ยท Active Transformation
ยท Joiner relates two or more tables.
ยท It allows homogeneous or heterogeneous sources.
ยท Join Types
NORMAL (Equijoin โ default)
OUTER
รผ Master Outer
รผ Detail Outer
รผ Full Outer
ยท Does not allow non-equi joins.
Join Types
Equi-Join
Example
EMP (DETAIL )
Empno ename sal deptno
1 x 2000 10
2 y 3000 20
3 z 1000 10
4 A 3000
DEPT (MASTER)
DEPTNO DEPTNAME
10 HR
20 FI
30 SALES
Equi-Join (3 Records)
1 x 2000 10 HR
2 y 3000 20 FI
3 z 1000 10 HR
MASTER OUTER
Equi-Join + Remaining Records of Detail (4 records)
1 x 2000 10 HR
2 y 3000 20 FI
3 z 1000 10 HR
4 A 3000
Detail Outer
Equi-Join + Remaining Records of MASTER (4 records)
1 x 2000 10 HR
2 y 3000 20 FI
3 z 1000 10 HR
30 SALES
Full Outer
Equi-Join + Remaining Records of MASTER + Remaining Records of Detail (5 records)
1 x 2000 10 HR
2 y 3000 20 FI
3 z 1000 10 HR
30 SALES
4 A 3000
Interview Question for JOINER
Does JOINER allow non-equi-join?
Ans: NO It does not allow non-equi-joiN.
Create a table DIM_JOIN in the DWH_MEEN schema.
CREATE TABLE DIM_JOIN AS
SELECT * FROM EMP
WHERE 1=2;
Table structure only gets copied.
Alter the table and add a new column DNAME.
SQL> ALTER TABLE DIM_JOIN
ADD DNAME VARCHAR2(30);
Table altered.
SQL> DESC DIM_JOIN;
Name Null? 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)
DNAME VARCHAR2(30)
SQL> COMMIT;
Import that table in the Warehouse Designer.
SQL> select * from scott.emp;
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
---------- ---------- --------- ---------- --------- ---------- ---------- ----------
7499 ALLEN SALESMAN 7698 20-FEB-81 1600 300 30
7521 WARD SALESMAN 7698 22-FEB-81 1250 500 30
7566 JONES MANAGER 7839 02-APR-81 2975 20
7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400 30
7698 BLAKE MANAGER 7839 01-MAY-81 2850 30
7782 CLARK MANAGER 7839 09-JUN-81 2450 10
7788 SCOTT ANALYST 7566 19-APR-87 3000 20
7839 KING PRESIDENT 17-NOV-81 5000 10
7844 TURNER SALESMAN 7698 08-SEP-81 1500 0 30
7876 ADAMS CLERK 7788 23-MAY-87 1100 20
7900 JAMES CLERK 7698 03-DEC-81 950 30
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
---------- ---------- --------- ---------- --------- ---------- ---------- ----------
7902 FORD ANALYST 7566 03-DEC-81 3000 20
7934 MILLER CLERK 7782 23-JAN-82 1300 10
9999 MONA ANALYST 7566 06-AUG-09 2000
14 rows selected.
SQL> select * from scott.dept;
DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON
50 SUPPORT BANGALORE
60 DISTRIBUTION DELHI
70 EDUCATION CHENNAI
80 XYZ ABC
8 rows selected.
STEPS:
1. Define Sources (EMP,DEPT)
2. Define Target (DIM_JOIN)
3. Define Mapping (M_JOIN)โ Drag two sources and one target in Mapping Designer Workspace.
4. From the Transformation Menu select JOINER and create. T_JOIN
Drag the required ports from two source qualifiers to the JOINER.
Note: The first input to JOINER becomes Master and next Detail. (??? I got the detail as detail and master as master only )
Go to JOINER,edit โ go to PORTS tab and select master port for deptno,dname and loc.
Ports: Input,Output,MAster
Go to the Conditions tab and add a new condition.
Go to the Condition Tab and add a condition.
From the master table and detail table select the common column.
(Common column with common data type and size)
We can also add multiple conditions in a JOIN condition.
Properties:
ยท Data Cache
ยท Index Cache is going to use JOIN condition.
ยท Sorted Input
ยท Join Type
ยท Join Condition
ยท Cache Directory
ยท Case sensitive string comparison
ยท Join Type : NORMAL
ยท NULL ordering in MASTER/DETAIL (By default it is high โ NULL values will come at the bottom)
Project the required ports from JOINER to TARGET.
Validate the mapping.
Repository -> Save
Define session, workflow WF_JOIN.
Start workflow and preview the output.
NOTE: For JOINER and some other transformations, we can edit the properties at the Session level also.
Edit the Session and go to Mappings tab.
Select Transformations.
Master outer
(Equijoin + Remaining records of Detail Table)
Select the Join Type as Master Outer.
Repository -> Save.
Output (13 + 1)
DETAIL OUTER JOIN
Equijoin + Remaining Records of Master Table
(13 + 5 = 18)
Repository -> Save
Output:
FULL OUTER JOIN
(Equijoin + Remaining Records of Master + Remaining Records of Detail)
(13 + 5 + 1 = 19)
Output:

Comments
Post a Comment