11g Features

8/3/2019 11g Features

1/19

PL/SQL New Features and Enhancements in

Oracle Database 11g Release 1

Oracle 11g includes a substantial number of PL/SQL new features and enhancements. In order toprevent this article becoming too large some of these features have been split off into separate

articles, but the following sections represent an explanation of the all the new features listed intheWhat's New in PL/SQL?section of the PL/SQL Language Reference manual.

Topics covered in this article:

Enhancements to Regular Expression Built-in SQL Functions SIMPLE_INTEGER Datatype CONTINUE Statement Sequences in PL/SQL Expressions

Dynamic SQL Enhancements Generalized Invocation Named and Mixed Notation in PL/SQL Subprogram Invocations Automatic Subprogram Inlining PL/Scope PL/SQL Native Compiler Generates Native Code Directly New PL/SQL Compiler Warning PLS-00436 Restriction in FORALL Statements Removed

Topics covered in separate articles on this site:

Cross-Session PL/SQL Function Result Cache

Trigger Enhancements in Oracle Database 11g Release 1 PL/SQL Hierarchical Profiler Native Oracle XML DB Web Services Database Resident Connection Pool

Enhancements to Regular Expression Built-in SQL

Functions

TheREGEXP_INSTRandREGEXP_SUBSTRfunctions include a new SUBEXPR parameter that

limits the pattern match to a specific subexpression in the search pattern.SQL> SELECT REGEXP_INSTR('1234567890', '(123)(4(56)(78))', 1, 1, 0, 'i', 1)FROM dual;

REGEXP_INSTR('1234567890','(123)(4(56)(78))',1,1,0,'I',1)---------------------------------------------------------

1

1 row selected.
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SQL> SELECT REGEXP_INSTR('1234567890', '(123)(4(56)(78))', 1, 1, 0, 'i', 3)FROM dual;

REGEXP_INSTR('1234567890','(123)(4(56)(78))',1,1,0,'I',3)---------------------------------------------------------

5

1 row selected.

SQL> SELECT REGEXP_SUBSTR('1234567890', '(123)(4(56)(78))', 1, 1, 'i', 0)FROM dual;

REGEXP_S--------12345678

1 row selected.


REG---123

1 row selected.


RE--56

1 row selected.

SQL>

The newREGEXP_COUNTfunction returns the number of times the search pattern appears in

source string.SQL> SELECT REGEXP_COUNT('123 123 123 123', '123', 1, 'i') FROM dual;

REGEXP_COUNT('123123123123','123',1,'I')----------------------------------------

4

1 row selected.

SQL> SELECT REGEXP_COUNT('123 123 123 123', '123', 9, 'i') FROM dual;

REGEXP_COUNT('123123123123','123',9,'I')----------------------------------------

2

1 row selected.

SQL>
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SIMPLE_INTEGER Datatype

The SIMPLE_INTEGER datatype is a subtype of the PLS_INTEGER datatype and can dramatically

increase the speed of integer arithmetic in natively compiled code, but only shows marginalperformance improvements in interpreted code. The following procedure compares the

performance of the SIMPLE_INTEGER and PLS_INTEGER datatypes.CREATE OR REPLACE PROCEDURE simple_integer_test_proc AS

l_start NUMBER;l_loops NUMBER := 10000000;l_pls_integer PLS_INTEGER := 0;l_pls_integer_incr PLS_INTEGER := 1;l_simple_integer SIMPLE_INTEGER := 0;l_simple_integer_incr SIMPLE_INTEGER := 1;

BEGIN

l_start := DBMS_UTILITY.get_time;

FOR i IN 1 .. l_loops LOOP

l_pls_integer := l_pls_integer + l_pls_integer_incr;END LOOP;

DBMS_OUTPUT.put_line('PLS_INTEGER: ' || (DBMS_UTILITY.get_time - l_start)|| ' hsecs');


FOR i IN 1 .. l_loops LOOPl_simple_integer := l_simple_integer + l_simple_integer_incr;

END LOOP;

DBMS_OUTPUT.put_line('SIMPLE_INTEGER: ' || (DBMS_UTILITY.get_time -l_start) || ' hsecs');

END simple_integer_test_proc;/

When run in the default interpreted mode the performance improvement of the SIMPLE_INTEGERdatatype is not spectacular.SQL> SET SERVEROUTPUT ONSQL> EXEC simple_integer_test_proc;PLS_INTEGER: 47 hsecsSIMPLE_INTEGER: 44 hsecs

PL/SQL procedure successfully completed.

SQL>

We natively compile the procedure by altering the PLSQL_CODE_TYPE value for the session andrecompiling the procedure.ALTER SESSION SET PLSQL_CODE_TYPE=NATIVE;ALTER PROCEDURE simple_integer_test_proc COMPILE;

Natively compiling the procedure produces dramatic speed improvements for both datatypes, but

more so for the SIMPLE_INTEGER datatype.SQL> SET SERVEROUTPUT ON


4/19

SQL> EXEC simple_integer_test_proc;PLS_INTEGER: 10 hsecsSIMPLE_INTEGER: 2 hsecs


SQL>

The speed improvements are a result of two fundamental differences between the two datatypes.

First, SIMPLE_INTEGER and PLS_INTEGER have the same range (-2,147,483,648 through

2,147,483,647), but SIMPLE_INTEGER wraps round when it exceeds its bounds, rather than

throwing an error like PLS_INTEGER.SET SERVEROUTPUT ONDECLARE

l_simple_integer SIMPLE_INTEGER := 2147483645;BEGIN

FOR i IN 1 .. 4 LOOPl_simple_integer := l_simple_integer + 1;DBMS_OUTPUT.PUT_LINE(TO_CHAR(l_simple_integer, 'S9999999999'));

END LOOP;

FOR i IN 1 .. 4 LOOPl_simple_integer := l_simple_integer - 1;DBMS_OUTPUT.PUT_LINE(TO_CHAR(l_simple_integer, 'S9999999999'));

END LOOP;END;/+2147483646+2147483647-2147483648-2147483647-2147483648+2147483647+2147483646+2147483645


SQL>

Second, SIMPLE_INTEGER can never have a NULL value, either when it is declared, or byassignment.DECLARE

l_simple_integer SIMPLE_INTEGER;BEGIN

NULL;END;/

*ERROR at line 2:ORA-06550: line 2, column 20:PLS-00218: a variable declared NOT NULL must have an initializationassignment

SQL>

DECLARE


5/19

l_simple_integer SIMPLE_INTEGER := 0;BEGIN

l_simple_integer := NULL;END;/

*ERROR at line 4:ORA-06550: line 4, column 23:PLS-00382: expression is of wrong typeORA-06550: line 4, column 3:PL/SQL: Statement ignored

SQL>

The removal of overflow and NULL checking result in a significant reduction in overhead

compared to PLS_INTEGER.

CONTINUE Statement

The CONTINUE statement jumps out of the current loop interation and starts the next one. It can beused on its own, or as part of a CONTINUE WHEN statement, as shown below.SET SERVEROUTPUT ONDECLARE

l_number NUMBER := 0;BEGIN

FOR i IN 1 .. 100 LOOPCONTINUE WHEN MOD(i,2) = 0;

-- Do something here!l_number := l_number + 1;

END LOOP;

DBMS_OUTPUT.put_line('CONTINUE WHEN : ' || l_number);

l_number := 0;

FOR i IN 1 .. 100 LOOPIF MOD(i,2) = 0 THEN

CONTINUE;END IF;


END LOOP;

DBMS_OUTPUT.put_line('IF .. CONTINUE: ' || l_number);

END;/CONTINUE WHEN : 50IF .. CONTINUE: 50


SQL>


6/19

This type of processing has always been possible using IF statements either on their own or with

exceptions or GOTO statements, but the CONTINUE statement is neater and brings PL/SQL in line

with other langauges. The following examples show the type of code necessary to perform the

same task before the CONTINUE statement was added to PL/SQL.SET SERVEROUTPUT ONDECLARE

ex_continue EXCEPTION;l_number NUMBER := 0;

BEGINFOR i IN 1 .. 100 LOOPBEGIN

IF MOD(i,2) != 0 THENRAISE ex_continue;

END IF;


EXCEPTIONWHEN ex_continue THEN

NULL;END;

END LOOP;

DBMS_OUTPUT.put_line('EXCEPTION: ' || l_number);

l_number := 0;

FOR i IN 1 .. 100 LOOPIF MOD(i,2) != 0 THEN


END IF;END LOOP;

DBMS_OUTPUT.put_line('IF : ' || l_number);

l_number := 0;

FOR i IN 1 .. 100 LOOPIF MOD(i,2) = 0 THEN

GOTO label_continue;END IF;

-- Do something here!

l_number := l_number + 1;

>NULL;

END LOOP;

DBMS_OUTPUT.put_line('GOTO : ' || l_number);END;/EXCEPTION: 50


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IF : 50GOTO : 50


SQL>

Sequences in PL/SQL Expressions

The NEXTVAL and CURRVAL sequence pseudocolumns can now be accessed in PL/SQL

expressions as well as queries. This makes the code look simpler, and the documentationsuggests it improves performance. The following example compares the speed of the original and

new methods of accessing these sequence values.CREATE SEQUENCE test1_seq START WITH 1000000;

SET SERVEROUTPUT ONDECLARE

l_start NUMBER;

l_loops NUMBER := 100000;l_value NUMBER;

BEGIN


FOR i IN 1 .. l_loops LOOPSELECT test1_seq.NEXTVALINTO l_valueFROM dual;

END LOOP;

DBMS_OUTPUT.put_line('NEXTVAL SELECT=' || (DBMS_UTILITY.get_time - l_start)

|| ' hsecs');


FOR i IN 1 .. l_loops LOOPl_value := test1_seq.NEXTVAL;

END LOOP;

DBMS_OUTPUT.put_line('NEXTVAL Expression=' || (DBMS_UTILITY.get_time -l_start) || ' hsecs');


FOR i IN 1 .. l_loops LOOP

SELECT test1_seq.CURRVALINTO l_valueFROM dual;

END LOOP;

DBMS_OUTPUT.put_line('CURRVAL SELECT=' || (DBMS_UTILITY.get_time - l_start)|| ' hsecs');



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FOR i IN 1 .. l_loops LOOPl_value := test1_seq.CURRVAL;

END LOOP;

DBMS_OUTPUT.put_line('CURRVAL Expression=' || (DBMS_UTILITY.get_time -l_start) || ' hsecs');

END;/NEXTVAL SELECT=2196 hsecsNEXTVAL Expression=2203 hsecsCURRVAL SELECT=1007 hsecsCURRVAL Expression=1003 hsecs


SQL>

You can see that as far as elapsed time is concerned, there is little difference between the twomethods.

Dynamic SQL Enhancements

Native dynamic SQL and the DBMS_SQL package now support dynamic SQL statements largerthan 32 KB. TheEXECUTE IMMEDIATEstatement,OPEN-FORstatement and

DBMS_SQL.PARSEprocedure all accept SQL statements in the form of CLOBs.

TheDBMS_SQL.TO_REFCURSORfunction converts a DBMS_SQL cursor ID into a REFCURSOR.

SET SERVEROUTPUT ONDECLAREl_cursor NUMBER;l_return NUMBER;

l_ref_cursor SYS_REFCURSOR;TYPE t_emp_tab IS TABLE OF emp%ROWTYPE;l_emp_tab t_emp_tab;

BEGINl_cursor := DBMS_SQL.open_cursor;

DBMS_SQL.parse(l_cursor, 'SELECT * FROM emp', DBMS_SQL.NATIVE);

l_return := DBMS_SQL.EXECUTE(l_cursor);

-- Connvert from DBMS_SQL to a REF CURSOR.l_ref_cursor := DBMS_SQL.to_refcursor(l_cursor);FETCH l_ref_cursor BULK COLLECT INTO l_emp_tab;

DBMS_OUTPUT.put_line('Employee Count: ' || l_emp_tab.count);

CLOSE l_ref_cursor;END;
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9/19

/Employee Count: 14


SQL>

TheDBMS_SQL.TO_CURSOR_NUMBERfunction converts a REF CURSOR into aDBMS_SQL cursor ID.SET SERVEROUTPUT ONDECLARE

l_ref_cursor SYS_REFCURSOR;

l_cursor NUMBER;l_count NUMBER := 0;

BEGINOPEN l_ref_cursor FOR 'SELECT * FROM emp';

l_cursor := DBMS_SQL.to_cursor_number(l_ref_cursor);

WHILE DBMS_SQL.fetch_rows(l_cursor) > 0 LOOPl_count := l_count + 1;

END LOOP;

DBMS_OUTPUT.put_line('Employee Count: ' || l_count);

DBMS_SQL.close_cursor(l_cursor);END;/Employee Count: 14


SQL>

In addition, the DBMS_SQL package now supports all datatypes supported by native dynamicSQL.

Generalized Invocation

Generalized invocation allows a subtype to invoke a method of a parent type (supertype) using

the following syntax.(SELF AS supertype_name).method_name

The following example shows this in action.

First, we create a type with some attributes and a member function.CREATE OR REPLACE TYPE my_type AS OBJECT (

id NUMBER,description VARCHAR2(50),MEMBER FUNCTION show_attributes RETURN VARCHAR2)NOT FINAL;

/

CREATE OR REPLACE TYPE BODY my_type AS
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MEMBER FUNCTION show_attributes RETURN VARCHAR2 ISBEGINRETURN 'id=' || id || ' description=' || description;

END;

END;/

Next, we create a subtype of this object, which adds a new attribute and method as well as

overriding the show_attributes member function.CREATE OR REPLACE TYPE my_subtype UNDER my_type (

short_desc VARCHAR2(10),OVERRIDING MEMBER FUNCTION show_attributes RETURN VARCHAR2,MEMBER FUNCTION show_parent_attributes RETURN VARCHAR2);

/

CREATE OR REPLACE TYPE BODY my_subtype AS

OVERRIDING MEMBER FUNCTION show_attributes RETURN VARCHAR2 ISBEGINRETURN (self AS my_type).show_attributes || ' short_desc=' ||

short_desc;END;

MEMBER FUNCTION show_parent_attributes RETURN VARCHAR2 ISBEGINRETURN (self AS my_type).show_attributes;

END;

END;/

Notice the method of the parent type is accessed using the generalized invocation syntax. Thecode below creates a subtype and invokes its member functions.SET SERVEROUTPUT ONDECLARE

l_subtype my_subtype := my_subtype(1, 'Long description for 1', 'S Desc1');BEGIN

DBMS_OUTPUT.put_line('show_attributes=' || l_subtype.show_attributes);DBMS_OUTPUT.put_line('show_parent_attributes=' ||

l_subtype.show_parent_attributes);END;/show_attributes=id=1 description=Long description for 1 short_desc=S Desc 1show_parent_attributes=id=1 description=Long description for 1


SQL>

A type can invoke the member functions of any parent type in this way, regardless of the depthof the inheritance.


11/19

Named and Mixed Notation in PL/SQL Subprogram

Invocations

Prior to 11g, PL/SQL invoked from SQL had to have its parameters passed using positional

notation, making it difficult to determine the meaning of parameters. Oracle 11g allowspositional, named and mixed notation to be used when calling PL/SQL from SQL, as shown

below.-- Build a test function with multiple parameters.CREATE OR REPLACE FUNCTION test_func(p_value_1 IN NUMBER DEFAULT 0,

p_value_2 IN NUMBER DEFAULT 0)RETURN NUMBER AS

BEGINRETURN p_value_1 + p_value_2;

END test_func;/

Function created.

SQL> -- Positional Notation.SQL> SELECT test_func(10, 20) FROM dual;

TEST_FUNC(10,20)----------------

30

1 row selected.

SQL> -- Mixed Notation.SQL> SELECT test_func(10, p_value_2 => 20) FROM dual;

TEST_FUNC(10,P_VALUE_2=>20)

---------------------------30

1 row selected.

SQL> -- Named Notation.SQL> SELECT test_func(p_value_1 => 10, p_value_2 => 20) FROM dual;

TEST_FUNC(P_VALUE_1=>10,P_VALUE_2=>20)--------------------------------------

30

1 row selected.

SQL>

Automatic Subprogram Inlining

Every call to a procedure or function causes a slight, but measurable, performance overhead,

which is especially noticeable when the subprogram is called within a loop. Avoiding proceduresand functions is not an option, as it goes against the concept of modular programming, making


12/19

programs bulky and difficult to manage. Automatic subprogram inlining can reduce the

overheads associated with calling subprograms, whilst leaving your original source code in itsnormal modular state. This is done by replacing the subprogram calls with a copy of the code in

the subprogram at compile time.

The process of subprogram inlining is controlled by the PLSQL_OPTIMIZE_LEVEL parameter andthe INLINE pragma. When PLSQL_OPTIMIZE_LEVEL=2 (the default), the INLINE pragma

determines whether the following statement or declaration should be inlined or not. When

PLSQL_OPTIMIZE_LEVEL=3, the optimizer may inline code automatically. In this case the INLINEpragma can turn it off inlining for a statement, or increase the likelihood that the optimizer will

choose to inline a statement. The relationship is easier to understand when you see the followingexample.

These tests use an anonymous block with a function defined in the declaration block. The

function is then called repeatedly in a loop. The settings for PLSQL_OPTIMIZE_LEVEL and the

INLINE pragma are altered to switch subprogram inlining on and off. First, we make sure

PLSQL_OPTIMIZE_LEVEL=2 and run the code with no INLINE pragma set. With these settings wewould not expect to see subprogram inlining taking place.ALTER SESSION SET PLSQL_OPTIMIZE_LEVEL=2;


l_loops NUMBER := 10000000;l_start NUMBER;l_return NUMBER;

FUNCTION add_numbers (p_1 IN NUMBER,p_2 IN NUMBER)

RETURN NUMBER AS

BEGINRETURN p_1 + p_2;END add_numbers;

BEGINl_start := DBMS_UTILITY.get_time;

FOR i IN 1 .. l_loops LOOP--PRAGMA INLINE (add_numbers, 'YES');l_return := add_numbers(1, i);

END LOOP;

DBMS_OUTPUT.put_line('Elapsed Time: ' || (DBMS_UTILITY.get_time - l_start)|| ' hsecs');

END;/Elapsed Time: 509 hsecs


SQL>

This results in an elapsed time of 509 hsecs.


13/19

Next, we keep the same optimization setting, but include the INLINE pragma with a setting of

"YES" for the calls to the ADD_NUMBERS function. We would now expect subprogram inlining to

take place.ALTER SESSION SET PLSQL_OPTIMIZE_LEVEL=2;

SET SERVEROUTPUT ON

DECLAREl_loops NUMBER := 10000000;l_start NUMBER;l_return NUMBER;


RETURN NUMBER ASBEGINRETURN p_1 + p_2;

END add_numbers;

BEGIN


FOR i IN 1 .. l_loops LOOPPRAGMA INLINE (add_numbers, 'YES');l_return := add_numbers(1, i);

END LOOP;

DBMS_OUTPUT.put_line('Elapsed Time: ' || (DBMS_UTILITY.get_time - l_start)|| ' hsecs');END;/Elapsed Time: 245 hsecs


SQL>

This gives an elapsed time of 245 hsec, which is approximately half that of the previous test,

implying that subprogram inlining is taking place.

Next, we make sure PLSQL_OPTIMIZE_LEVEL=3 and run the code with no INLINE pragma set.

We would now expect the optimizer to implicitly choose to inline the ADD_NUMBERS call.ALTER SESSION SET PLSQL_OPTIMIZE_LEVEL=3;


l_loops NUMBER := 10000000;

l_start NUMBER;l_return NUMBER;



END add_numbers;


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FOR i IN 1 .. l_loops LOOP--PRAGMA INLINE (add_numbers, 'YES');l_return := add_numbers(1, i);

END LOOP;

DBMS_OUTPUT.put_line('Elapsed Time: ' || (DBMS_UTILITY.get_time - l_start)|| ' hsecs');END;/Elapsed Time: 245 hsecs


SQL>

This gives an elapsed time of 245 hsec, which implies that subprogram inlining is still takingplace.

Finally, we make sure PLSQL_OPTIMIZE_LEVEL=3 and run the code with an INLINE pragma set

to "NO". We would expect there to be no inlining of the ADD_NUMBERS call now.ALTER SESSION SET PLSQL_OPTIMIZE_LEVEL=3;


l_loops NUMBER := 10000000;l_start NUMBER;l_return NUMBER;



END add_numbers;


FOR i IN 1 .. l_loops LOOPPRAGMA INLINE (add_numbers, 'NO');l_return := add_numbers(1, i);

END LOOP;

DBMS_OUTPUT.put_line('Elapsed Time: ' || (DBMS_UTILITY.get_time - l_start)

|| ' hsecs');END;/Elapsed Time: 500 hsecs


SQL>


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This gives an elapsed time of 500 hsecs, which implies that inlining did not take place as we

expected.

The INLINE pragma only affects the following types of statements.

Assignment

Call Conditional CASE CONTINUE-WHEN EXECUTE IMMEDIATE EXIT-WHEN LOOP RETURN

In each case, it affects every call to specified subprogram from the statement.

The optimizer can choose to ignore an INLINE pragma setting of "YES" if it believes inlining is

undesirable, but a setting of "NO" will always prevent inlining.

The compiler inlines subprograms early in the optimization process, which may preventing later,

more powerful optimizations taking place. As a result, performance almost always improves with

inlining, but in some cases it may not be effective.

PL/Scope

PL/Scope is a tool that gathers information about user defined identifiers at compile time.Collection of PL/Scope data is controlled by the PLSCOPE_SETTINGS parameter, which has a

default setting of "IDENTIFIERS:NONE". Switch this value to "IDENTIFIERS:ALL" to enablecollection.SQL> ALTER SESSION SET PLSCOPE_SETTINGS='IDENTIFIERS:ALL';

Session altered.

SQL>

Data collection is performed for all objects compiled after the flag is set, so we must now createan object to gather some data.CREATE OR REPLACE PROCEDURE test_plscope (p_in IN NUMBER) AS

l_var NUMBER;BEGINl_var := p_in;

l_var := l_var + 1;END;/

The data is stored in the SYSAUX tablespace, so the current space used for PL/Scope data canbe displayed with the following query.SELECT space_usage_kbytes


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FROM v$sysaux_occupantsWHERE occupant_name = 'PL/SCOPE';

SPACE_USAGE_KBYTES------------------

384

1 row selected.

SQL>

The PL/Scope data is available from the%_IDENTIFIERSviews. The following query displays

data gathered during the compilation of the test_plscope procedure.COLUMN name FORMAT A30SELECT LPAD(' ', level*2, ' ') || name AS name, type, usage, usage_id, line,colFROM user_identifiersSTART WITH usage_context_id = 0CONNECT BY PRIOR usage_id = usage_context_id;

NAME TYPE USAGE USAGE_IDLINE COL------------------------------ ------------------ ----------- ---------- ---------- ----------

TEST_PLSCOPE PROCEDURE DECLARATION 11 11

TEST_PLSCOPE PROCEDURE DEFINITION 21 11

P_IN FORMAL IN DECLARATION 31 25

L_VAR VARIABLE DECLARATION 42 3

L_VAR VARIABLE ASSIGNMENT 54 3

P_IN FORMAL IN REFERENCE 64 12

L_VAR VARIABLE ASSIGNMENT 76 3

L_VAR VARIABLE REFERENCE 86 12

8 rows selected.

SQL>

The likelihood is that most users will view the PL/Scope data via a PL/SQL IDE, such as SQLDeveloper.

The documentation states that some identifiers will not listed unless the STANDARD package isrecompiled after the PLSCOPE_SETTINGS parameter is set as follows. This results in over 7,000invalid objects, most of which will not recompile even when using the urlrp.sql script. I don't

recommend this approach if you want a working instance.

PL/SQL Native Compiler Generates Native Code Directly
http://download.oracle.com/docs/cd/B28359_01/server.111/b28320/statviews_1089.htm#REFRN20599http://download.oracle.com/docs/cd/B28359_01/server.111/b28320/statviews_1089.htm#REFRN20599http://download.oracle.com/docs/cd/B28359_01/server.111/b28320/statviews_1089.htm#REFRN20599http://download.oracle.com/docs/cd/B28359_01/server.111/b28320/statviews_1089.htm#REFRN20599


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Native compilation of PL/SQL code as been possible since Oracle 9i. See:

PL/SQL Native Compilation (9i) PL/SQL Native Compilation Enhancements (10g)

In these versions of the database, the PL/SQL code was converted to C code, compiled and runas external procedures. Using natively compiled PL/SQL needed a C compiler on the server andintervention from the DBA. In addition, using natively compiled PL/SQL in a RAC environment

could prove problematic.

In Oracle 11g, PL/SQL native compilation requires no C compiler, no DBA intervention and is

fully supported in a RAC environment. By setting the PLSQL_CODE_TYPE to a value ofNATIVE,

rather than the default value ofINTERPRETED, code is compiled directly to machine code andstored in the SYSTEM tablespace. When the code is called, it is loaded into shared memory,

making it accessible for all sessions in that instance. The %_PLSQL_OBJECT_SETTINGS views

include the current PLSQL_CODE_TYPE setting for each PL/SQL object.

Remember, native compilation will improve the speed of procedure code, but has no effect on

the performance of SQL. When code performs lots of mathematical operations, like theSIMPLE_INTEGERexample, native compilation can produce considerable performance

improvements. If code is predominantly performing SQL, little improvement will be noticed.

As with previous database versions, it is possible to natively compile all PL/SQL code in thedatabase, provided you follow thesupported procedure.

New PL/SQL Compiler Warning

A new PL/SQL compiler warning has been added to identify WHEN OTHERS exception handlers

that do no re-raise errors using RAISE or RAISE_APPLICATION_ERROR. Such exception handlerscan often hide code failures that result in hard to identify bugs. The example below shows the

expected compiler warning when the PLSQL_WARNINGS flag is set.SQL> ALTER SESSION SET plsql_warnings = 'enable:all';

Session altered.

SQL> CREATE OR REPLACE PROCEDURE others_test AS2 BEGIN3 RAISE_APPLICATION_ERROR(-20000, 'Force and exception');

4 EXCEPTION5 WHEN OTHERS THEN6 NULL;7 END;8 /

SP2-0804: Procedure created with compilation warnings

SQL> SHOW ERRORSErrors for PROCEDURE OTHERS_TEST:
http://www.oracle-base.com/articles/9i/PLSQLNativeCompilation9i.phphttp://www.oracle-base.com/articles/9i/PLSQLNativeCompilation9i.phphttp://www.oracle-base.com/articles/10g/PlsqlEnhancements10g.php#plsql_native_compilationhttp://www.oracle-base.com/articles/10g/PlsqlEnhancements10g.php#plsql_native_compilationhttp://www.oracle-base.com/articles/11g/PlsqlNewFeaturesAndEnhancements_11gR1.php#simple_integerhttp://www.oracle-base.com/articles/11g/PlsqlNewFeaturesAndEnhancements_11gR1.php#simple_integerhttp://download.oracle.com/docs/cd/B28359_01/appdev.111/b28370/tuning.htm#BABEJGDIhttp://download.oracle.com/docs/cd/B28359_01/appdev.111/b28370/tuning.htm#BABEJGDIhttp://download.oracle.com/docs/cd/B28359_01/appdev.111/b28370/tuning.htm#BABEJGDIhttp://download.oracle.com/docs/cd/B28359_01/appdev.111/b28370/tuning.htm#BABEJGDIhttp://www.oracle-base.com/articles/11g/PlsqlNewFeaturesAndEnhancements_11gR1.php#simple_integerhttp://www.oracle-base.com/articles/10g/PlsqlEnhancements10g.php#plsql_native_compilationhttp://www.oracle-base.com/articles/9i/PLSQLNativeCompilation9i.php


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LINE/COL ERROR-------- -----------------------------------------------------------------5/8 PLW-06009: procedure "OTHERS_TEST" OTHERS handler does not end in

RAISE or RAISE_APPLICATION_ERROR

SQL>

This is only a warning message, so it only identifies possible problem code, it doesn't prevent it.

PLS-00436 Restriction in FORALL Statements Removed

The PLS-00436 restriction has been removed, which means you can now reference the individual

elements of a collection within the SET and WHERE clauses of a DML statement in a FORALLconstruct. To see this in action, create and populates a test table using the following code.CREATE TABLE forall_test (

id NUMBER,description VARCHAR2(50)

);

INSERT INTO forall_test VALUES (1, 'ONE');INSERT INTO forall_test VALUES (2, 'TWO');INSERT INTO forall_test VALUES (3, 'THREE');INSERT INTO forall_test VALUES (4, 'FOUR');INSERT INTO forall_test VALUES (5, 'FIVE');COMMIT;

The PL/SQL block below populates a collection with the existing data, amends the data in thecollection, then updates the table with the amended data. The final query displays the changed

data in the table.DECLARE

TYPE t_forall_test_tab IS TABLE OF forall_test%ROWTYPE;l_tab t_forall_test_tab;

BEGIN-- Retrieve the existing data into a collection.SELECT *BULK COLLECT INTO l_tabFROM forall_test;

-- Alter the data in the collection.FOR i IN l_tab.first .. l_tab.last LOOPl_tab(i).description := 'Description for ' || i;

END LOOP;

-- Update the table using the collection.

FORALL i IN l_tab.first .. l_tab.lastUPDATE forall_testSET description = l_tab(i).descriptionWHERE id = l_tab(i).id;

COMMIT;END;/

SELECT * FROM forall_test;


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ID DESCRIPTION

---------- ---------------------------1 Description for 12 Description for 23 Description for 34 Description for 45 Description for 5

5 rows selected.

SQL>

Notice both the SET and WHERE clauses contain references to individual columns in the collection.This makes using bulk-binds for DML even easier as we no longer need to maintain multiple

collections if we need to reference columns in the WHERE clause. It can also improve performance

of updates, as previous versions required updates of the whole row using the ROW keyword,which included potentially unnecessary updates of primary key and foreign key columns.

For more information see:

What's New in PL/SQL? - Oracle Database PL/SQL Language Reference 11g Release 1(11.1)

Oracle Database PL/SQL Packages and Types Reference 11g Release 1 (11.1)
http://download.oracle.com/docs/cd/B28359_01/appdev.111/b28370/whatsnew.htm#CJAEGHHHhttp://download.oracle.com/docs/cd/B28359_01/appdev.111/b28370/whatsnew.htm#CJAEGHHHhttp://download.oracle.com/docs/cd/B28359_01/appdev.111/b28370/whatsnew.htm#CJAEGHHHhttp://download.oracle.com/docs/cd/B28359_01/appdev.111/b28370/whatsnew.htm#CJAEGHHHhttp://download.oracle.com/docs/cd/B28359_01/appdev.111/b28370/whatsnew.htm#CJAEGHHHhttp://download.oracle.com/docs/cd/B28359_01/appdev.111/b28419/toc.htmhttp://download.oracle.com/docs/cd/B28359_01/appdev.111/b28419/toc.htmhttp://download.oracle.com/docs/cd/B28359_01/appdev.111/b28419/toc.htmhttp://download.oracle.com/docs/cd/B28359_01/appdev.111/b28370/whatsnew.htm#CJAEGHHHhttp://download.oracle.com/docs/cd/B28359_01/appdev.111/b28370/whatsnew.htm#CJAEGHHH

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