User's Guide and Reference

Defining a spatial column for a table, registering this column as a layer, and enabling a geocoder to maintain it

This section gives an overview of the steps to define a spatial column for a table, register this column as a layer, and enable a geocoder to maintain it. The overview is followed by details of how to complete each step.

To find out what authorization you need to register a table column as a layer, see Authorization. To find out what authorization you need to enable a geocoder to maintain this column, see Authorization.

Overview of steps to define a spatial column for a table, register this column as a layer, and enable a geocoder to maintain it:

1. If the spatial column is to be part of a new table, create this table.
2. Open the Create Spatial Layer window.
3. Either add a spatial column to a table, and indicate that you want to register this column as a layer; or indicate that you want to register an existing column as a layer.
4. Indicate which spatial reference system is to be used for the layer.
5. If the layer is to contain imported data, or data that is generated from another spatial column, tell DB2 Spatial Extender to create the layer.
6. If the layer is to contain data derived from attribute data:
   1. Specify which column or columns contain this attribute data.
   2. Indicate that you want to enable a geocoder to maintain the layer.
   3. Tell DB2 Spatial Extender to create the layer.

Detailed steps to define a spatial column for a table, register this column as a layer, and enable a geocoder to maintain it:

1. If the spatial column is to be part of a new table, create this table:
   • Use an interface of your choice (for example, the Control Center or the Command Line Processor) to create the table.
   • If you plan to use a geocoder, include one to ten columns for the geocoder to operate on. A geocoder cannot take more than ten columns of data as input.
   • Either include the spatial column that you will be registering as a layer, or define this column in step 3.

   If you want to use an existing table, go on to the next step.

2. Open the Create Spatial Layer window.
   1. From the Control Center window, expand the object tree until you find the Tables folder for the tables in the database that you use for spatial operations.
   2. Click the Tables folder. The tables are displayed in the contents pane on the right side of the window.
   3. Right-click the table that you want and click Spatial Extender --> Spatial Layers in the pop-up menu. The Spatial Layers window opens.
   4. From the Spatial Layers window, click Create. The Create Spatial Layer window opens.
3. From the Create Spatial Layer window, either add a spatial column to a table, and indicate that you want to register this column as a layer; or indicate that you want to register an existing column as a layer.
   • If you want to add a spatial column to a table and define this column as a layer:
     1. In the Layer column field, type a name for the column.
     2. In the Column type field, select or type the data type that you want the column to have. For a discussion of allowable data types, see About spatial data types.
   • If you want to define an existing column as a layer, select it in the Layer column field.

     Restriction:

     Do not select a column that has already been defined as a layer.

4. In the Spatial reference name field, specify the name of the spatial reference system to be used for the layer.
5. If you want the layer to contain imported data, or data that is generated from another spatial column, click OK to register it.
6. If you want the layer to contain data that is derived from attribute data:
   1. Specify which column or columns contain this attribute data:
      1. Select the column or columns in the Available columns box. You can select up to ten columns.
      2. Click the > push button, the >> push button, or both, to list the selected column or columns in the Selected columns box.
   2. If you want to enable a geocoder to maintain the layer:
      1. Select the Enable automatic geocoder check box.
      2. In the Name field, select the name of the geocoder that you want to use.
      3. In the Precision level field, specify, in terms of percentage, the degree to which input records must match corresponding records in the reference data in order to be processed. This percentage is called a precision. For example, suppose that the geocoder reads an input record that contains the address, 557 Bailey, San Jose 94120. If the precision is 100, and if the match between this address and its counterpart in the reference data is not 100 percent accurate, the geocoder will reject it. If the precision is 75, and the match between the record and its reference data counterpart is at least 75 percent accurate, the geocoder will process it.
      4. If the geocoder was supplied by a vendor, use the Properties box to specify any vendor-supplied geocoding parameters that you want to use.
   3. Click OK to register the selected column as a layer and, if you requested it, to enable the geocoder to maintain the column.