Oracle Database: Nova funcionalidade no SQL Text Expansion e procedure EXPAND_SQL_TEXT

SQL Text Expansion

No Oracle Database 12c, foi introduzida uma nova funcionalidade, o SQL Text Expansion. E na package DBMS_UTILITY, foi adicionada a procedure EXPAND_SQL_TEXT.

SQL> variable retornoclob
SQL> begin 
dbms_utility.expand_sql_text( input_sql_text => 
'select * from emp', output_sql_text=> :retorno );
end;
/

PL/SQL procedure successfully completed.

SQL> print retorno

RETORNO
-------------------------------------------------------------------------------
SELECT "A1"."EMPNO" "EMPNO","A1"."ENAME" "ENAME","A1"."JOB" "JOB","A1"."MGR" "MGR","A1"."HIREDATE" "HIREDATE","A1"."SAL" "SAL","A1"."COMM" "COMM","A1"."DEPTNO""DEPTNO" FROM "SCOTT"."EMP" "A1"

Vamos verificar o efeito com uma política de VPD:

SQL> SELECT count(*)
 FROM emp e, dept d
 WHERE d.deptno = e.deptno;

COUNT(*)
---------
14

Criando a política de VPD, para mostrar apenas os dados referentes ao departamento 30:

SQL> CREATE OR REPLACE FUNCTION hide_sal_comm ( v_schema IN VARCHAR2, v_objname IN VARCHAR2)
RETURN VARCHAR2 AS
con VARCHAR2 (200);

BEGIN
 con := 'deptno=30';
 RETURN (con);
END hide_sal_comm;
/ 

Function created.

SQL> BEGIN
 DBMS_RLS.ADD_POLICY ( object_schema => 'scott', object_name => 'emp',
policy_name => 'hide_sal_policy', policy_function => 'hide_sal_comm');

END;
/

PL/SQL procedure successfully completed.

SQL> SELECT count(*)
 FROM emp e, dept d
 WHERE d.deptno = e.deptno;

COUNT(*)
----------
6

Verificando o SQL gerado:

SQL> variable retornoclob

SQL> begin 
dbms_utility.expand_sql_text(;input_sql_text=> 
'SELECT count(*) FROM empe,depd WHEREd.deptno = e.deptno', output_sql_text => :retorno );
end;
/

PL/SQL procedure successfully completed.

SQL> print retorno

RETORNO
--------------------------------------------------------------------------------
SELECT COUNT(*) "COUNT(*)" FROM (SELECT "A3"."EMPNO" "EMPNO","A3"."ENAME" "ENAME","A3"."JOB" "JOB","A3"."MGR" "MGR","A3"."HIREDATE" "HIREDATE","A3"."SAL" "SAL","A3"."COMM" "COMM","A3"."DEPTNO" "DEPTNO" FROM "SCOTT"."EMP" "A3" WHERE "A3"."DEPTNO"=30)  "A2","SCOTT"."DEPT" "A1" WHERE "A1"."DEPTNO"="A2"."DEPTNO"

Abraço