I have a query of the below format.
select a.id, c.name b.test_code from table1 a left outer join table2 b on (a.code1=b.code1 and a.code2=b.code2) inner join table3 c on (c.code1=a.code1 and c.code2=b.code2)
The skew factor of the above query is like around 95%.
The data volume in the table3 is also not so huge ( 4000 records )and the primary index are the fields used in the joins (cd3 and cd2).
I tried creating a temporary table as below
select a.id, b.test_code from table1 a left outer join table2 b on (a.cd1=b.cd1 and a.cd2=b.cd2)
and then join with the table3.
But still I was not able to see any change in the skew factor.
In both the cases, the data gets retrieved in ~11 seconds.
Please guide me on how i can reduce the skew factor in the above case.
Let me know if more details are needed.
Thanks In Advance,