This document discusses Oracle Database 12c's Multitenant architecture, which allows for more efficient consolidation of multiple pluggable databases (PDBs) within a single container database (CDB). Key benefits include more flexible provisioning of new databases, simplified cloning and upgrades done at the CDB level, and improved resource utilization through workload separation. While Multitenant is only available in the Enterprise Edition, the plug/unplug functionality can provide benefits even for single-tenant use cases.

1. Simplify Consolidation with
Oracle Database 12c
Oracle Multitenant
Maris Elsins
Co-Authors: Marc Fielding, Alex Gorbachev and Oracle!
September 18, 2013

2. Māris Elsiņš
• 8y+ Oracle [Apps] DBA, 3y PL/SQL Developer
• Oracle Applications DBA / TTL at Pythian
• Oracle Certified Master
• Oracle Certified Professional 9i, 10g, 11g, 11i, R12
• Frequent Speaker (15) UKOUG, OUGF, LVOUG, Collaborate, …
• Blogger http://www.pythian.com/blog/author/elsins/
• MarisElsins, Maris.Elsins, ,
• FAN of BAAG (BattleAgainstAnyGuess.com)
2 © 2013 Pythian

3. Who is Pythian?
• 15 Years of Data infrastructure
management consulting
• 170+ Top brands
• 6000+ databases under management
• Over 200 DBA’s, in 26 countries
• Top 5% of DBA work force, 9 Oracle
ACE’s, 2 Microsoft MVP’s
• Oracle, Microsoft, MySQL partners,
Netezza, Hadoop and MongoDB plus
UNIX Sysadmin and Oracle apps
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4. Agenda
• Multitenant Architecture
• Use cases and benefits
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5. © 2013 Pythian5
Multitenant Architecture

6. Pre-12c Consolidation Options
Share
nothing
• Each Database on it’s own server
Share HW
• Multiple virtual machines on the same HW
Share HW
and OS
• Multiple databases on the same server
Share
HW, OS
and DB
• Multiple schemas in the same DB
Flexibility
Efficiency
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7. Consolidation options today (12c)
Share
nothing
• Each Database on it’s own server
Share HW
• Multiple virtual machines on the same HW
Share HW
and OS
• Multiple databases on the same server
Share HW,
OS and DB
• Multiple pluggable databases
• Multiple schemas in the same DB
Flexibility
Efficiency
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= Flexible and Efficient

8. Pre-12c Oracle Database Architecture
Requires memory, processes and database files
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9. 12c Multitenant Architecture
Memory and processes required at Container DB level only
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PDBs
Root
Adding additional PDBs has
only a little memory overhead

10. Files in the CDB
• PDB owns
– User TS data files
– SYSTEM, SYSAUX
– TEMP (optional)
• Root owns
– SYSTEM, SYSAUX
– Redo logs
– UNDO
– TEMP
– Control Files
– (s)pfile
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11. Users and Privileges
• Local users
– Defined only in one PDB
– Connects to one PDB only
– Same as user schemas in
non-CDB
• Common Users
– Defined in Root
– Present in all PDBs
– Connects to PDBs where
“create session” is granted
– Starts with “C##” or “c##”
Authorization is checked in the container where the SQL is attempted
considering only the privileges that the user has in that container
• Locally granted Privileges
– Granted to any user in a
PDB (or Root)
– Applies to the PDB or Root
only
• Commonly granted
Privileges
– Only for common users
– Common roles can be
created
– Applies to all PDBs
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12. Plug / Unplug
Unplug from the old CDB…
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13. Plug / Unplug
…and plug into the new CDB
• PDBs are self-contained,
only metadata need to be
moved.
• Upgrading and patching
is a simple move from
one CDB to another.
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14. Plug / Unplug
unplug…
SQL> alter pluggable database PDB1 close immediate;
Pluggable database altered.
SQL> alter pluggable database PDB1 unplug into '/tmp/PDB1.xml';
Pluggable database altered.
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SQL> create pluggable database PDB2 using '/tmp/PDB1.xml';
Pluggable database created.
…plug

15. How to get to 12c Multitenant?
• In-place Upgrade to 12cand plug into CDB
• Migrate using Replication:
– Create PDB from Seed
– Use GG or DP to move data
• Use Full Transportable Export / Import (DP)
– copy all user data files
– Export metadata from source
– Import to an empty PDB
– Export available in 11.2.0.3
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16. CDB is Like a single database
• One Instance
• One buffer cache and shared pool
• One set of background processes
• Can be backed up all at once
• Can be Data Guard all at once
• Supports hundreds of applications in one CDB
• Do RMAN, data guard configuration once
• Global resource management
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17. CDB are Like Separate Databases
• Isolation of different applications
• No application changes required for consolidation
• Support for public synonyms without conflicts
• PDBs can be backed up individually
• startup / shutdown / recover PDBs individually
• Internal PDB resource management
• A client is unable to tell if it’s a PDB or a non-CDB
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18. Limitations of a Multitenant Architecture
• Same version/patches for all PDBs
• Limited ability to manage settings for each PDB
– Memory tuning for individual PDBs
– Some parameters can’t be set at PDB level.
(local_listener, diagnostic_dest)
• The same character set for all DBs
• Some operations don’t work within the CDB
– RMAN DUPLICATE to clone a PDB
• Maximum of 252 PDBs (too many?)
• Cloning a PDB requires the source to be in read only
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19. © 2013 Pythian19
Use Cases and Benefits

20. Manage as one
• Backups
– Backup whole CDB as one
– Restore/recover the whole CDB or PDBs individually.
• Data Guard
– Configure Data guard for the whole CDB at once
– Database roles are associated at CDB level.
– Switch/Fail-over happens for the whole CDB
– Role changes at PDB level are not possible.
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21. Patch as one
• Install patches once per CDB
• Effective in all PDBs immediately
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22. Upgrade as one
The old version CDB The new version CDB
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23. Simple cloning
Locally
SQL> create pluggable database test2 from test1;
Pluggable database created.
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Remotely using a DB Link
SQL> create pluggable database test2 from test1@remote;
Pluggable database created.
• The source PDB has to be in read-only mode
Storage snapshot ( on ACFS, ZFS Storage Appliance or NetApp?)
SQL> create pluggable database test2 from test1 snapshot copy;
Pluggable database created.

24. Multitenant works with RAC
• Same efficiency – one CDB instance per server
• RAC = Avoid downtime caused by node failures
• Advanced features
– Oracle Database Quality of Service Management
– Application Continuity
• Agility With Changing Workloads and Requirements
– No need to plan ahead which nodes the PDB is running on
– RAC, DG are features of CDB, plug the same PDB to enable these
features
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25. Mixed Workloads
• OLTP peak time is day
• DWH peak time is night
• Pre-12c DBs
– high resource allocation for peak use
– Low resource usage during non-peak
activity
• OLTP + DWH in the same CDB on
the same Hardware = efficient use
of resources
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0
20
40
60
80
100
day night day
OLTP
0
50
100
150
200
Pre-12c
0
50
100
150
day night day
12c
0
20
40
60
80
100
day night day
DWH

26. Perfect for Private Clouds
• Creating a DB
– Rapid provisioning
• From Seed
• From pre-created DB
• Into the requested
configuration
– Simplified cloning
– Quick cloning with copy-on-
write snapshots
• Improved and Simplified
AaaS
• Finally! DBaaS! © 2013 Pythian26
0
5
10
15
20
25
Non CDB PDB Clone PDB using
Copy-on-Write
File System
Time Taken to Provision New
Database (minutes)

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Summary

28. Benefits
• Saving resources
• Plug/unplug entire PDB database
• Rapid PDB cloning and
provisioning
• Separation of roles (PDB admin vs
CDB admin)
• Resource management
• Recovery of individual PDBs
• Quick starting / stopping of PDBs
• Agility
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29. Feature Availability
• Multitenant
– Enterprise Edition only
– Extra cost option
• Singletenant
– CDB with one PDB
• Useful for upgrades (Full Transportable Exp / Imp)
• Ability to use (un)plug feature without consolidation
– SE1 / SE / EE
– No Extra Cost
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30. License costs.
• List prices (August 16, 2013) per CPU
1. Oracle Multitenant 17,500$
2. Database Enterprise Edition 47,500$
3. Real Application Clusters 23,000$
4. Diagnostic Pack 5,000$
5. Tuning Pack 5,000$
6. Partitioning 11,500$
7. Cloud File System 5,000$
• +37% in addition to EE
• +19% in addition to EE + RAC + Part + Diag + Tun
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31. © 2013 Pythian31