## Uses of Class
org.apache.sysds.runtime.compress.colgroup.APreAgg

- Packages that use APreAgg
  Package | Description
  --- | ---
  org.apache.sysds.runtime.compress.colgroup |

- - ### Uses of APreAgg in org.apache.sysds.runtime.compress.colgroup

    Subclasses of APreAgg in org.apache.sysds.runtime.compress.colgroup
    Modifier and Type | Class | Description
    --- | --- | ---
    `class` | `ASDCZero` |
    `class` | `ColGroupDDC` | Class to encapsulate information about a column group that is encoded with dense dictionary encoding (DDC).
    `class` | `ColGroupDeltaDDC` | Class to encapsulate information about a column group that is first delta encoded then encoded with dense dictionary encoding (DeltaDDC).
    `class` | `ColGroupSDCSingleZeros` | Column group that sparsely encodes the dictionary values.
    `class` | `ColGroupSDCZeros` | Column group that sparsely encodes the dictionary values.

    Methods in org.apache.sysds.runtime.compress.colgroup with parameters of type APreAgg
    Modifier and Type | Method | Description
    --- | --- | ---
    `ADictionary` | APreAgg.`preAggregateThatIndexStructure​(APreAgg that)` | Pre aggregate into a dictionary.