1·Consider only the most important columns for the most important queries that have selection predicates for these distribution statistics.
对于这些分布统计信息，只考虑对拥有选择谓词的最重要的查询而言最为重要的列。
2·You have learned how to analyze and tune the problem query from the perspective of statistics, predicates, and indexes.
您已经了解如何从统计数据、谓词和索引这几方面来分析和调优问题查询。
3·The predicates work like this: for each node, the engine processes the predicate using that context.
谓词的工作原理类似于：对于每个节点，引擎使用上下文处理谓词。
4·You may choose to include some of the filter predicates in MQTs if you think that your queries would always filter data using the same constant value.
如果您认为自己的查询总是使用相同的常量值过滤数据，那么您可能选择在MQT中包含一些过滤器谓词。
5·These additional source columns, combined with additional source join predicates in user queries, help the rewrite phase identify joins that will not produce any join results.
这些附加的源列，加上用户查询中附加的源连接谓词，可以帮助重写阶段识别不会产生任何连接结果的连接。