Amazon Redshift Spatial Reader Parameters

About Database Connections

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.

Connection

From the Connection parameter in a database format, you can do one of the following:

  • Select an existing, previously defined connection. See the section Reusing a Database Connection in Using Database Connections
  • Select Add Database Connection to define a new connection. See database-specific parameters below, as well as the section Adding a Database Connection in a Workspace in Using Database Connections The new connection can be made visible only to the current user, or can be shared among multiple users.

Database Connection

Select an existing Redshift database connection, or Add Database Connection...

Add Redshift Database Connection

To define a new connection from the Connection parameter in a Redshift Spatial format, see the topic Amazon Redshift Spatial: Add Database Connection

Schemas for Tables

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.

Constraints

Tables

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.

Read Geometry As

Use this parameter to direct FME to read geometry from the database as either Hex Encoded Well-Known Binary (WKB) or Well-Known Text (WKT). Note that the final representation of features is the same with both methods.

  • Hex Encoded WKB – Use this setting to read Geometry as Hex Encoded WKB from the database. This is the default reading method for the reader.
  • WKT – Use this setting to read Geometry as WKT. With this mode active, reading speed may be slower and transfer bandwidth may be reduced. With this mode active, very large geometries have a possibility of throwing a database exception.

Use this parameter to expose Format Attributes in 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.

Advanced

Number Of Records To Fetch At A Time

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.

Note: If this parameter is incorrectly set, it will cause significantly degraded performance. The optimum value depends primarily on the characteristics of individual records and the transport between the database and the client machine. It is less affected by the quantity of rows that are to be retrieved. The optimal value is the default value set for the format, and these values vary widely (for example, 1 for PostGIS Raster; 10 for Microsoft SQL Server; 10000 for PostGIS and Redshift).