Does outer join usage a performance hit ?
Hi,
I have my table in which organization Id is present. I join with Organizations (Master table) to get the Organization name.
Because, entering an Organization is optional in my UI, i end up doing and outer join with the master table. However i can do my design without outer join (A facility available in my framwork..which basically forms a correlated subquery).
When I take the explain plan (with and without outer joins over different volumes of data)there is no difference in the explain plan or neither the method of scanning of table.
To tell u my problem in sql terms -
Method 1
Select mytable.id, master.name from tab1 mytable, tab2 master where mytable.id=master.id(+)
Method 2
Select mytable.id, (select master.name from tab2 master where master.id= mytable.id) from tab1;
Which among both of thse queries would be efficient , In a bulk data case.
Please help me with this design descision.
Regards,
Suman