as Logical Data Model (xml) (*.ldm).

Frequently asked questions

How do I handle LDM files that contain shortcuts to external entities?

LDM XML model files can contain relationships that refer to entities that are defined as shortcuts, which are references to external entities. However, the LDM XML file does not contain sufficient information for the bridge to reconstruct the primary key and foreign key relationships. If a file that you import contains such references, the import log file contains a message such as: This model might have shortcut dependencies on an external model: '[model_name]'.. The bridge does not reconstruct the relationships to shortcuts.

You can merge the models in PowerDesigner to resolve the shortcuts:

1. Check the import log file to compile a list of all the model files that are referenced by short cuts in the current model.
2. In PowerDesigner, click Tools > Merge Models, and merge the model and its referenced models into a new model.
3. Save the new model as LDM XML and reimport the file.

I see warnings or errors in the log. How can I validate the model before importing?

In PowerDesigner, select Tools > Check Model. Resolve any issues that you detect.

Import parameters

The SAP owerDesigner LDM 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 LDM file to import.

Remove invalid binary characters

Specify whether to filter invalid binary characters from the file before the LDM XML file is parsed.

This option is a workaround for a bug in PowerDesigner, which sometimes generates a file with binary characters that does not conform to the XML specification.

The filter might remove some Unicode national characters. If the filter removes Unicode national characters, remove the check mark from the selection.

The default behavior is to remove invalid binary characters.

Import UDPs

A UDP (user-defined property) is usually defined with a property definition object that has a default value. The objects that the property applies to might also specify an explicit value or no value at all for this property, 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.

Append volumetric information

Select whether to import volumetric information (the number of occurrences) and append it to the description property. By default, the volumetric information is not imported.

Remove text formatting

Select this option. InfoSphere Information Server does not support the display of RTF text in descriptions.

Reverse role names

Select this option if you want the bridge to swap (reverse) the role names for each relationship in the model. By default, the role names are not reversed.

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 cannot validate the metadata.

No check

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

If an asset description already exists

Specify what action to take if an imported asset matches an existing asset in the metadata repository. You can keep the existing description, or overwrite the existing description with the description of the imported asset.

If either description is null, the non-null description is used, regardless of which option you specify. The default behavior is to replace the existing description.