| CompressedSizeInfoColGroup | CompressedSizeEstimator. estimateCompressedColGroupSize()Method used for compressing into one type of colGroup | 
| abstract CompressedSizeInfoColGroup | CompressedSizeEstimator. estimateCompressedColGroupSize(int[] colIndexes)Abstract method for extracting Compressed Size Info of specified columns, together in a single ColGroup | 
| CompressedSizeInfoColGroup | CompressedSizeEstimatorSample. estimateCompressedColGroupSize(int[] colIndexes) | 
| CompressedSizeInfoColGroup | CompressedSizeEstimatorExact. estimateCompressedColGroupSize(int[] colIndexes) | 
| CompressedSizeInfoColGroup | CompressedSizeInfo. getGroupInfo(int index) |