Use Unidirectional property to specify will application navigate by dataset records in forward-only direction or in forward and backward directions. To change Unidirectional for already used dataset, application may call Disconnect method first. 

Setting Unidirectional to True enables application to navigate in forward-only direction. AnyDAC will automatically discard prior rows from internal data storage after moving current position in dataset, because they are not needed anymore. That dramatically reduces memory consumption on big result sets. 

Setting Unidirectional to True for TADTable disables the live data window mode.

Do not use Unidirectional datasets to display data in grid control. It requires bi-directional datasets.

property Unidirectional: Boolean;

Fetching Rows, RowsetSize, Mode