Dimension Hieracrhy in Star Schema

Question

Hi devs,
I'm in the process of creating OLAP dimensions using AWM 10.2.0.30A on 10gR2 database, and have successfully created some flat (no levels) dimensions. Now I have to create another dimension, which based on existing model, has parent and child in same dimension table at database end.
When I first attempt to do this using the default "Star Schema" setting for type of dimension table in the mapping section, I get the below error:
oracle.AWXML.AWException: Action BUILDDATABASE failed on object TA_DMT_OWNER.GLA_MP
at oracle.AWAction.BuildDatabase.Execute(BuildDatabase.java:737)
at oracle.olap.awm.wizard.awbuild.BuildWizardHelper$1.construct(BuildWizardHelper.java:184)
at oracle.olap.awm.ui.SwingWorker$2.run(SwingWorker.java:109)
at java.lang.Thread.run(Thread.java:534)
Caused by: oracle.AWXML.AWException: ***Error Occured in BUILD_DRIVER: In __XML_SEQUENTIAL_LOADER: In __XML_LOAD_HIERS: In __XML_SET_GID_FREL: One or more loops have been detected in relationship GLA_MP!PROD_PARENTREL over GLA_MP!PROD. The 1 items involved are TD.
at oracle.AWAction.BuildDatabase.Execute(BuildDatabase.java:604)
... 3 more
I've tried changing the type to "Snowflake" but get the same error. Do you have suggestions as to how to best handle these scenarios?
**Little more background to the data. We DO have surrogate keys in table as well, which is used in fact table. If I do not use the "use natural keys from data source" and use "generate surrogate keys in AW" option, dimension is built successfully. So my follow-up question is, when I build cube will AW know to link the dimension correctly from fact based on surrogates generated by AWM even though those surrogate keys do not physically exist in fact?
Edited by: user8659932 on Oct 30, 2009 7:58 AM

Answer 1

When I first attempt to do this using the default "Star Schema" setting for type of dimension table in the mapping section, I get the below error:
oracle.AWXML.AWException: Action BUILDDATABASE failed on object TA_DMT_OWNER.GLA_MP
at oracle.AWAction.BuildDatabase.Execute(BuildDatabase.java:737)
at oracle.olap.awm.wizard.awbuild.BuildWizardHelper$1.construct(BuildWizardHelper.java:184)
at oracle.olap.awm.ui.SwingWorker$2.run(SwingWorker.java:109)
at java.lang.Thread.run(Thread.java:534)
Caused by: oracle.AWXML.AWException: ***Error Occured in BUILD_DRIVER: In __XML_SEQUENTIAL_LOADER: In __XML_LOAD_HIERS: In __XML_SET_GID_FREL: One or more loops have been detected in relationship GLA_MP!PROD_PARENTREL over GLA_MP!PROD. The 1 items involved are TD.
at oracle.AWAction.BuildDatabase.Execute(BuildDatabase.java:604)This error comes when you have a member rolloing to a different via two different path. If you use surrogate key then as you said the error is gone.
**Little more background to the data. We DO have surrogate keys in table as well, which is used in fact table. If I do not use the "use natural keys from data >source" and use "generate surrogate keys in AW" option, dimension is built successfully. It appended the some text to the value.
So my follow-up question is, when I build cube will AW know to link >the dimension correctly from fact based on surrogates generated by AWM even though >those surrogate keys do not physically exist in fact?Yes it do. You needn't to fabricate that kind of fact data.
You can check this link -> http://www.oracle.com/technology/products/bi/olap/index.html
Thanks,
Brijesh
Edited by: Brijesh Gaur on Oct 30, 2009 9:08 PM