Landing nested tables

Qlik Data Gateway - Data Movement supports the landing of Oracle tables containing columns that are nested tables or defined types. To enable this functionality, select the Support nested tables option in the Advanced tab.

If a captured nested table is added to an existing parent table (captured or not captured), Data Movement gateway will handle it correctly, but the non-unique index for the corresponding target table will not be created. Note that in this case, if the target child table becomes extremely large, performance may be impacted. In such a case, it is recommended to stop the task, create the index, and then resume the task.

Prerequisites

Make sure that you Land parent tables for all the landed nested tables. Both the parent tables (the tables containing the nested table column) and the child (i.e. nested) tables will be available for selection in Data Movement gateway.

Supported nested table types

The following nested table types are supported:

• Data type
• User defined Object

Limitations

• Only one level of nesting is supported.
• Data Movement gateway does not verify that both the parent and child table(s) are selected for landing. In other words, it's possible to select a parent table without a child and vice versa.

How nested tables are landed

The parent and nested tables are landed to the target as follows:

• The parent table is created identical to the source. The nested column will be defined as RAW(16) and contain a reference to its nested tables in the NESTED_TABLE_ID column.

• The child table is created identical to the source, but with an additional column named NESTED_TABLE_ID with the same type as the parent nested column and with the same meaning.