tune my code! code-versionen testen via edition-based redef. - jérôme witt, dbi services

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Edition Based Redefinition

www.dbi-services.com 1 08.11.2012

Jérôme Witt

Consultant - Oracle Certified Professional 11g

Mobile +41 79 961 27 73

[email protected]

www.dbi-services.com

mailto:[email protected]



http://www.dbi-services.com/




Agenda Agenda


Agenda

i. Introduction

ii. Concept

iii. Basics

iv. Redefining objects

v. Advanced functionalities

vi. Limits



Upgrading applications can be difficult

Short or long downtimes can not be scheduled

Implementation of online upgrades are desirable

As of Oracle Database 11gR2 with Oracle Edition Based Redefinition (aka. EBR) online application upgrades are now supported

Announced as “the killer feature” at the OOW 2009


Introduction



• Creation of new objects

• Changing objects (alter and create or replace)

• Drop redundant objects

• Convert or migrate data

• Resume normal operations


Introduction


Ap

pli

cati

on

up

grad

e

Downtime

EBR


Agenda Agenda


Agenda

i. Introduction

ii. Concept

iii. Basics



vi. Limits



As of Oracle 11gR2 an object is identified by

His name and the schema it belongs to

And now also to an EDITION

Allows to support several copies of an object

Objects which might have copies are called “editioned objects”

All other objects are “non editionable”


Concept(1)


SQL> desc DBA_OBJECTS

Name Null? Type

------------------ -------- ----------------

. . .

EDITION_NAME VARCHAR2(30)


Which objects are “editionable” ?

A non-editonable object cannot depend on an editonable object


Concept (2)


SYNONYM VIEW

All PL/SQL objects PACKAGE and PACKAGE BODY PROCEDURE FUNCTION LIBRARY TRIGGER TYPE and TYPE BODY


Editions are organized hierarchically


Concept(3)


«parent-child»

ORA$BASE

ED1

• OBJ_1 • OBJ_2 • OBJ_3

ED2

• OBJ_2

ED3

• OBJ_1

• OBJ_3

ED2


Editions are organized hierarchically

Inheritance

When an edition is created all objects associated with the parent are inherited by the child. They become «inherited»

Objects re-created or altered in an edition become “actualized” (i.e. objects OBJ_2 & OBJ_3 of the edition ED3)

Inherited & actual objects are “visible”


Concept(4)


«parent-child»

ORA$BASE

ED1

• OBJ_1 • OBJ_2 • OBJ_3

ED2

• OBJ_2

ED3

• OBJ_1

• OBJ_3


Agenda Agenda


Agenda

i. Introduction

ii. Concept

iii. Basics



vi. Limits



Creating editions

Database default edition «ORA$BASE»

Database creation or upgrade to Oracle 11.2

Has no actual editioned objects

Enabling editions

Editioned objects can only be owned by schemas that have been explicitly enabled

FORCE if schema has potentially editionable objects

By the way DISABLE EDTIONS doesn’t exists !


Basics (1)


SQL> ALTER USER <schema> ENABLE EDITIONS {FORCE};

SQL> CREATE EDITION <ed_name> {AS CHILD OF ora$base};


Granting editions

Selecting editions

Retrieving current and session edition


Basics (2)


SQL> GRANT USE ON EDITION <ed_name> TO <schema>;

SQL> ALTER SESSION SET EDITION =<ed_name>;

SQL> SHOW EDITION;

SQL> SELECT

SYS_CONTEXT('USERENV', 'CURRENT_EDITION_NAME'),

SYS_CONTEXT('USERENV', 'SESSION_EDITION_NAME')

FROM dual;


Enabling an edition database wide

Selecting edition at connection time

EBR integrated with

Oracle Call Interface

Oracle Restart (srvctl)


Basics (3)


SQL> ALTER DATABASE DEFAULT EDITION=<ed_name>;

SQL> SELECT property_value FROM database_properties

WHERE property_name = 'DEFAULT_EDITION';

DBMS_SERVICE.CREATE_SERVICE(

service_name => '<ORACLE_SID.DB_DOMAIN>',

. . .

edition => '<ed_name>');

JDBC


Display all database editions

Views {DBA|ALL}_EDITIONS

Display all objects editions

Views {DBA|ALL|USER}_OBJECTS_AE

View current edition from an object

Views {DBA|ALL|USER}_OBJECTS.EDITION_NAME

And so on …


Basics (4)



Agenda Agenda


Agenda

i. Introduction

ii. Concept

iii. Basics



vi. Limits




Redefining objects(1)


SQL> BEGIN

raiseSalary(

p_title_in => 'COM_DBISERVICES . . . ',

p_rate_in => 1.10,

p_max_sal_in => 50000 );

END;

/





PROCEDURE raiseSalary(. . .) IS

. . .

CURSOR cur_emp IS SELECT * FROM EMPLOYEES FOR UPDATE;

BEGIN

OPEN cur_emp;

LOOP

FETCH cur_emp INTO rec_emp;

. . .

SELECT upper(job_title) INTO v_cur_title FROM hr.jobs

WHERE job_id = rec_emp.job_id;

IF v_cur_title = v_title_in

AND rec_emp.salary*p_rate_in <= p_max_sal_in

THEN

-- Do some other checks on employee

UPDATE . . .

END IF;

END LOOP;

CLOSE cur_emp;

COMMIT;

END;





PROCEDURE raiseSalary(. . .) IS

. . .

CURSOR cur_emp IS

SELECT e.employee_id from hr.employees e, hr.jobs j

WHERE e.job_id = j.job_id AND upper(j.job_title) = v_title_in

AND e.salary*p_rate_in <= p_max_sal_in;

BEGIN

OPEN cur_emp;

LOOP

FETCH cur_emp BULK COLLECT INTO v_empid_list LIMIT 1000;

EXIT WHEN v_empid_list.COUNT = 0;

-- Do some other checks on employee

FORALL i IN v_empid_list.FIRST .. v_empid_list.LAST

UPDATE hr.employees SET salary=salary*p_rate_in

WHERE employee_id=v_empid_list(i);

END LOOP;

CLOSE cur_emp; COMMIT;

END;


Typical EBR redefinition steps

1. Create the new edition

2. Set the edition as session edition

3. Redefine the objects

4. Permanently switch to the new edition

To “redefine” objects it’s necessary to select the new edition and either re-compile or recreate objects

Consider application roll out strategy





Agenda Agenda


Agenda

i. Introduction

ii. Concept

iii. Basics



vi. Limits



Views

Editionable (of course)

Support only INSTEAD OF triggers

Editioning views

Selects a subset of the columns from a single base table

Optionally, provide aliases for columns

Doesn’t support indexes nor constraints

No performance penalty for accessing base table

Support any type of triggers (especially CROSSEDITION TRIGGERS)


Advanced functionalities(1)


SQL> CREATE EDITIONING VIEW <name> AS SELECT ...;


Crossedition triggers

Propagate data changes made by the old edition into the new edition’s columns, or vice-versa.

From type FORWARD or REVERSE

They are temporary!




SQL> CREATE OR REPLACE TRIGGER <trigger_name>

BEFORE INSERT OR UPDATE ON <table_name>

FOR EACH ROW

FORWARD CROSSEDITION

DISABLE

BEGIN

. . .

END <trigger_name>;

/





C_Pool ED_V1

EMPLOYEES_TAB

First Name

Last Name

Phone Nbr

EMPLOYEES

First Name

Last Name

Phone Nbr

EMPLOYEES

First Name

Last Name

Phone Nbr

New Edition : ED_V1


EMPLOYEES

First Name

Last Name

Phone Nbr




C_Pool ED_V1

New Edition : ED_V1 New Edition : ED_V2

FWD_TRG

REV_TRG

EMPLOYEES_TAB

First Name

Last Name

Phone Nbr

EMPLOYEES_TAB

First Name

Last Name

Phone Nbr

Dial Code

Int PhNbr

EMPLOYEES

First Name

Last Name

Phone Nbr

Dial Code

Int PhNbr





C_Pool ED_V1

EMPLOYEES_TAB

First Name

Last Name

Phone Nbr

Dial Code

Int PhNbr

EMPLOYEES

First Name

Last Name

Phone Nbr

Dial Code

Int PhNbr

C_Pool ED_V2

FWD_TRG

REV_TRG

New Edition : ED_V2


Hot roll-over “bulk forward”

Wait for pending DMLs

Apply transformation




DBMS_UTILITY.WAIT_ON_PENDING_DML(

tables => '<Base_Table>',

timeout => timeout,

scn => scn

);

DBMS_SQL.PARSE(

c => c,

Language_Flag => DBMS_SQL.NATIVE,

Statement=> 'UPDATE employees SET ID = ID',

Apply_Crossedition_Trigger => '<CRED_TRG_FWD>'

);


Agenda Agenda


Agenda

i. Introduction

ii. Concept

iii. Basics



vi. Limits



Performance & Tuning

Indexes & constraints must be added to the base table

To limit negative performance impact specify an INDEX hint within the crossedition triggers

Editioning views accept SQL optimizer hints

Logical column names must be mapped to an index on the corresponding physical column in the base table

Can not drop retired editions!

Bugs (11.2.0.3) – do not drop edition ORA$BASE

One of the least known Oracle database feature


Limits


SQL> SELECT /*+ INDEX (edview1 idx1)*/ email

FROM edview1 WHERE last_name='King';


dbi services

Any Questions? Please Do Ask!


„We look forward to working with you!“

Jérôme Witt

Consultant - Oracle Certified Professional 11g

Mobile +41 79 961 27 73

[email protected]

www.dbi-services.com







tune my code! code-versionen testen via edition-based redef. - jérôme witt, dbi services

Technology

edition ed3

session edition sql

edition sql desc dba

ae view current edition

object objects

objects editions views

inherited objects

actual objects