Input: relationship table

Output: attribute index table

Map (LongWritable, DataText, DataText, DataText)

Input: key:=entity ID, value:=tuple

FOR each (key, value) DO

FOR each property DO

output_key := property ID + “*” + property value

output_value := entity ID

Reduce (DataText, DataText, NullWritable, DataText)

FOR each value in value_table

entity ID:= property ID + “*” + entity ID

output_key:= null

output_value:= all of entity ID in value_table