Application of Filters to Multiway Joins in MapReduce

Algorithm 3

Increasing a coordinate.

(1) procedure  INCRCOORD(𝑐𝑜𝑜𝑟𝑑[1,…,𝑛],𝑗𝑜𝑖𝑛𝐴𝑡𝑡𝑟[1,…,𝑛],𝑟𝑒𝑝𝑙[1,…,𝑛])

(2)  for  𝑖=1 to 𝑛  do

(3)   if  𝑗𝑜𝑖𝑛𝐴𝑡𝑡𝑟[𝑖] is not null then

(4)    continue

(5)   end if

(6)   𝑐𝑜𝑜𝑟𝑑[𝑖]←𝑐𝑜𝑜𝑟𝑑[𝑖]+1

(7)   if  𝑐𝑜𝑜𝑟𝑑[𝑖]<𝑟𝑒𝑝𝑙[𝑖]  then

(8)    return  𝑡𝑟𝑢𝑒

(9)   end if

(10)   𝑐𝑜𝑜𝑟𝑑[𝑖]←0

(11)  end for

(12)  return  𝑓𝑎𝑙𝑠𝑒

(13) end procedure