skew is the mesaureof data flow to each partation .
suppose i/p is comming from 4 files and size is 1 gb
1 gb= ( 100mb+200mb+300mb+5oomb)
1000mb/4= 250 mb
(100- 250 )/500= --> -150/500 == cal ur self it wil come in -ve value.
calclu for 200,500,300.
+ve value of skew is allways desriable.
skew is a indericet measure of graph.   _{Your Comment}