Database Connection
Database
This is the reader dataset. When you enter the Database in the reader dataset field, it will be automatically added to this parameter.
Constraints
Table List
After you have specified the database connection, click the Browse button to select tables for import. A connection window appears while the system compiles a table from the database.
Once the table list appears, you can select one or more tables, and then click OK to dismiss the window. The table name(s) will appear in the Table List field in the parameter box.
WHERE Clause
An SQL WHERE clause can be applied to the selected tables, to constrain the the row selection in tables chosen in the table list (for example, NUMLANES=2).
Schema Attributes
Additional Attributes to Expose
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, you can use this parameter to expose additional attributes on multiple feature types.
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 set to 10, the reader reads ten rows into local memory, and processes features from this memory buffer. After the reading the last row, the reader retrieves the next 10 rows from the data source.
This parameter will result in significantly degraded performance if incorrectly set. 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 default value has been determined optimal.