1. SAGE Computing Services Customised Oracle Training Workshops and Consulting Creative Conditional Compilation … and raising the bar with your PL/SQL Scott Wesley Systems Consultant

3. The example everybodys seen…

4. PL/SQL Users Guide & Reference 10g Release 2 –Fundamentals of the PL/SQL Language Conditional Compilation

5. Availability 11g Release 1 10g Release 2 –Enabled out of the box 10.1.0.4 – Once patched, enabled by default –Disable using _parameter 9.2.0.6 – Once patched, disabled by default –Enable using _parameter

6. Catch 22 INDICES OF

7. Catch 22 Conditional Compilation Patch INDICES OF

8. Facilitates removal of unnecessary code at compile time Performance Readability Accuracy Testing It's cool!

9. Selection Directives $IF boolean_static_expression $THEN text [ $ELSIF boolean_static_expression $THEN text ] [ $ELSE text ] $END Inquiry Directives DBMS_OUTPUT.PUT_LINE($$PLSQL_LINE); ALTER SESSION SET PLSQL_CCFLAGS= ' max_sentence:100 ' ; IF sentence > $$max_sentence THEN Error Directives $IF $$PLSQL_OPTIMIZE_LEVEL != 2 $THEN $ERROR 'intensive_program must be compiled with maximum optimisation' $END Semantics

10. Inquiry Directives

11. > BEGIN DBMS_OUTPUT.PUT_LINE('Unit:'||$$PLSQL_UNIT); DBMS_OUTPUT.PUT_LINE('Line:'||$$PLSQL_LINE); END anon; / Unit: Line:4

12. > CREATE OR REPLACE PROCEDURE sw_test IS BEGIN DBMS_OUTPUT.PUT_LINE('Unit:'||$$PLSQL_UNIT); DBMS_OUTPUT.PUT_LINE('Line:'||$$PLSQL_LINE); END sw_test; / Procedure created. > exec sw_test Unit:SW_TEST Line:4

13. ALTER SESSION SET PLSQL_CCFLAGS = 'max_sentence:100'; Session altered.

14. > BEGIN IF p_sentence < $$max_sentence THEN DBMS_OUTPUT.PUT_LINE('Parole Available'); ELSE DBMS_OUTPUT.PUT_LINE('Life'); END IF; END; / Life

15. ALTER SYSTEM SET PLSQL_CCFLAGS = 'VARCHAR2_SIZE:100, DEF_APP_ERR:-20001'; DECLARE lc_variable_chr VARCHAR2($$VARCHAR2_SIZE); e_def_app_err EXCEPTION; PRAGMA EXCEPTION_INIT (e_def_app_err, $$DEF_APP_ERR); BEGIN --> rest of your code END anon; /

16. First Demo: Post-processed Source Demo: cc1.sql cc2.sql

17. Reuse Settings

18. ALTER SYSTEM SET PLSQL_CCFLAGS = 'MY_PI:314'; CREATE OR REPLACE PROCEDURE universe_alpha IS BEGIN DBMS_OUTPUT.PUT_LINE('Alpha pi = '||$$my_pi/100); END; CREATE OR REPLACE PROCEDURE universe_gamma IS BEGIN DBMS_OUTPUT.PUT_LINE('Gamma pi = '||$$my_pi/100); END; CREATE OR REPLACE PROCEDURE universe_oz IS BEGIN DBMS_OUTPUT.PUT_LINE('Oz pi = '||$$my_pi/100); END; ALTER PROCEDURE universe_alpha COMPILE PLSQL_CCFLAGS = 'MY_PI:289' REUSE SETTINGS; ALTER PROCEDURE universe_gamma COMPILE PLSQL_CCFLAGS = 'MY_PI:423' REUSE SETTINGS; > BEGIN universe_alpha; universe_gamma; universe_oz; END; / Alpha pi = 2.89 Gamma pi = 4.23 Oz pi = 3.14

19. Second Demo: Directive Usage Demo: cc3.sql cc4.sql cc5.sql

20. Some versioning examples?

21. Using new version code today $IF dbms_db_version.ver_le_10 $THEN -- version 10 and earlier code $ELSIF dbms_db_version.ver_le_11 $THEN -- version 11 code $ELSE -- version 12 and later code $END

22. 10.1 vs 10.2 dbms_output

23. CREATE OR REPLACE PROCEDURE sw_debug (p_text IN VARCHAR2) IS $IF $$sw_debug_on $THEN l_text VARCHAR2(32767); $END BEGIN $IF $$sw_debug_on $THEN -- Lets provide debugging info $IF dbms_db_version.ver_le_10_1 $THEN -- We have to truncate for <= 10.1 l_text := SUBSTR(p_text, 1,200); $ELSE l_text := p_text; $END DBMS_OUTPUT.PUT_LINE(p_text); $ELSE -- No debugging NULL; $END END sw_debug;

26. 10g vs 11g result_cache FUNCTION quantity_ordered (p_item_id IN items.item_id%TYPE) RETURN NUMBER $IF dbms_version.ver_le_10 $THEN -- nothing $ELSE RESULT_CACHE $END IS BEGIN...

27. 9i vs 10g Bulk Insert

28. CREATE OR REPLACE PACKAGE BODY sw_bulk_insert IS PROCEDURE sw_insert (sw_tab IN t_sw_tab) IS BEGIN $IF dbms_db_version.ver_le_9 $THEN DECLARE l_dense t_sw_tab; ln_index PLS_INTEGER := sw_tab.FIRST; BEGIN > WHILE (l_index IS NOT NULL) LOOP l_dense(l_dense.COUNT + 1) := sw_tab(l_index); l_index := sw_tab.NEXT(l_index); END LOOP dense_loop; FORALL i IN 1..l_dense.COUNT INSERT INTO sw_table VALUES l_dense(i); END; $ELSE FORALL i IN INDICES OF sw_tab INSERT INTO sw_table VALUES sw_tab(i); $END END sw_insert; END sw_bulk_insert;

31. Paradigm Examples

32. Latent debugging code

33. CREATE OR REPLACE PACKAGE pkg_debug IS debug_flag CONSTANT BOOLEAN := FALSE; END pkg_debug; / CREATE OR REPLACE PROCEDURE sw_proc IS BEGIN $IF pkg_debug.debug_flag $THEN dbms_output.put_line ('Debugging Details'); $END END sw_proc; /

34. Assertions ?

35. Assertions should be used to document logically impossible situations Development tool Testing Aid In-line Documentation if the impossible occurs, then something fundamental is clearly wrong. This is distinct from error handling. Run-time Cost

36. Latent Assertions ?

37. The removal of assertions from production code is almost always done automatically. It usually is done via conditional compilation. www.answers.com/topic/assert

38. $IF $$asserting OR CC_assertion.asserting $THEN IF p_param != c_pi*r*r THEN raise_application_error(.. END IF; $END -- individual program unit -- entire application

39. Testing subprograms only in package body

40. CREATE PACKAGE universe IS PROCEDURE create_sun; PROCEDURE create_planets; -- CC test procedure PROCEDURE test_orbit; END universe; CREATE PACKAGE BODY universe IS -- Private PROCEDURE orbit IS.. END; -- Public PROCEDURE create_sun IS.. END; PROCEDURE create_planets IS.. END; -- Testers PROCEDURE test_orbit IS BEGIN $IF $$testing $THEN orbit; $ELSE RAISE program_error; $END END test_orbit; END universe;

41. CREATE PACKAGE universe IS PROCEDURE create_sun; PROCEDURE create_planets; -- CC test sequence PROCEDURE test_run; END universe; CREATE PACKAGE BODY universe IS -- Private PROCEDURE orbit IS.. END; -- Public PROCEDURE create_sun IS.. END; PROCEDURE create_planets IS.. END; -- Test sequence PROCEDURE test_run IS BEGIN $IF $$testing $THEN create_sun; create_planets; orbit; $ELSE RAISE program_error; $END END test_run; END universe;

42. Mock objects

43. FUNCTION get_emp(p_emp_id IN emp.emp_id%TYPE) RETURN t_emp IS l_emp t_emp; BEGIN $IF $$mock_emp $THEN l_emp.emp_name := 'Scott';.. RETURN l_emp; $ELSE SELECT * FROM emp INTO l_emp WHERE emp_id = p_emp_id; RETURN l_emp; $END END get_emp;

44. Comparing competing implementations during prototyping

45. PROCEDURE xyz IS $IF $$alternative = 1 $THEN -- varray declaration $ELSIF $$alternative = 2 $THEN -- nested table declaration $END BEGIN $IF $$alternative = 1 $THEN -- simple varray solution $ELSIF $$alternative = 2 $THEN -- elegant nested table solution $END END xyz; $IF $$alternative = 1 $THEN -- first verbose solution that came to mind $ELSIF $$alternative = 2 $THEN -- some crazy idea you came up with at 3am you need to try out $END

46. Component Based Installation

47. PACKAGE BODY core IS PROCEDURE execute_component(p_choice IN VARCHAR2) IS BEGIN CASE p_choice -- Base is always installed. WHEN 'base' THEN base.main(); $IF CC_licence.cheap_installed $THEN WHEN 'cheap' THEN cheap.main(); $END... $IF CC_licence.pricey_installed $THEN WHEN 'pricey' THEN pricey.main(); $END END CASE; EXCEPTION WHEN case_not_found THEN dbms_output.put_line('Component '||p_choice||' is not installed.'); END execute_component; END core;

48. Get It Right with the Error Directive

49. $IF $$PLSQL_OPTIMIZE_LEVEL != 2 $THEN $ERROR 'intensive_program must be compiled with maximum optimisation' $END

50. BEGIN... /* * * Note to self: Must remember to finish this bit * */... END;

51. BEGIN... -- Jacko: this doesnt work, fix before moving to prod!... END;

52. 1 CREATE PROCEDURE process_court_outcome IS 2 BEGIN 3 IF lr_victim.age > 18 THEN 4 send_to_prison(lr_victim); 5 ELSE 6 $ERROR 7 'Waiting for business to advise '|| 8 $$PLSQL_UNIT||' line: '||$$PLSQL_LINE 9 $END 10 END IF; 11 END process_court_outcome; 12 / Warning: Procedure created with compilation errors. SQL> sho err LINE/COL ERROR -------- ---------------------------------------- 6/6 PLS-00179: $ERROR: Waiting for business to advise PROCESS_COURT_OUTCOME line: 8

53. CREATE OR REPLACE PACKAGE pkg_debug IS debug_flag CONSTANT BOOLEAN := FALSE; $IF $$CC_dev_notes $THEN PROCEDURE insert_dev_note(p_note IN VARCHAR2,p_unit IN VARCHAR2,p_line IN VARCHAR2) IS PRAGMA AUTONOMOUS TRANSACTION; BEGIN INSERT INTO dev_notes (note, unit, line) VALUES (p_note, p_unit, p_line); END insert_dev_note; $END END pkg_debug; /

54. CREATE PROCEDURE process_court_outcome IS BEGIN IF lr_victim.age > 18 THEN send_to_prison(lr_victim); ELSE pkg_debug.insert_dev_note ('Waiting for business to advise',$$PLSQL_UNIT,$$PLSQL_LINE); END IF; END process_court_outcome; /

55. Good Practices

56. Inquiry directives have null values for normal behaviour $IF $$cc_flag = 'x' $THEN cc_code; $END

57. Choose restriction type carefully $IF $$debug_on OR module_y.cc_debug $THEN sw_debug('Error'); $END

58. but theres always this...

59. SQL> define debug=/* begin &debug select 'conditionally' into :c1 from dual; -- */ select 'always' into :c2 from dual; end; /

60. SAGE Computing Services Customised Oracle Training Workshops and Consulting Questions and Answers? Presentations are available from our website: http://www.sagecomputing.com.au enquiries@sagecomputing.com.au scott.wesley@sagecomputing.com.au