Oracle Corporation
EARLY GROUPING OPTIMIZATION FOR SQL STATEMENTS WITH CONDITIONAL EXPRESSIONS

Abstract:

To increase the applicability of group-by placement (GBP) transformations, according to embodiments described herein, database objects referred to in the aggregate function expression of a query are analyzed to determine whether any of these database objects are referred to exclusively within a condition check portion of the aggregate function expression. Such database objects may be dealt with differently (i.e., with respect to inclusion in GBP views) than the rest of the database objects referred to in aggregate function expressions of the query. This distinction between (a) aggregation-condition database objects exclusively found in condition check portions of an aggregate function expression and (b) aggregation-source database objects within an aggregate function expression allows application of GBP transformation to a wider variety of queries and also increases the possible GBP states that can be costed for GBP transformation-eligible queries.