Question : PL/SQL Performance

I have a question on SQL performance for JOINs.

I usually right JOINS like the following

Select * from a, b, c
where a.1 = b.2 and b.1 = c.1

What is the difference between using this on the JOIN on syntax? Is it faster, more efficient or best practice?

Thank you

Answer : PL/SQL Performance

explain plan shows the execution path that Oracle will take to run your query.  You can generate one and view it like this...

explain plan for
<your query here>

then query

select * from table(dbms_xplan.display)  -- yes, this exact syntax, immediately after running the explain plan.


for example

explain plan for
Select * from a, b, c
where a.1 = b.2 and b.1 = c.1;

select * from table(dbms_xplan.display);


explain plan for
Select * from a join b on a.1 = b.2 join c on b.1=c.1;

select * from table(dbms_xplan.display);