Microsoft Access Reader Parameters
Database Connections |
---|
Connections store authentication information. For general information about sharing database connections, please see Using Database Connections. Note that different subsets of Database Connection parameters are made available in different contexts. Connection
Select an existing connection, or Add Database Connection to define a new connection. The new connection can be made visible only to the current user, or can be shared among multiple users. |
Database Connection
Select the location of the database.
This parameter is only required for Access databases with password protection.
Constraints
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.
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
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 where you have multiple feature types, it is convenient to expose additional attributes using this one parameter. For example, if you have ten feature types and want to expose the same attribute in each one, it is easier to define it once than it is to set each feature type individually in the workspace.
Advanced
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 10 rows into local memory. As features are processed, the reader returns the data from the local memory buffer. When the reader passes the last row available in local memory, it retrieves the next 10 rows from the data source.
This parameter may cause significantly degraded reader 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 to retrieve. The default setting of 10 has been determined to be the optimal value for average datasets.