8i join and 10g ANSI join syntax

From: Prasath <prasath.rao_at_gmail.com>
Date: 2 Feb 2006 03:12:02 -0800
Message-ID: <1138878722.590425.72310@g14g2000cwa.googlegroups.com>

SQL> desc dept
Name Type

SQL> desc emp
Name Type

------------------- EMPNO NUMBER(4) ENAME VARCHAR2(10) JOB VARCHAR2(9) MGR NUMBER(4) HIREDATE DATE SAL NUMBER(7,2) COMM NUMBER(7,2) DEPTNO NUMBER(2)

QUERY 1

SQL> select emp.ename, dept.dname
  2 from emp, dept
  3 where emp.deptno =dept.deptno
  4 and emp.hiredate > ( sysdate - 300 );

ENAME DNAME
---------- --------------

ADAMS      RESEARCH
SCOTT      RESEARCH



---------------------------------------------

QUERY 2

SQL> select emp.ename, dept.dname
2 from emp inner join dept on emp.deptno =dept.deptno and emp.hiredate > ( sysdate - 300 );

ENAME DNAME
---------- --------------

ADAMS      RESEARCH
SCOTT      RESEARCH

Question

I know that both query 1 and 2 produce the same results. Are they handled as similar queries internally by Oracle? The explain plan was same though.
Is the filter 'emp.hiredate > ( sysdate - 300 )' applied on queries 1 and 2 before the join is made?

Thanks,
Prasath. Received on Thu Feb 02 2006 - 05:12:02 CST