concept: Data Skew - davidkhala/data-warehouse GitHub Wiki

Data skew means the data is not distributed evenly across the distributions

• some distributions finish their portion of a parallel query before others. Since the query can't complete until all distributions have finished processing, each query is only as fast as the slowest distribution.

• 一个处理器核心承担的工作比其他处理器核心多得多，进而成为瓶颈