Join Product Skew

• In these experiments both the relations were skewed implying that a small number of repeats can cause a blow up in the result.

    Algo		    (10K Join 10)		    (1K Join 100)		 (100 Join 1000)


HH 		         143.6 		            144.0 		               144.0 

WRange 		   148.2 		          148.2 		              149.4 

VP-RR 		     49.7 		             85.8 		              151.0 

VP-RS 		     56.3 		             94.1 		              155.0 

• For the above results (table 4) the configuration was same as previous.
• Observations:
  (i) The VP-RR & VP-PS have significant success. This is explained by the fact that in the Range and Weighted Range algorithms the skew in the relation is not enough to cause tuples with '1's to be sent to more than one processor.
  (ii) In the case of *100 Join *1000 the round robin fails to distribute the 1's because there are so few in the building relation . The processor scheduling algo fails because it wrongly estimates the work requires per virtual processor.