Oracle Business Intelligence Suite, Enterprise Edition (OBIEE) is a set of advanced BI solutions using Oracle as the back-end database (DB) for staging visualizations like these:
Processing data in Oracle, however, is inherently inefficient. Oracle is designed for storage and retrieval, not the huge transforms which necessitate complex tuning and continual hardware upgrades -- or costly alternatives like Exadata or Hadoop.
Thus, rather than taxing Oracle users or shifting to appliances or other risky fabrics to accelerate an inefficient architecture, consider centralizing OBIEE data preparation in the file system you have. Central data preparation frees the DB from repeated transformation activities, and frees BI users from the burden of data integration for every report job.
Core components in the IRI Voracity data management platform such as IRI CoSort -- and its SortCL program in particular -- are proven offline engines for Oracle (and other big data source) table extraction, transformation, loading (ETL), and related Oracle data management. SortCL's numerous data transformation functions run much faster outside Oracle - either in the file system or Hadoop. Robust data masking and test data generation are also part of this environment. In fact, you can combine data manipulation in masking as you prepare data for presentation.
Beyond versatility and velocity is ease-of-use. SortCL's 4GL job scripts are far simpler and smaller than PL/SQL procedures, and they can be auto-created, deployed, and managed from a free, familiar Eclipse GUI. Both IT (ETL) and BI users find SortCL to be a simpler way to make data ready for reporting and analysis.
See this article about the benefits of centralized data preparation (or franchising) for BI. Consider how much sooner you can produce reusable tables and files from big data that's ready for OBIEE to ingest ... without affecting query performance.