Extract Data Source
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Extract Data Source is a compressed snapshot of data from a regular data source.
This data is saved to a local file and can be updated from the original data source at any time.
The extract data file is optimized for data grouping. It reduces the initial dashboard load time.
The Extract Data Source improves performance when a complex query or a stored procedure takes a significant amount of time to get data from a database.
The Dashboard API provides the DashboardExtractDataSource class that can be used as any other Dashboard.DataSources. You should specify the original data source and the extract data file.
A special in-memory cache allows you to improve performance when accessing extract data. You can use the static class ExtractCacheOptions to specify a cache type for better results.
You can read files from any directory by default. To protect your application, use the AccessSettings class to explicitly specify where data sources can be read from. To accomplish this, configure rules in the DataResources property to restrict file system access to specified folders. You can call the SetRules(IAccessRule[]) method when your application starts to specify rules before a dashboard control sets its rules. The SetRules(IAccessRule[]) method can be called only once at application startup. Otherwise, the method will raise an exception. Alternatively, you can use the TrySetRules(IAccessRule[]) method, which does not raise an exception.
The following topics are available:
Data Types Supported by DashboardExtractDataSource
Note that DashboardExtractDataSource can process data fields of the following types when creating a data extract.
- Byte
- SByte
- Int16
- Int32
- Int64
- UInt16
- UInt32
- UInt64
- Single
- Double
- Decimal
- Boolean
- Char
- Guid
- DateTime
- TimeSpan
- String