Data Sources Statistics

In addition to gathering query frequencies, an internal statistics component periodically scans the following parameters of the original data sources:

1. Table statistics
   
   1. total number of records
2. Column statistics
   
   1. number of distinct values throughout the column
   2. number of null values throughout the column (where applicable)
   3. minimum column value (where applicable)
   4. maximum column value (where applicable)

The gathered statistics can help the query engine make the right decision for optimizing queries in many cases.

The CData Virtuality Server has several special stored procedures for gathering statistics which are collected on a dedicated page.