Pre-computed results, such as measurements that have been aggregated (usually summed) over a set of dimensional characteristics, are stored in aggregate tables. Aggregate tables are a widely used approach in decision support systems for reducing query response times.
For example, if you notice that most queries are fired on aggregated values such as yearly or monthly data rather than day level data, you can create an aggregate table containing month level and year level data, map it to the appropriate logical table, and set the aggregation levels in the content tab of LTS to speed up the report.