Edition Based Redefinition - nakdimon.comnakdimon.com/db-oriented/wp-content/uploads/2014/... · Every new edition is created as a child of an existing edition Currently (11.2, 12.1),

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Edition Based Redefinition

Oren Nakdimon

www.db-oriented.com

[email protected]

+972-54-4393763

@DBoriented

© Oren Nakdimon

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http://db-oriented.com/presentations



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WHO AM I?

Chronology by “Oracle years”

Today:

Freelance database expert

Courses

Development

Database Administration

When What Where

Oracle 6/7 1991-1997 Developer IAF

Oracle 8 1997-1998 Server group manager Golden Screens

Oracle 8i/9i 1998-2003 DBA group manager TELEknowledge

Oracle

10g/11g

2004-2011 VP R&D and

Israel Site Manager

Olista

“An expert is a person

who has made all the

mistakes that can be

made in a very narrow

field” Niels Bohr (1885-1962)

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SHARING EXPERIENCE FROM…

A 24x7 system

Millions of end-users

Thousands of concurrent end-users

All around the world

Lots of PL/SQL code

Frequent upgrades

Oracle 11gR2 Standard Edition

Intensive use of EBR

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THE BOTTOM LINE

I think EBR is great!

It is quite a big and complex feature,

but…

It is very easy to start using it

It may take some time to know all the

details and nuances

Warning: as with any other feature,

make sure to test it thoroughly before you

decide to apply it in production

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AGENDA

Application upgrades

Scenarios

Methods

EBR introduction

Upgrade use cases

Requirements

Challenges with online upgrade

Solving with EBR

Tips

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APPLICATION UPGRADES – SCENARIOS

Bug fix

Patch

New application version (minor / major)

Downgrade

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APPLICATION UPGRADES – METHODS

Cold cutover

Warm cutover

Hot rollover

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EDITION BASED REDEFINITION

EBR is a feature set that lets you

upgrade the database component of an

application while it is in use, thereby

minimizing or eliminating downtime

Introduced in 11gR2

EBR is supported in all editions, and

requires no special license

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The fundamental ability is that different

copies of the same object may coexist

Not all objects are editionable

EDITION BASED REDEFINITION

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Edition1

Edition2

PKG_A

JERRY TOM

PKG_A

PKG_A

MY_VIEW

MY_VIEW

TRGR_8

TRGR_8

TABLE_X TABLE_Y




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EDITIONS

Edition is a non-schema object

There must be at least one edition in the

database

The initial edition is ORA$BASE

There is always one database-level default

edition

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EDITIONS – CONT.

Every new edition is created

as a child of an existing

edition

Currently (11.2, 12.1), each

edition may have at most one

child edition

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Ask me later about…

Enabling editions to users

Granting use on editions

Edition1

Edition2

Edition3 Edition3b




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OUR EXAMPLE

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PEOPLE

(table)

PEOPLE_DL

(package)

add | remove

APP_MGR

(package)

do_something




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S B S B Table

APP_MGR PEOPLE_DL

@people_setup

OUR EXAMPLE




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USE CASE 1 – THE REQUIREMENTS

A package body should be changed

No change in package spec

No change in table structure

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USE CASE 1 – THE CHALLENGES

Blocking

Compilation is blocked by active clients

Clients are blocked during compilation

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Tip




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SESSION EDITION

Each session uses one edition at a time

The current session edition:

SHOW EDITION (SQL*Plus)

SYS_CONTEXT(‘userenv’,’session_edition_name’)

To change the session edition:

ALTER SESSION SET EDITION = edition;

Must be the first statement of a transaction 17




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EDITIONED OBJECTS

An editioned object in an edition is either:

Inherited

or

Actual

Note: actualization is irreversible!

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@end_user_session

@use_case_1




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A package spec should be changed


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S B S B

Table

ora$base

APP_MGR PEOPLE_DL

V1 B




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Invalidation

Compilation errors (hopefully not…)

Object dependency

Revalidation occurs automatically when an object is

referenced

Multiple interrelated objects need to be

changed

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S B S B

Table

APP_MGR PEOPLE_DL




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USE CASE 2



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S B S B ora$base

APP_MGR PEOPLE_DL

V1 B

V2 S

Table




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USE CASE 2



22 @use_case_2

S B S B

Table

ora$base

APP_MGR PEOPLE_DL

V1 B

V2 S B B




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A VERY IMPORTANT FOOTNOTE

Source: http://www.oracle.com/technetwork/database/features/avail

ability/ebr-455513.html 23




http://www.oracle.com/technetwork/database/features/availability/ebr-455513.html





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How to identify dependent

objects

Different ways to actualize

Tip




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A new column should be added

It represents a new logic

An existing package should be changed

accordingly

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Invalidation

Code dependent on the table is invalidated (!)

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S B S B

Table

ora$base

APP_MGR PEOPLE_DL

V1 B

V2 S B B




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View Program

Unit

ELIMINATING DEPENDENCY

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Table




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EDITIONING VIEWS

Editioning Views are:

Views (hence editionable)

Deliberately limited:

One per table

May contain only the SELECT and FROM clauses

The FROM clause refers to a single table

The SELECT list may contain only columns and

aliases (no expressions)

DML triggers can be defined on them

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Editioning Views are

the Interface

between the

Application and the

Tables




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Other schema changes that

cause invalidations

And how to handle them

Tip




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Tip




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Tip




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It replaces an existing column

Cutover

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Keeping the old representation and new

representation in sync until the cutover

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CROSSEDITION TRIGGERS

A crossedition trigger is a “bridge” for

moving data between editions

Temporary in nature

Forward crossedition triggers transform

pre-upgrade representation to post-

upgrade representation

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Mass update of the data

Tip




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Tip




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USE CASE 5


It replaces an existing column

Rollover

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REVERSE CROSSEDITION TRIGGERS

Reverse crossedition triggers transform

post-upgrade representation to pre-

upgrade representation

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Tip




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EXPOSING THE NEW VERSION

Database-level:

ALTER DATABASE DEFAULT EDITION = edition;

Session level

Statement level – using

DBMS_SQL.PARSE

Service level

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ORA-04068

After Logon trigger




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Retiring editions

Dropping editions

What’s new in 12c

Jobs and editions

DB links and editions

Whatever you like…





THANK YOU

© Oren Nakdimon

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Oren Nakdimon

www.db-oriented.com

[email protected]

+972-54-4393763

@DBoriented




Documents

Edition Based Redefinition - nakdimon.comnakdimon.com/db-oriented/wp-content/uploads/2014/... · Every new edition is created as a child of an existing edition Currently (11.2, 12.1),