7 Using PL/Scope

Specifying Identifier Collection

By default, PL/Scope does not collect data for identifiers in the PL/SQL source program. To have PL/Scope collect data for all identifiers in the PL/SQL source program, including identifiers in package bodies, set the PL/SQL compilation parameter PLSCOPE_SETTINGS to 'IDENTIFIERS:ALL'.

PL/Scope stores the data that it collects in the SYSAUX tablespace. If the SYSAUX tablespace is unavailable, and you compile a program unit with PLSCOPE_SETTINGS='IDENTIFIERS:ALL', PL/Scope does not collect data for the compiled object. The compiler does not issue a warning, but it saves a warning in USER_ERRORS.

PL/Scope Identifier Data for STANDARD and DBMS_STANDARD

The packages STANDARD and DBMS_STANDARD declare and define base types, such as VARCHAR2 and NUMBER, and subprograms such as RAISE_APPLICATION_ERROR. If your database has PL/Scope identifier data for these packages, PL/Scope can track your usage of the identifiers that these packages create.

Do You Need STANDARD and DBMS_STANDARD Identifier Data?

You can use PL/Scope without STANDARD and DBMS_STANDARD identifier data. You need this data only if you must know where your code uses the base types or subprograms that these packages create—for example, to know where your code uses the base type BINARY_INTEGER, so that you can substitute PLS_INTEGER.

Does Your Database Have STANDARD and DBMS_STANDARD Identifier Data?

A newly created Oracle Database 11g Release 1 (11.1.0.7), or a database that was upgraded to 11.1.0.7 from Oracle Database 10g Release 2, has PL/Scope identifier data for the packages STANDARD and DBMS_STANDARD. A database that was upgraded to 11.1.0.7 from 11.1.0.6 does not have this data.

To see if your database has this data, use the query in Example 7-1.

Example 7-1 shows what the query returns when the database has PL/Scope identifier data for STANDARD and DBMS_STANDARD.

SELECT UNIQUE OBJECT_NAME
FROM ALL_IDENTIFIERS
WHERE OBJECT_NAME IN ('STANDARD', 'DBMS_STANDARD')
AND OWNER='SYS'
ORDER BY OBJECT_NAME;
 

OBJECT_NAME
------------------------------
DBMS_STANDARD
STANDARD
 
2 rows selected.

If the query in Example 7-1 selects no rows, then the database does not have PL/Scope identifier data for the packages STANDARD and DBMS_STANDARD. To collect this data, a DBA must recompile the packages STANDARD and DBMS_STANDARD, as explained in "Recompiling STANDARD and DBMS_STANDARD".

Recompiling STANDARD and DBMS_STANDARD

A DBA can use this procedure to recompile the packages STANDARD and DBMS_STANDARD:

1. Connect to the database, shut it down, and then start it in UPGRADE mode:

   CONNECT / AS SYSDBA;
   SHUTDOWN IMMEDIATE;
   STARTUP PFILE=parameter_initialization_file UPGRADE;
   

2. Have PL/Scope collect data for all identifiers in the packages STANDARD and DBMS_STANDARD:

   ALTER SESSION SET PLSCOPE_SETTINGS='IDENTIFIERS:ALL';
   

3. Invalidate and recompile the database:

   @?/rdbms/admin/utlirp.sql
   

   Now all PL/SQL objects in the database are invalid except STANDARD and DBMS_STANDARD, which were recompiled with PLSCOPE_SETTINGS='IDENTIFIERS:ALL'.

4. (Optional) Invalidate any other PL/SQL objects to be recompiled with PLSCOPE_SETTINGS='IDENTIFIERS:ALL', using a script similar to this.

   Customize the query on lines 5 through 9 to invalidate only those objects for which you need PL/Scope identifier data. Collecting all identifiers for all objects, as this script does, might generate large amounts of data and slow compile time:

   DECLARE
     TYPE ObjIDArray IS TABLE OF NUMBER INDEX BY BINARY_INTEGER;
     ObjIDs  ObjIDArray;
   BEGIN
     SELECT object_id BULK COLLECT INTO ObjIDs
     FROM ALL_OBJECTS
     WHERE object_type IN
       (SELECT DISTINCT TYPE
        FROM ALL_PLSQL_OBJECT_SETTINGS);
     FOR i IN 1..SQL%ROWCOUNT LOOP
       BEGIN
         DBMS_UTILITY.INVALIDATE(ObjIDs(i),
           'PLSCOPE_SETTINGS=IDENTIFIERS:ALL REUSE SETTINGS');
         NULL;
       END;
     END LOOP;
   END;
   /
   

   Notes:

   In the preceding script:

   • Do not substitute ObjIDs.LAST for SQL%ROWCOUNT, because ObjIDs attributes are dependent on a package that is locked by the anonymous block.

   • If your database is large, do not substitute a cursor FOR LOOP for the BULK COLLECT statement, or you will run out of resources.

5. Shut down the database, and then start it in NORMAL mode:

   SHUTDOWN IMMEDIATE;
   STARTUP PFILE=parameter_initialization_file;
   

6. For any remaining invalid PL/SQL objects, do either of these:

   • Allow them to be recompiled automatically, as they are referenced.

     (This can be slow if there are complex dependencies.)

   • Run the script utlrp.sql to recompile the invalid PL/SQL objects, as explained in "Running utlrp.sql to Recompile Invalid PL/SQL Objects".

Running utlrp.sql to Recompile Invalid PL/SQL Objects

If the database was restarted in NORMAL mode (step 5), then a DBA, or a user who has been granted the DBA role, can use this procedure:

1. Connect to the database as SYS:

   CONNECT / AS SYS;
   

2. Run the script utlrp.sql:

   @?/rdbms/admin/utlrp.sql
   

   If the script gives you any instructions, follow them, and then run the script again.

   If the script terminates abnormally without giving any instructions, run it again.

How Much Space is PL/Scope Data Using?

PL/Scope stores its data in the SYSAUX tablespace. If you are logged on as SYSDBA, you can use the query in Example 7-2 to display the amount of space that PL/Scope data is using.

SELECT SPACE_USAGE_KBYTES
FROM V$SYSAUX_OCCUPANTS
WHERE OCCUPANT_NAME='PL/SCOPE';
 

SPACE_USAGE_KBYTES
------------------
              1600
 
1 row selected.

For information about managing the SYSAUX tablespace, see Oracle Database Administrator's Guide.

Viewing PL/Scope Data

To view the data that PL/Scope has collected, you can use either:

• Static Data Dictionary Views

• Demo Tool

• SQL Developer

ALTER SESSION SET PLSCOPE_SETTINGS = 'IDENTIFIERS:ALL';

CREATE OR REPLACE PROCEDURE a (p1 IN BOOLEAN) IS
  v PLS_INTEGER;
BEGIN
  v := 42;
  DBMS_OUTPUT.PUT_LINE(v);
  RAISE_APPLICATION_ERROR (-20000, 'Bad');
EXCEPTION
  WHEN Program_Error THEN NULL;
END a;
/
CREATE OR REPLACE PROCEDURE b (p2 OUT PLS_INTEGER, p3 IN OUT VARCHAR2) IS
  n NUMBER;
  q BOOLEAN := TRUE;
BEGIN
  FOR j IN 1..5 LOOP
    a(q); a(TRUE); a(TRUE);
    IF j > 2 THEN
       GOTO z;
    END IF;
  END LOOP;
<<z>> DECLARE
  d CONSTANT CHAR(1) := 'X';
  BEGIN
    SELECT COUNT(*) INTO n FROM Dual WHERE Dummy = d;
  END z;
END b;
/
WITH v AS (
  SELECT    Line,
            Col,
            INITCAP(NAME) Name,
            LOWER(TYPE)   Type,
            LOWER(USAGE)  Usage,
            USAGE_ID,
            USAGE_CONTEXT_ID
    FROM USER_IDENTIFIERS
      WHERE Object_Name = 'B'
        AND Object_Type = 'PROCEDURE'
)
SELECT RPAD(LPAD(' ', 2*(Level-1)) ||
                 Name, 20, '.')||' '||
                 RPAD(Type, 20)||
                 RPAD(Usage, 20)
                 IDENTIFIER_USAGE_CONTEXTS
  FROM v
  START WITH USAGE_CONTEXT_ID = 0
  CONNECT BY PRIOR USAGE_ID = USAGE_CONTEXT_ID
  ORDER SIBLINGS BY Line, Col
/

IDENTIFIER_USAGE_CONTEXTS
-------------------------------------------------------------
B................... procedure           declaration
  B................. procedure           definition
    P2.............. formal out          declaration
      Pls_Integer... subtype             reference
    P3.............. formal in out       declaration
      Varchar2...... character datatype  reference
    N............... variable            declaration
      Number........ number datatype     reference
    Q............... variable            declaration
      Q............. variable            assignment
      Boolean....... boolean datatype    reference
    J............... iterator            declaration
      A............. procedure           call
        Q........... variable            reference
      A............. procedure           call
      A............. procedure           call
      J............. iterator            reference
      Z............. label               reference
    Z............... label               declaration
      D............. constant            declaration
        D........... constant            assignment
        Char........ subtype             reference
      N............. variable            assignment
      D............. constant            reference
 
24 rows selected.

CREATE OR REPLACE PROCEDURE p IS
  PROCEDURE p IS
  BEGIN
    DBMS_OUTPUT.PUT_LINE('Inner p');
  END p;
BEGIN
  DBMS_OUTPUT.PUT_LINE('Outer p');
  p();
END p;
/

Identifier Types that PL/Scope Collects

Table 7-1 shows the identifier types that PL/Scope collects, in alphabetical order. The identifier types in Table 7-1 appear in the TYPE column of the *_IDENTIFIER static data dictionary views, which are described in Oracle Database Reference.

Usages that PL/Scope Reports

Table 7-2 shows the usages that PL/Scope reports, in alphabetical order. The identifier types in Table 7-2 appear in the USAGE column of the *_IDENTIFIER static data dictionary views, which are described in Oracle Database Reference.

Sample PL/Scope Session

In this sample session, assume that you are logged in as HR.

1. Set the session parameter:

   ALTER SESSION SET PLSCOPE_SETTINGS='IDENTIFIERS:ALL';
   

2. Create this package:

   CREATE OR REPLACE PACKAGE PACK1 IS
     TYPE r1 is RECORD (rf1 VARCHAR2(10));
     FUNCTION F1(fp1 NUMBER) RETURN NUMBER;
     PROCEDURE P1(pp1 VARCHAR2);
   END PACK1;
   /
   CREATE OR REPLACE PACKAGE BODY PACK1 IS
     FUNCTION F1(fp1 NUMBER) RETURN NUMBER IS
       a NUMBER := 10;
     BEGIN
       RETURN a;
     END F1;
     PROCEDURE P1(pp1 VARCHAR2) IS
       pr1 r1;
     BEGIN
       pr1.rf1 := pp1;
     END;
   END PACK1;
   /
   

3. Verify that PL/Scope collected all identifiers for the package body:

   SELECT PLSCOPE_SETTINGS
   FROM USER_PLSQL_OBJECT_SETTINGS
   WHERE NAME='PACK1' AND TYPE='PACKAGE BODY'
   

   Result:

   PLSCOPE_SETTINGS
   ------------------------------------------------------------------------
   IDENTIFIERS:ALL
   

4. Display unique identifiers in HR by querying for all DECLARATION usages. For example, to see all unique identifiers with name like %1, use these SQL*Plus formatting commands and this query:

   COLUMN NAME FORMAT A6
   COLUMN SIGNATURE FORMAT A32
   COLUMN TYPE FORMAT A9
   
   SELECT NAME, SIGNATURE, TYPE
   FROM USER_IDENTIFIERS
   WHERE NAME LIKE '%1' AND USAGE='DECLARATION'
   ORDER BY OBJECT_TYPE, USAGE_ID;
   

   Result is similar to:

   NAME   SIGNATURE                        TYPE
   ------ -------------------------------- ---------
   PACK1  41820FA4D5EF6BE707895178D0C5C4EF PACKAGE
   R1     EEBB6849DEE31BC77BF186EBAE5D4E2D RECORD
   RF1    41D70040337349634A7F547BC83517C7 VARIABLE
   F1     4559CF050A5F5C3E5F5FFDD0D9D55EFA FUNCTION
   FP1    CAC3474C112DBEC67AB926978D9A16C1 FORMAL IN
   P1     B7C0576BA4D00C33A65CC0C64CADAB89 PROCEDURE
   PP1    6B74CF95A5B7377A735925DFAA280266 FORMAL IN
   FP1    98EB63B8A4AFEB5EF94D50A20165D6CC FORMAL IN
   PP1    AD89FE0EAE9CE5D6D48AA4684E0D57DF FORMAL IN
   PR1    1B5117F30E8DAE0261A02CAA5E33883F VARIABLE
    
   10 rows selected.
   

   The *_IDENTIFIERS static data dictionary views display only basic type names; for example, the TYPE of a local variable or record field is VARIABLE. To determine the exact type of a VARIABLE, you must use its USAGE_CONTEXT_ID.

5. Find all local variables:

   COLUMN VARIABLE_NAME FORMAT A13
   COLUMN CONTEXT_NAME FORMAT A12
   
   SELECT a.NAME variable_name,
           b.NAME context_name,
           a.SIGNATURE
   FROM USER_IDENTIFIERS a, USER_IDENTIFIERS b
   WHERE a.USAGE_CONTEXT_ID = b.USAGE_ID
   AND a.TYPE = 'VARIABLE'
   AND a.USAGE = 'DECLARATION'
   AND a.OBJECT_NAME = 'PACK1'
   AND a.OBJECT_NAME = b.OBJECT_NAME
   AND a.OBJECT_TYPE =  b.OBJECT_TYPE
   AND (b.TYPE = 'FUNCTION' or b.TYPE = 'PROCEDURE')
   ORDER BY a.OBJECT_TYPE, a.USAGE_ID;
   

   Result is similar to:

   VARIABLE_NAME CONTEXT_NAME SIGNATURE
   ------------- ------------ --------------------------------
   A             F1           1691C6B3C951FCAA2CBEEB47F85CF128
   PR1           P1           1B5117F30E8DAE0261A02CAA5E33883F
    
   2 rows selected.
   
   

6. Find all usages performed on the local variable A:

   COLUMN USAGE FORMAT A11
   COLUMN USAGE_ID FORMAT 999
   COLUMN OBJECT_NAME FORMAT A11
   COLUMN OBJECT_TYPE FORMAT A12
   
   SELECT USAGE, USAGE_ID, OBJECT_NAME, OBJECT_TYPE
   FROM USER_IDENTIFIERS
   WHERE SIGNATURE='1691C6B3C951FCAA2CBEEB47F85CF128'  -- signature of A
   ORDER BY OBJECT_TYPE, USAGE_ID;
   

   Result:

   USAGE       USAGE_ID OBJECT_NAME OBJECT_TYPE
   ----------- -------- ----------- ------------
   DECLARATION        6 PACK1       PACKAGE BODY
   ASSIGNMENT         8 PACK1       PACKAGE BODY
   REFERENCE          9 PACK1       PACKAGE BODY
    
   3 rows selected.
   

   The usages performed on the local identifier A are the identifier declaration (USAGE_ID 6), an assignment (USAGE_ID 8), and a reference (USAGE_ID 9).

7. From the declaration of the local identifier A, find its type:

   COLUMN NAME FORMAT A6
   COLUMN TYPE FORMAT A15
   
   SELECT a.NAME, a.TYPE
   FROM USER_IDENTIFIERS a, USER_IDENTIFIERS b
   WHERE a.USAGE = 'REFERENCE'
   AND a.USAGE_CONTEXT_ID = b.USAGE_ID
   AND b.USAGE = 'DECLARATION'
   AND b.SIGNATURE = '4559CF050A5F5C3E5F5FFDD0D9D55EFA'  -- signature of F1
   AND a.OBJECT_TYPE = b.OBJECT_TYPE
   AND a.OBJECT_NAME = b.OBJECT_NAME;
   

   Result:

   NAME   TYPE
   ------ ---------------
   NUMBER NUMBER DATATYPE
    
   1 row selected.
   

   Note:

   This query produces the output shown only if your database has PL/Scope identifier data for the packages STANDARD and DBMS_STANDARD. For more information, see "PL/Scope Identifier Data for STANDARD and DBMS_STANDARD".

8. Find out where the assignment to local identifier A occurred:

   SELECT LINE, COL, OBJECT_NAME, OBJECT_TYPE
   FROM USER_IDENTIFIERS
   WHERE SIGNATURE='1691C6B3C951FCAA2CBEEB47F85CF128'  -- signature of A
   AND USAGE='ASSIGNMENT';
   

   Result:

         LINE        COL OBJECT_NAME OBJECT_TYPE
   ---------- ---------- ----------- ------------
            3          5 PACK1       PACKAGE BODY
    
   1 row selected.