Optimizing Foreign Key JOINs For Large Fact Tables

Let’s continue our discussion of foreign-key-based JOINs using the example in the previous article.
If a fact table is too big to be held by the memory, the foreign key address-alization strategy will fail because the external storage cannot store the pre-calculated addresses.
Generally, a dimension table referred by a foreign key is small while an ever-increasing fact table is much larger. By loading the smaller dimension table into the memory, we can create temporary foreign key pointers.

The first two steps are the same as those for an in-memory computation. In step 4, switch from values t...