TimeSeries collect indexing

The performance of queries against the TimeSeries collect Historical table, which is often heavily used, directly affects the performance of trends in the easy eXtended Operator Station (ezXOS). This section describes an investigation into how introducing new column indexes to the TimeSeries.dbo.collect table affects the performance of queries against the table.

Since introducing new indexes can have some negative impact, the following was investigated:

• Performance times for queries that read, insert, and delete rows from the table.

• The disk space requirements with the addition of new indexes.

This section will describe:

• The specifications of the test system.

• The tests performed.

• The results of each test.

Each test was run both before and after the addition of the new indexes to provide a basis of comparison.