Create Spatial Layer-- Fields and controls

Use this window to define a new spatial layer on an existing table. If the table does not already have a column of spatial data type, or if you want to add a new column of spatial data type for this new spatial layer, the table will be altered to add the new spatial data column and the spatial layer will be defined on it.

Typically, if you are defining a new spatial layer on an existing table, you specify a new column to contain the spatial data. However, you can also use an existing spatial data column for the new spatial layer.

Layer column

Column type

Spatial reference name

Available columns

>, >>, <, <<

Selected columns

Enable automatic geocoder

Name

Precision level

Properties

OK

Cancel

Layer column

Use this box to specify the name of the table column for this spatial layer.

Use one of these methods:

• Select one of the columns of spatial data type in the table that is specified in the Layer table field. If you use an existing column, it must not already be registered as a spatial layer.

• Type a name for a new column into the box. If the column does not already exist, it will be created with the spatial data type that is specified in the Column type field.

Column type

Select the spatial data type for the column specified in the Layer column field. Choices are ST_Geometry or one of its subtypes.

If the spatial data column already exists, this field displays its type and you cannot change it.

If the column specified in the Layer column field does not already exist, you must choose a spatial data type for this column.

Spatial reference name

Use this box to specify the name of the spatial reference system to use for this spatial layer.

Use one of these methods to select the spatial reference system:

• Select an existing spatial reference system.
• Type in the name of a spatial reference system that exists on this database.

If no spatial reference system exists in this database, you must first create one by using the Create push button in the Spatial References window. To open the Spatial References window, right-click on the database and select Spatial Extender -> Spatial References from the pop-up menu.

Available columns

This box lists all of the columns defined for the table that you selected in the Control Center. You can optionally use this box to select the non-spatial columns that contain the source data to be passed to the geocoder for this spatial layer and then click the > push button. You can select one or more columns at the same time.

For example, if you have a table named CUSTOMERS that has the following columns:

and a column named LOCATION with spatial data type ST_Point, you could select the ADDRESS, CITY, STATE, and ZIP columns to have their data passed to the geocoder to be used for the spatial data column LOCATION. The geocoder transforms the information from the address format to the spatial format.

You can define up to 10 columns to be used as input to a geocoder. The order in which you select the columns is not important.

>, >>, <, <<

Use these push buttons to change the list of columns displayed in the Available columns and Selected columns boxes. You can use:

>

To move the selected columns in the Available columns box to the Selected columns box.

>>

To move all columns displayed in the Available columns box to the Selected columns box.

<

To move the selected columns in the Selected columns box to the Available columns box.

<<

To move all columns displayed in the Selected columns box to the Available columns box.

Selected columns

This box lists all of the columns that you selected to be used as input to a geocoder. These source columns define the source data to be passed to the geocoder. The data can contain free-form text information. The order of these columns is not important.

Enable automatic geocoder

Use this box to specify whether automatic geocoding is enabled. Automatic geocoding ensures the consistency between the non-spatial data (for example, an address) and spatial data (for example, a location). If automatic geocoding is specified for a spatial layer, triggers are created that will be invoked to populate the spatial data column whenever the source data for the selected columns is changed (inserted, deleted, or updated).

If there are a large number of rows in the table, it is usually more efficient to run the batch geocoder on them all at once instead of enabling the automatic geocoder to be triggered whenever a row is modified. To run the batch geocoder on a spatial layer, select the spatial layer in the Spatial Layers window and click Run Geocoder.

Name

Use this box to specify the name of the geocoder to be run for automatic geocoding. This box is available only when the Enable automatic geocoder check box is selected. The default value is the name of the geocoder that is shipped with the DB2 Universal Database Spatial Extender.

Use one of these methods:

• Select the name of a registered geocoder from the list.
• Type the name of a registered geocoder in the box.

Precision level

Use this box to specify the precision of the geocoding process. This box is available only when the Enable automatic geocoder check box is selected.

The range of the precision is from 1 (least precise; for example, city level) to 100 (most precise; for example, the house number that is identical to the matched record in the reference data). The default value is the value that is the default for the geocoder that you selected.

Use one of these methods to change the precision:

• Select the up or down arrows to spin through the available choices.

• Type in a value.

Properties

Optional: Use this box to provide any vendor-specific switches to control the geocoder. This box is available only when the Enable automatic geocoder check box is selected. The default switches are those that are defaults for the selected geocoder.