1 Reply Latest reply on Jun 4, 2013 5:50 PM by SaichandVaranasi

    cardinality in BMM layer

    993000
    993000 Jun 4, 2013 4:57 PM
      Dear All ,

      I have a question in the rpd in OBIEE that is what difference we will get when we have given an option in the BMM layer as 1 to many 0r many to 1 to 1 in the Joining tables .I would like to know that this cardinality will give any difference in the record count in the reports .

      Please suggest me what is the usage of the cardinality in sql query out put .



      Thanks
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        • 1. Re: cardinality in BMM layer
          SaichandVaranasi
          SaichandVaranasi Jun 4, 2013 5:50 PM (in response to 993000)
          Hi,

          From the guide "A key property of a logical join is cardinality. Cardinality expresses how rows in one table are related to rows in the table to which it is joined. A one-to-many cardinality means that for every row in the first logical dimension table, there are 0, 1, or many rows in the second logical table. The Administration Tool considers a table to be a logical fact table if it is at the Many end of all logical joins that connect it to other logical tables"


          It really matters when you specify the driving tables if left hand side has less reocrds than right hand and makng it as driving table by menitoning the cardinality


          Thanks,
          Saichand
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