aggregation queries的用法和樣例：
例句
- Based on randomizing techniques, this paper discussed how the sketch-based approach estimates approximate answers to aggregate queries.
摘要討論了基於草圖的複雜聚集查詢的近似處理演算法。 - HierPrefixCube retains advantages on computation and organization of PrefixCube, and it can directly support aggregate queries on levels of the dimension hierarchy.
它不僅保留了前綴立方在計算和組織結構上的優點，又能直接和充分支持維層次級的聚集查詢。
