/// <exception cref="System.IO.IOException"></exception>
public override void Open()
{
_mappingDb = DefragmentServicesImpl.FreshTempFile(_fileName, 1);
_idTree = (_treeSpec == null ? new BTree(Trans(), 0, new MappedIDPairHandler()) :
new BTree(Trans(), 0, new MappedIDPairHandler(), _treeSpec.NodeSize()));
_slotTree = (_treeSpec == null ? new BTree(Trans(), 0, new BTreeIdSystem.IdSlotMappingHandler
()) : new BTree(Trans(), 0, new BTreeIdSystem.IdSlotMappingHandler(), _treeSpec.
NodeSize()));
}
