Read Spatial Data allows you to access data from a named table and use it as input in a data flow.
The Read Spatial Data stage allows you to read spatial data using MI SQL functions (SELECT, FROM with multiple tables for joins, WHERE, GROUP BY, ORDER BY, LIMIT, and OFFSET). The named tables you are reading from must be present in the repository before using them with MI SQL in this stage.
The difference between the Read Spatial Data and Query Spatial Data stages is that the Read Spatial Data stage is a source stage that has no upstream stage connected. The Query Spatial Data stage, however, requires an upstream stage that can pass in query parameters for the query. Auto-complete displays functions and operators to facilitate query construction.
To use this stage, enter the MI SQL query statement in the text area and click Verify. You can also specify a number of runtime instances (see the Dataflow Designer's Guide for detailed information on runtime performance options).