On a Three-Way Hash Join Algorithm
نویسندگان
چکیده
We develop hash-based algorithms for computing a three-way join. The method involves hashing all three relations into buckets, and then joining buckets in main memory, three buckets at a time. Comparing to two-cascaded hash joins, the algorithms avoid materializing an intermediate result. We present a cost model for this approach, from which we identify the range of parameters for queries that beneet from our technique. We also validate our analysis with experimental results, comparing our approach to performing two hybrid-hash joins. This approach is almost always preferable to computing to consecutive GRACE hash joins, and in many cases it is also preferable to two consequtive hybrid-hash joins.
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