Also, DB2 cannot use random order index columns as part of a sort merge join.
另外,DB 2无法在排序合并合并连接中使用随机顺序的索引列。
2
As shown in the IXSCAN descriptor in Figure 8, the leading column of the index exploited by optimizer is PRODUCT_NUMBER, which does not provide the order required for merge scan join.
In fact they must release energy in that way in order to degrade their orbits and get close enough to merge. Those gravitational waves could act sort of like a jet engine, explained Jonker.