4 Setting the Array Handling Policy

This chapter contains the following sections:

Setting the Default Behavior for Array Handling
Modifying the Default Behavior During Metadata Import
Modifying the Array Handling Policy for a Specific Table

4.1 Setting the Default Behavior for Array Handling

You can define the default behavior for array handling at the data source level when configuring the data source properties.

See Oracle Database Gateway for IMS, VSAM, and Adabas Installation and Configuration Guide for Microsoft Windows or Oracle Database Gateway for IMS, VSAM, and Adabas Installation and Configuration Guide for UNIX for details on configuring data source properties.

Perform the following steps to set the default behavior:

Right-click the data source and select Edit Data Source.

The Configuration Properties screen opens.
On the Advanced tab, in the Virtual View Policy section, configure how arrays will be handled by selecting the relevant check boxes. The following options are available:
- Generate sequential view: Select this option if you want to map a non-relation file to a single table.
- Generate virtual views: Select this option if you want to have an individual table created for every array in the non-relational file.
- Include row number column: Select this option if you want to include a column that specifies the row number in the virtual or sequential view.
- Inherit all parent columns: Select this option if you want the virtual views to include all the columns of the parent record.
Figure 4-1 Setting the Default Behavior for Handling Arrays
Save your settings.

4.2 Modifying the Default Behavior During Metadata Import

During the metadata import procedure, the Metadata Model Selection step lets you modify the array handling policy for the tables to be imported. You can define specific settings per table or keep the default values, which are inherited from the settings that you defined on the data source level (see Setting the Default Behavior for Array Handling). After importing a table, you can change its array handling settings on the Modeling tab of the table editor (see Modifying the Array Handling Policy for a Specific Table).

Perform the following steps to select the metadata model.

In the Import Wizard, click Next until you reach the Metadata Model Selection step.
Select from the following:
- Default values for all tables: Select this option if you want to apply the same values to all tables to be imported.
  
  Note:
  Selecting this check box discards all table-specific settings.
  - Generate sequential view: Select this option if you want to map a non-relation file to a single table.
  - Generate virtual views: Select this option if you want to have an individual table created for every array in the non-relational file.
  - Virtual views include row number: Select this option if you want to include a column that specifies the row number in the virtual or sequential view.
  - Virtual views inherit all parent columns: Select this option if you want the virtual views to include all the columns of the parent record.
- Specific virtual array view settings per table: Select this option if you want to apply different values to the tables to be imported. Then select the relevant check boxes.
Figure 4-2 Selecting the Metadata Model
Click Next to continue to the next step, then click Finish.

4.3 Modifying the Array Handling Policy for a Specific Table

You can also change the array handling policy on the table level. Perform the following steps to modify the policy for a specific table:

Right-click the data source and select Edit metadata.

The Metadata view opens on the node of the respective data source.
Expand the data source node, and then expand the Tables node.
Double-click the table whose array handling settings you want to modify.

The table editor opens.
On the Modeling tab, configure how arrays will be handled by selecting the relevant check boxes. The following options are available:
- Generate sequential view: Select this option if you want to map a non-relation file to a single table.
- Generate virtual views: Select this option if you want to have an individual table created for every array in the non-relational file.
- Include row number column: Select this option if you want to include a column that specifies the row number in the virtual or sequential view.
- Inherit all parent columns: Select this option if you want the virtual views to include all the columns of the parent record.
Figure 4-3 Modifying the Array Handling Policy on the Table Level
Save your settings.

Oracle Studio for IMS, VSAM, and Adabas Gateways creates new virtual views.