gvSIG-Desktop 1.12. User manual
The Locate Duplicates tool can be used to quickly locate duplicate geometries in a layer's attribute table.
To locate duplicate geometries in a layer, open the layer's attribute table and select the field (by clicking on its header) for which you want to select duplicates.
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Then click on the "Select Duplicates" button.
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Select Duplicates button
Notice that the selected geometries have duplicate attribute values for the specified field:
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