Join Elimination: Difference in Oracle 11g and 12c

Join elimination is a query transformation of the Oracle optimizer to remove joins that are not required in a query. A very practical features for star schema queries as well as ETL processes in data warehouses, but it is important to know what preconditions must be satisfied. And good to know: The behavior is different in Oracle 12c than in previous database versions.

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Ensemble Dinner

Ensemble modeling is a family of data modeling approaches optimized for data warehouse. Its basic idea is to break things into parts to increase flexibility and to change them independently. A group of people met in Stockholm to find the least common denominator of several ensemble modeling approaches. I had the luck to be invited to this “ensemble dinner”.

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