Data WareHouse

The Data Warehouse consists of Oracle tables created to facilitate reporting. There are three types of tables in the Data Warehouse:

  • Aleph Oracle tables, which currently make up the majority of data in the Data Warehouse. The Aleph Oracle tables are not normalized for reporting often making it difficult to create complex reports. ETL (extract/transform/load) scripts are run nightly to pull selected data elements from the Aleph Oracle tables, normalize them for reporting, and load them into a separate Oracle database (the Data Warehouse). Another issue with using the Aleph Oracle tables for reporting is that the Aleph code is sitll dependant on an old version of the Oracle optimizer called the Rule Based Optimizer (RBO). The newer Oracle optimizer is called the Cost Based Optimizer (CBO) and it is usually more effective for ad-hoc queries. The Data Warehouse Oracle instance is configured with the CBO.
  • SFX search records taken from both the current SFX tables and archived files providing the ability to create more comprehensive reports.
  • Tabled versions of NOTIS records used for reporting prior to the conversion to Aleph.
Data Warehouse Table Information