Oracle Multitenant - organized by Orient ITM - 12 Jul 2014

Oracle Multitenant
Mahir M. Quluzade
Organized by ORIENT ITM
12 July 2014

2 Oracle Multitenant - Mahir M. Quluzade © 2014 http://www.mahir-quluzade.com
Agenda
 Rethinking Architecture for the Database
 Multitenant Architecture
 Capabilities Enabled
 Managing Shared Resources
 Upgrading to Multitenant

About me
 Broad member of AZEROUG (Azerbaijan Oracle User Group)
 OCE, RAC 11g and Grid infrastructure
 OCP Database 11g Administrator
 OCE Database SQL
 Author of OTN Articles and OTech Magazine
 Central Bank - Oracle DBA
 Oracle Blog : http//www.mahir-quluzade.com

Oracle Database Architecture
 Oracle Instance
– SGA & PGA
– Background Processes
 Oracle Database
– Control Files
– Data Files
– Redo Logs (Online and Archived)
– Parameter and Password file
Pre-12c Oracle Database

Oracle Database Architecture
Requires memory, processes and database files
System Resources

New Multitenant Architecture
Memory and processes required at multitenant container level only
System Resources

Increasing Consolidation
Oracle Database 12g
Schema Consolidation Multitenant Database

Agenda
 Rethinking Architecture for the Database

Multitenant Architecture
Components of a Multitenant Container Database (CDB)
Pluggable Databases (PDBs)
PDBs
Root
CDB
create database …
enable pluggable database
Create CDB
create pluggable database …
Create PDB

Multitenant Architecture
 Multitenant architecture can currently
support up to 252 PDBs
 A PDB feels and operates identically to a
non-CDB
 You cannot tell, from the viewpoint of a
connected client, if you’re using a PDB or
a non-CDB
Database
Link

Unplug / plug
Simply unplug from the old CDB…

Unplug / plug
 Moving between CDBs is a simple case
of moving a PDB’s metadata
 An unplugged PDB carries with it lineage,
opatch, encryption key info etc
…and plug in to the new CDB…

Unplug / plug
Example
alter pluggable database HCM
unplug into '/u01/app/oracle/oradata/…/hcm.xml'
create pluggable database My_PDB
using '/u01/app/oracle/oradata/…/hcm.xml'
Plug
Unplug

Common Data Dictionary
Before 12.1: dilution over time
Database Created
Data
Dictionary
User Data
Meta
Data
Mature Database
Data
Dictionary
User Data
Meta
Data
Tables, Code, Data added
Data
Dictionary
User Data
Meta
Data

Data Dictionary Architecture in a CDB
Oracle Database 12c
OBJ$ TAB$ SOURCE$
…
EMP DEPT
…
OBJ$ TAB$ SOURCE$
…
root
Database Metadata Only
PDB
User Metadata Only User Data
MetadataLinks
 Oracle Database stores metadata about
dictionary objects only in the root
– PDB uses Metadata Link to point to the
definition of object stored in the root
 The data corresponding to a metadata link
resides in its PDB

Multitenant Architecture – Dynamics
 PDBs share common SGA and
background processes
 Foreground sessions see only
the PDB they connect to

0
0.5
1
1.5
2
2.5
3
CRM HCM ERP BI
GB
Pluggable Database
MEMORY
0
0.5
1
1.5
2
2.5
3
CRM HCM ERP BI DW
GB
Pluggable Database
MEMORY
Multitenant Scalability
 Only small increments in memory as
additional PDBs are added
0
0.5
1
1.5
2
2.5
3
CRM HCM ERP
GB
Pluggable Database
MEMORY

Files in the CDB
 Each PDB has its own set of tablespaces
including SYSTEM and SYSAUX
 PDBs share UNDO, REDO
and control files, (s)pfile
 By default the CDB has a single TEMP
tablespace but PDBs may create their
own
Namespaces

Users
 Local users are the successors for
customer-created users in a non-CDB
 A local user is defined only in a PDB
 A local user can administer a PDB
 A common user is defined in the root
and is represented in every PDB
 A common user can log into any PDB
where it has “Create Session” and can
therefore administer a PDB
 The Oracle system is owned by
common users

Common Users and Privileges
 A common user can be granted privileges locally in a PDB (or root)
and therefore differently in each container
 A common user can, alternatively, be granted a system privilege
commonly – the grant is made in root and every PDB, present and
future
 You can create a common role
 A common role can be granted to a common user commonly
 Authorization is checked in the container where the SQL is attempted
considering only the privileges that the user has in that container
Authorization is checked in the same way as as pre-12.1

Agenda
 Rethinking Architecture for the Database Cloud

Manage Many as One with Multitenant
Backup databases as one; recover at pluggable database level
One Backup
Point-in-time recovery
At pluggable database level

Manage Many as One with Multitenant
One standby database covers all pluggable databases

Multitenant for Simplified Patching
Apply changes once, all pluggable databases updated
Upgrade
in-place

Multitenant for Upgrades
Flexible choice when patching & upgrading databases

Improved Agility With Changing Workloads
Expand Cluster to Support Flexible Consolidation Model
Services
Single SGA per
CDB Instance
Node1
CDB Instance 1
Node2
CDB Instance 2
Multitenant Container Database (CDB)

Improved Agility With Changing Workloads
Expand Cluster to Support Flexible Consolidation Model
Services
Single SGA per
CDB Instance
Node1
CDB Instance 1
Node2
CDB Instance 2
Node3
CDB Instance 3
Multitenant Container Database (CDB)

Multitenant for Provisioning
 PDBs can be cloned from
remote CDBs
 PDBs can be cloned from
within the same CDB
Fast cloning of PDBs

Cloning a PDB
Example
create pluggable database HCMBI from HCM
create pluggable database HCMBI from HCM@us.acme.db1
Remote (DB Link)
Local

Per PDB vs per CDB
Common operations on CDB with granular control where appropriate
Single Oracle Software Version
Data Guard
Scheduled RMAN Backups
Some parameters/properties
e.g. homogeneous character set
Redo and Undo
RMAN point-in-time recovery
Ad hoc RMAN backups
Flush shared pool
Parameters where
IsPDB_Modifiable = 'TRUE'
Per CDB Per PDB

Advantages of Multitenant Architecture
Reduced CapEx & OpEx, Increased Agility, Easy Adoption
Self-contained PDB for each application
 Applications run unchanged
 Rapid provisioning (via clones)
 Portability (via pluggability)
Shared memory and background processes
 More applications per server
Common operations performed at CDB level
 Manage many as one (upgrade, HA, backup)
 Granular control when appropriate

Agenda

Managing Shared Resources
Resource management in multitenant environment
High Priority
Medium Priority
Low Priority

Managing Resources between PDBs
 Resource Manager can manage resources on two basic levels:
– CDB level
 How resources are allocate d to PDBs
 Limit the resources utilization of specific PDBs
– PDB level
 Resource Manager can manage the workloads within each PDB

Managing Resources between PDBs
 Using Resource Manager, you can control
– CPU
– Parallel execution servers
– Exadata I/O
– Sessions
 Configure a policy that controls how resources are utilized
– Default configuration that works, even as PDBs are added or removed
 You can change default configuration

Manage CPU
Pluggable Database Shares Guaranteed CPU Maximum CPU
HCM 2 2/4 = 50% 100%
CRM 1 1/4 = 25% 100%
ERP 1 1/4 = 25% 100%
2 Shares 1 Share 1 Share
A CDB Resource Plan uses
shares to specify how CPU is
distributed between PDBs

Agenda

Upgrading to Multitenant
Step 1: Upgrade databases in-place
Upgrade in Place

Step 2: Plug-in upgraded databases

 No application changes required.
Step 3. Change applications to work with Multitenant

Migrate using Replication
① Provision new PDB from Seed
② Replicate using technologies such as
Oracle GoldenGate or Data Pump
New in 12.1, you ask that full database
export and full database import make
maximum use of transportable
tablespaces in the single expdb and
impdb commands.
(Backported to 11.2.0.3.)

Benefit Capability Enabled
Minimize CapEx • More applications per server
Minimize OpEx
• Manage many as one
• Standardized procedures & service levels
• Rapid provisioning
Maximize Agility
• Cloning for development / testing
• Portability through “pluggability”
• Scalability with RAC
Ease of Adoption • Applications run unchanged
Key Benefits

Agenda

Your questions

Mahir M. Quluzade
http://www.mahir-quluzade.com

Oracle Multitenant - organized by Orient ITM - 12 Jul 2014

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Editor's Notes