Amazon Redshift Reader Parameters
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Database formats include a Database Connection parameter that defines and stores authentication information. For general information about sharing database connections, please see Using Database Connections. Note that Database Connection parameters differ slightly, depending on context and/or database format. |
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Connection From the Connection parameter in a database format, you can do one of the following:
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Schemas are used to organize tables. This parameter provides the list of viewable schemas.
If this parameter is left blank, the Tables dialog will only show choices from the search path for the current user. Selecting specific schemas here will cause tables from those schemas to be shown instead.
This parameter also specifies the schemas to fetch candidate tables when merging feature types. If it is not set, candidate tables are fetched based on the search path for the current user.
Connection Parameters
This specifies the machine running the Redshift ORDBMS as either an IP address or host name. The database must have proper permissions and be set up to accept TCP/IP connections if connecting from a remote machine.
When connecting remotely, this specifies the TCP/IP port on which to connect to the ORDBMS service. The default port is 5432.
This specifies the name of the Redshift database. The database must exist in the ORDBMS.
Enter the username and password to access the service.
Constraints
After specifying the database connection, click the Browse button (...) to select tables for import. A connection window appears while the system retrieves the tables from the database.
Once the Select Tables dialog appears, you can select one or more tables. Click OK to dismiss the window and add the selected table name(s) to the Tables parameter.
Schema Attributes
Use this parameter to expose Format Attributes in FME Workbench when you create a workspace:
- In a dynamic scenario, it means these attributes can be passed to the output dataset at runtime.
- In a non-dynamic scenario, this parameter allows you to expose additional attributes on multiple feature types. Click the browse button to view the available format attributes (which are different for each format) for the reader.
Spatial
Coordinate systems may be extracted from input feature data sources, may come predefined with FME, or may be user-defined. FME allows different output and input coordinate systems, and performs the required coordinate conversions when necessary.
If a coordinate system is specified in both the source format and the workspace, the coordinate system in the workspace is used. The coordinate system specified in the source format is not used, and a warning is logged. If a source coordinate system is not specified in the workspace and the format or system does not store coordinate system information, then the coordinate system is not set for the features that are read.
If a destination coordinate system is set and the feature has been tagged with a coordinate system, then a coordinate system conversion is performed to put the feature into the destination system. This happens right before the feature enters into the writer.
If the destination coordinate system was not set, then the features are written out in their original coordinate system.
If a destination coordinate system is set, but the source coordinate system was not specified in the workspace or stored in the source format, then no conversion is performed. The features are simply tagged with the output system name before being written to the output dataset.
For systems that know their coordinate system, the Coordinate System field will display Read from Source and FME will read the coordinate system from the source dataset. For most other input sources, the field will display Unknown (which simply means that FME will use default values). In most cases, the default value is all you'll need to perform the translation.
You can always choose to override the defaults and choose a new coordinate system. Select More Coordinate Systems from the drop-down menu to open the Coordinate System Gallery.
Changing a Reprojection
To perform a reprojection, FME typically uses the CS-MAP reprojection engine, which includes definitions for thousands of coordinate systems, with a large variety of projections, datums, ellipsoids, and units. However, GIS applications have slightly different algorithms for reprojecting data between different coordinate systems. To ensure that the data FME writes matches exactly to your existing data, you can use the reprojection engine from a different application.
To change the reprojection engine, Select Workspace Parameters > Spatial > Reprojection Engine. In the example shown, you can select Esri (but the selection here depends on your installed applications):
- The coordinate systems file coordsys.db in the FME installation folder contains the names and descriptions of all predefined coordinate systems.
- Some users may wish to use coordinate systems that do not ship with FME, and in those cases, FME also supports custom coordinate systems.
- Learn more about Working with Coordinate Systems in FME.
Advanced
The number of rows that are retrieved at one time into local memory from the data source. For example, if the value is set to 10000, the reader reads 10,000 rows into local memory, and processes features from this memory buffer. After the reading the last row, the reader retrieves the next 10,000 rows from the data source.