The optimizer will then join that temp table to the fact table using the compoundindex to quickly locate the rows that satisfy the criteria on the dimension tables.
优化器然后使用复合索引将临时表连接到事实表，来快速定位在维度表中满足条件的行。
2
We keep only a compound primary key and a secondary index for each row, and answer all queries from a single index.
我们只保留了一个组合主键和一个辅助索引来完成所有的查询。
3
Better control over manual indexing and index writing (RAM consumption, non-compound file format flag etc).