A datasource is a collection used to store various types of datasets, such as point, line, region data, TIN, GRID, Network, etc. A datasource can contain one or more datasets of different types, which can be vector datasets or raster datasets. All data is stored in the datasource, not in the workspace.
supports opening and creating new file datasources and EMS datasources. An EMS datasource is a type of temporary data source in the file database.
File Database
Stores spatial data and attribute data directly in files, supporting UDB and UDBX types of file databases. Using file databases for map display is faster with small data volumes, and data migration is convenient.
The file engines supported by the file database include four types: SuperMap's custom UDB engine (read-write), UDBX engine (read-write), image plugin engine (directly accessing some image data), and vector file engine (directly accessing external vector files).
- UDB Engine, is a file-based spatial data engine in the custom format of SuperMap Objects. This engine adopts a traditional hybrid storage approach of files and databases. A UDB engine data project includes two files: the file with the extension UDB uses OLE compound document technology to store spatial data; the file with the extension UDD uses the MDB database format of Access to store attribute data. The compound document technology used in UDB files provides the capability to store multiple datasets within a single UDB project. This differs from technologies like ArcInfo Coverage and MapInfo Table files. UDB primarily targets small to medium-sized systems and desktop applications, aiming to improve efficiency and compensate for the shortcomings of pure database engines in this regard.
- UDBX Engine, can read, write, and manage Spatialite spatial data. Spatialite is an open-source library that extends the SQLite kernel, providing a complete and powerful spatial database management system with cross-platform and lightweight features, and supports fully mature spatial SQL functionality. Additionally, Spatialite uses R-Tree as the spatial index to achieve efficient retrieval of spatial data. The newly added UDBX file engine in SuperMap fully leverages Spatialite's capabilities for efficient spatial data management and the characteristics of a lightweight database.
- Using the UDBX file engine does not require installing or deploying a database system. Since a Spatialite database corresponds to a single file with no file size limitations, creating a datasource with the UDBX file engine will generate a UDBX file database (*.udbx), which is essentially a database file. It offers more openness, safer data operations, and greater stability compared to existing UDB file databases.
- In a UDBX file database, you can create datasets or import data from other sources. Dataset types supported by the UDBX file database include: point, line, region, and mosaic datasets.
- The UDBX file engine is more open and supports direct operations on spatial data imported from third-party sources into Spatialite spatial databases, such as display and data editing. Simply load the Spatialite spatial database file (*.sqlite) as a file database into the desktop software.
- Image Plugin Engine, supports read-only display of raster-type data in SuperMap. Currently supported formats include BMP, JPEG, RAW, TIFF, SCI, SIT, and ERDAS IMAGINE raster data types (BMP and JPEG are common raster data types; RAW and TIFF are remote sensing image data types; SCI is a map pre-cache picture file defined by SuperMap; SIT is a raster data type defined by SuperMap). Thus, the plugin engine includes the following seven types: BMP read-only engine, JPG read-only engine, RAW read-only engine, TIFF read-only engine, SCI read-only engine, SIT read-only engine, and ERDAS IMAGINE read-only engine.
- Vector File Engine, targets common vector formats such as SHP, TAB, DWG, etc., supporting editing and saving of some vector files.
| File Database Engine Types | |
| Type | Description |
| UDB | UDB type, for UDB datasources. |
| UDBX | UDBX file engine, can read, write, and manage Spatialite spatial data, for UDBX datasources. Supported dataset types include: point, line, region, text, CAD, attribute table, 3D point/line/region, EPS composite point/line/region/text, raster, image, mosaic dataset. |
| ImagePlugins | Image plugins engine type, for common image formats such as BMP, JPG, TIFF, and SuperMap's custom image format SIT, etc. |
| Vector File | Vector file engine class, for common vector formats such as SHP, TAB, DWG, etc., supporting editing and saving of vector files. |
EMS Datasource
Data in the EMS datasource is stored in memory, serving as a temporary data source that does not support saving. The corresponding data engine is the memory engine. Intermediate results from some analyses can be stored in this datasource, improving analysis efficiency. When final data is obtained, it can be exported from the EMS datasource to local data.
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