Data Connection

Name of the Data Connection for the Tag History Provider.

Enabled

If the check box is selected (enabled), the provider is turned on and accepts tag history data.

If disabled, the database is not shown in the list of history providers when configuring tag history from the Designer. Also, any data logged to the provider, will error out and be quarantined by the store and forward engine, if possible.

Enable Partitioning

To improve query performance, Tag Historian can partition the data based on time. Partitions will only be queried if the query time range includes their data, thereby avoiding partitions that aren't applicable and reducing database processing. On the other hand, the system must execute a query per partition. It is therefore best to avoid both very large partitions, and partitions that are too small and fragment the data too much. When choosing a partition size, it is also useful to examine the most common time span of queries.

Partition Length and Units

The size of each partition, the default is one month. Many systems whose primary goal is to show only recent data might use smaller values, such as a week, or even a day.

Enable Data Pruning

Partitions with data older than a specific age are deleted. The check box is not selected/enabled by default.

Important: Data pruning works by deleting old partitions. Therefore, data will only be removed when a partition has no data younger than the prune age.

Prune Age and Units

The maximum age of data. As mentioned, the data is deleted by the partition, and could therefore surpass this threshold by quite a bit before all of the data in the partition is old enough to be dropped.