Processing multi-way theta join queries involving arithmetic operators on MapReduce

A computer program product, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a computing device to cause the computing device to:

• convert (i) a multi-way theta join query on MapReduce into a multi-way interval join query on MapReduce, and (ii) one or more items of data associated with the multi-way theta join query to one or more items of interval data;
• execute the multi-way interval join query on the one or more items of interval data via MapReduce to generate an output, wherein the output comprises a set of multiple responses to the multi-way interval join query;
• and
• process the output to generate a solution to the multi-way theta join query, wherein said processing comprises discarding each response from the set that does not satisfy the multi-way theta join query.

A system comprising:

• a memory;
• and
• at least one processor coupled to the memory and configured for:
• converting (i) a multi-way theta join query on MapReduce into a multi-way interval join query on MapReduce, and (ii) one or more items of data associated with the multi-way theta join query to one or more items of interval data;
• executing the multi-way interval join query on the one or more items of interval data via MapReduce to generate an output, wherein the output comprises a set of multiple responses to the multi-way interval join query;
• and
• processing the output to generate a solution to the multi-way theta join query, wherein said processing comprises discarding each response from the set that does not satisfy the multi-way theta join query.

A method comprising:

• converting a multi-way theta join query on MapReduce into a multi-way interval join query on MapReduce, wherein the multi-way theta join query comprises one or more join conditions involving one or more arithmetic operators on one or more items of real-valued data;
• optimizing the multi-way interval join query to reduce the number of conditions in the multi-way interval join query that include the one or more arithmetic operators;
• executing the optimized multi-way interval join query via MapReduce to generate an output;
• and
• processing the output to generate a solution in response to the optimized multi-way theta join query;
• wherein said converting, said optimizing, said executing, and said processing are carried out by at least one computing device.