Select 36 columns versus Count(*) High difference in performance why?
I am selecting 36 columns from two tables
with simple join condition which is taking
more than 30 minutes.
Both tables are indexed.
from tableA,TableB where tableA.Column1=TableB.column8;
But If I issue the
same above query with count(*) it is coming in less than a second.
select count(*) from
tableA,TableB where tableA.Column1=TableB.column8;
What is the problem here..?
Immediate responses will be highly appriciated..