Upgrading › Planning Your Upgrade › LREL Migration Considerations

LREL Migration Considerations

A List Relationship (LREL) represents an association between two objects. An LREL has a left-hand side (lhs) and right-hand side (rhs) relationship. Each side of the relationship is an attribute of the majic object that contains the data relationship.

In previous releases of the product, .maj LREL statements and objects described many-to-many DBMS data relationships. Many-to-many relationships no longer use the LREL majic statement. Instead, individual tables store both sides of the relationship. Objects access the relationship with a standard BREL statement. For example, you can see the relationship between change orders and CIs by reviewing the new usp_lrel_asset_chgnr table and in the corresponding lrel_asset_chgnr object.

The LREL changes eliminate the need to store attribute names in the database. The two sides of the relationship are foreign key single relationships (SREL) that are easy to join and index. If necessary, the relationship can contain additional relational attributes.

During the upgrade, the following activities occur as LREL table data migrates to Release 12.7:

• The system automatically migrates tables and objects with LREL relationships to Release 12.7 tables and objects.
• The system names new tables using the usp_lrel_lhsName_rhsName format.

  For example, the usp_lrel_asset_chgnr table has a left-hand relationship to assets and a right-hand relationship to change orders.

• The system names the corresponding objects using the lrel_lhsName_rhsName.

  For example, the lrel_asset_chgnr object corresponds to the usp_lrel_asset_chgnr table.

• Because of a database limitation, some names are abbreviated.
• Your data migrates from the old tables to the Release 12.7 tables, and all CA SDM code is modified to use these tables.
• The system no longer uses the old LREL database tables, such as bmlrel. However, for reference purposes, the old tables retain the data.
• A backward relation (BREL) attribute to the new object replaces the original LREL attribute in each related majic object definition.
• If you are using a supported API, such as the CreateLrelRelationship() web service method, the code works as expected.
• If you added any custom LREL style relationships, CA SDM migrates them to Release 12.7 tables.
• Any site-defined code or reports that directly access the old LREL tables operate on old data because the system no longer uses those tables. We recommend that you update the code to use the Release 12.7 tables so the code and reports run properly.

Important! If your code directly accesses legacy LREL objects or tables, the code fails after migration. We recommend that you upgrade the code before migration. For example, if your code uses majic statements to establish LREL relationships, use the createLrelRelationships() method instead of directly populating a table.

Note: We recommend that you verify site-defined code or reports that directly access the database or address the legacy LREL majic objects such as the lrel1 object to verify that they operate properly. You can update your code to use a supported interface, such as Web Services. You also update the necessary table names. For reports, you can also update the queries with the new DBMS table references.