Query times for complex decision support are directly impacted by increases in data volume. A large portion of a table may need to be read, so if the table doubles in size, the effort required to process the work can also double. However, a query that accesses one or a small number of rows in the database is not impacted by changes to the data volume. Typically, a tactical query accesses one or a small number of rows whether the table is 1 GB or 10 TB.