Integration Server detects indexes (including bitmapped indexes) you have defined on source tables and uses them to create an Essbase outline and to load data. Indexes are pointers logically arranged by the values of a key. Indexes optimize access to relational data. Bitmapped indexes are specialized indexes that may improve performance during analysis of numeric data.
Define indexes on columns you use to filter data in the source database or in the OLAP model. For example, if the source database contains columns for city and state, and you filter on city or state (SELECT * FROM Region WHERE State = Ca%), then index the columns which you are filtering (here, State).
If you are creating and filtering on alias names, index the column containing alias names. See Creating Aliases for Dimensions and Members.
Define bitmapped indexes on numeric data you use to filter the database. For example, if you filter on sales values SELECT Product FROM ProdSales GROUPBY Product ORDERBY ProdId HAVING SUM(Sales)>15000, then consider defining a bitmapped index on sales values. Most source databases support bitmapped indexes. See the documentation for the RDBMS or data warehouse that you are using.