Each table consists of data elements that describe or qualify an item of business significance. The collection also has a Person table with data elements such as SSN, name, birth date, etc. Because the data is stored in tables, it is easy to access just the data you need, rather than having to plow through all the data in the data collection. A table may be a part of more than one data collection. Note that some data elements in tables are indexed.
Indexing enables the system to execute queries faster.
A query with a record selection condition using an indexed data element tells the system to go directly to the rows in the table that contain the value indicated and to stop retrieving data when the value is no longer found. If a query does not select records based on an indexed data element in its record selection condition, the system starts searching at the first row in the table and works through every row until it reaches the last row in the table. Thus, queries that do not use indexed data elements for record selection will run slowly. Table Help Help documentation is available for each table in the Warehouse. Help describes the basic contents of the table.