Asset and data schema
- Last UpdatedFeb 07, 2023
- 1 minute read
- PI System
- PI OLEDB Enterprise 2019
- Developer
Four tables in the upper part of the diagram show the Asset schema that forms the core of the asset database representation: ElementHierarchy, Element, ElementVersion and ElementAttribute.
Note: Tables that support element versions have a "v" prefix.
Tables and Table-Valued Functions (TVFs) in the lower part of the diagram show the Data schema that represents the gateway to time-series data.
The Asset.vElementHierarchy table is usually the starting point for most queries. This table represents the element hierarchy and supports retrieval of elements based on various criteria, such as query date, path pattern or hierarchy level restriction, and so on.
Typically, queries into Asset.vElementHierarchy are extended as follows:
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Element attribute query = inner join of Asset.vElementHierarchy, Asset.vElementVersion, and Asset.vElementAttribute.
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Element extended property query = inner join of Asset.vElementHierarchy, Asset.vElementVersion, and Asset.vElementExtendedProperty.
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Time-series data query = inner join Asset.vElementHierarchy, Asset.vElementVersion, Asset.vElementAttribute, and any one table from the Data schema.