Main |
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Provider Name | Name of the Tag History Provider. By default, this will match up with the name of the database connection. |
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. |
Description | A user created description of the provider. |
Data Partitioning |
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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. |
Enabled Pre-processed Partitions | Enables pre-processed partitions. |
Pre-processed Window Size (seconds) | When pre-processed partitions is turned on, this setting defines the window size. |
Data Pruning |
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Enable Data Pruning | Partitions with data older than a specific age are deleted. The check box is not selected/enabled by default.
Note: Data pruning works by deleting old partitions. Therefore, data will only be removed when a partition has no data younger than the prune age.
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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. |
Advanced |
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Enable Stale Data Detection | If enabled, tracks Tag Group executions to determine the difference between unchanging values, and values that are flat due to the system not running. |
Stale Detection Multiplier | The multiplier for Tag Group rate used to determine when values are stale. If Tag Group execution is not recorded within this amount of time, values will be considered bad on query. |