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Summary

REP010 - Access Routes and PJFs

Important Observations

• Your file OAM needs to be recompiled once access routes are added.

• The type of PJF that can be created is based on the definition of the access route. If the relationship is one to one, only a lookup can be created. If the relationship is one to many, calculation type PJFs can be added.

• PJFs are listed in the Field in File tab and can be edited from this tab but they cannot be added. You need to add a PJF by first selecting an access route on which the PJF will be based.

• In addition to defining PJFs, access routes are used in LANSA templates to show related files and in LANSA Client to show linked or joined files.

Tips and Techniques

• The Keep last parameter is used to improve performance. It specifies the number of retrieved PJF values to be kept in memory.  This value applies to PJFs defined on the access route when the relationship is one to one.

• Be very careful with excessive use of PJFs. There are performance implications of overusing PJFs.

• You can also use trigger functions to perform the same type of calculations or lookup operations that are performed by a PJF.

What I Should Know

• What an access route is.

• How an access route is defined.

• Where access routes are used.

• Where else in LANSA access routes are used.

• What a Predetermined Join Field is.

• What operations can be performed by a PJF.

• How to add and maintain PJF definitions.

• What the relationship between PJF and access routes is.

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