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Does BI 7.0 use bit map join indexes?

Former Member
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I have seen several threads on SDN which show that SAP BI is using bit map indexes with Oracle database. However, it is not clear whether BI utilizes bit map join indexes or just bit map index. Bit map index is on a single table whereas bitmap join index is on a join of two or more tables.

It will make sense for SAP BI to use bit map join indexes with star transformations where a join is done among fact and dimension tables.

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lbreddemann
Active Contributor
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Hi there,

you're right, SAP BI on Oracle makes heavy use of bitmap indexes.

These are especially important for queries that benefit from a special data access technique called "star transformation".

The join indexes are not used (yet) with SAP BI, but since there are Oracle guys sitting together with the SAP BI development you can be absolutely sure that each and every piece of technology is in fact considered.

So, if you're missing a specific feature usage don't think that the BI development did not knew about it.

In reality most of the fancy features turn out to have limitations that make them not so interesting for SAP BI.

Thomas Zurek, one of the BI development heads has written some blog entries that might be interesting for you: [https://www.sdn.sap.com/irj/scn/weblogs?blog=/pub/u/8448] [original link is broken] [original link is broken];

Look for the "NetWeaver BI (a.k.a. BW) and Advanced DB Functionality" issues.

regards,

Lars

Former Member
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Thanks. Another question, are bit map indexes used both for F and E fact tables or just for F. I am not using real-time cubes (where SAP BI uses B-Tree indexes for F table to avoid dead locks).

lbreddemann
Active Contributor
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> Thanks. Another question, are bit map indexes used both for F and E fact tables or just for F. I am not using real-time cubes (where SAP BI uses B-Tree indexes for F table to avoid dead locks).

Why don't you simply check this in your BI system yourself?

And, yes, of course it uses bitmap indexes for both fact table types.

E-fact tables are the same as F-Facttables except that they contain the compressed/rolled up data.

regards,

Lars