Treatment history is stored in the UA_Treatment table in the
Campaign system table database, and is used together with contact history to form a complete historical record of offers sent to IDs in cells, and the specific details of each sent offer's attributes.
Cell membership is recorded in the UA_ContactHistory table for the appropriate audience level and the treatment(s) given to each cell are recorded in the
UA_Treatment table. This is a highly compressed and efficient way to store complete historical information. For example, if all 10,000 people in a cell receive the same three offers, rather than writing 3 * 10,000 = 30,000 records to contact history, 10,000 rows are written to contact history recording the individuals within the cell, and 3 rows are written to the
UA_Treatment table representing the treatments.