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or 10 compelling reasons why you may need a catalog database (alternative title). The title of this session is on purpose thought provoking. The author is an experience Oracle DBA in Oracle backup & recovery area. During the presentation he will go through top reasons why you may need to implement RMAN catalog database and give you additional ideas on how you can improve your backups leveraging additional benefits provided by RMAN catalog database. The author will explain in what cases and why you may not need the catalog database. You will go away with a clear understanding on how to benefit from RMAN catalog database and when it may be optional. This is another presentation from author's popular RMAN papers.
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You most probably don't need an RMAN catalog database
Introduction to the whitepaper
Yury Velikanov & Community
Sunday, Sep 22, 2:15 PM - 3:15 PM Moscone West - 3014
Session ID# UGF9741#OOW13 @yvelik
About Yury
Google: Yury Oracle[phone|email]
Twitter, LinkedIn, Blog, Slideshare, YouTube
Oracle ACE DirectorOracle Certified Master (9i/10g/11g + 15 OCP certificates)
Oracle DBA 15+ years (42+ months working for Pythian)
10 Problems with your RMAN backup script (author)12 000+ views on SlideShare.net
About Yury
Google: Yury Oracle
10 Problems with your RMAN backup script (author)12 000+ views on SlideShare.net
About Pythian• Recognized Leader:
– Global industry-leader in remote database administration services and consulting for Oracle, Oracle Applications, MySQL and Microsoft SQL Server
– Work with over 250 multinational companies such as Forbes.com, Fox Sports, Nordion and Western Union to help manage their complex IT deployments
• Expertise:– Pythian’s data experts are the elite in their field. We have the highest concentration of Oracle ACEs on
staff – 10 including 3 ACE Directors – and 2 Microsoft MVPs. – Pythian holds 7 Specializations under Oracle Platinum Partner program, including Oracle Exadata,
Oracle GoldenGate & Oracle RAC
• Global Reach & Scalability:– Around the clock global remote support for DBA and consulting, systems administration, special
projects or emergency response
Community involvement
Agenda• Introduction• Why RMAN catalog is an overhead? / COST• Cases when catalog database is a MUST• Benefits of using RMAN catalog / VALUE
• Catalog use-cases– Catalog & MML integration– Catalog & DR– Catalog & FS
• Practical hints for catalog usage
CTL vs DB
DB Catalogdoesn’t provide more
HISTORY!
Introduction – Why?• Many DBAs use RMAN catalog because
– It was a default option in 8.0– It is recommended by Oracle– It was created before them
• Many DBAs don’t– Use most of the catalog benefits– know how to assess cost involved– know how to justify catalog existence
@dbareactions
COST
Complexity
RMAN catalog is an overhead COST• IMPLEMENTATION COST• MAITENANCE & RUNNING COSTS
• DEPENDENCIES• DOWNTIME• AVAILABILITY• TUNING• BACKUP
•COST per database
- More databases - less cost- Cost vs Risk
A MUST
RMAN catalog database is a MUST• Disaster Recovery
– Data Guard (standby database)– Backups from both DR sides– Shared backups media
RMAN catalog database is a MUST• Control File size is way to big
– control_file_record_keep_time– Manage retention (if applicable)– Restore alternative MML handle
RMAN catalog database is a MUST• KEEP
– Keep a backup for longer than current retention policy allows– Long term backups need a special care and should be treated
as archiving• MML retention should be adjusted as necessary• Other tape pool / file system than regular backups• oracle database software & operational system
– There are alternative ways (file system)
• RESTORE PREVIEW + OS copy• BACKUP + UNCATALOG
VALUE
RMAN catalog Benefits / VALUE
• Additional bird level view - control level– Many databases– Small DBA team– Scheduling issues– Manager’s view
RMAN catalog Benefits / VALUE
• Volumes & Throughput monitoring– Day to day monitoring – Report deviations (archived logs)
– Troubleshooting data– Tuning (compression, IO vs CPU vs TIME)
– Chargeback
Capacity planning / VALUE• Challenge (centralized NFS)
– Used for many databases backups– Retention policy varies– Incremental backups + Weekly cycles– RAC multiple backups from different nodes
• Solution – Catalog DB– Centralized data for all databases– Regular data snaps– Custom data analysis tables
RMAN catalog Benefits / VALUE• MML & Catalog DB
– Tends to have longer retention policy• Often retention policy isn’t managed by RMAN
– Simplifies and unifies controlfile recovery• There are alternatives, e.g. MML handle from log files
RMAN catalog Benefits / VALUE• RMAN scripts
Pros– Standard way to backup– Centralized control / easer change
Cons– Dependency from RMAN catalog– Limited syntax
• About Stored Scripts: Any command that is legal within a RUN command is permitted in the stored script.
!shell rules!
VALUE• Additional high-level view of backups• Volumes & Throughput monitoring• Information for Capacity planning• Simplifies controlfile recovery (MML)
• Repository for generic RMAN scripts
Catalog Doesn’t• Keep longer history• Replace control file backups
CATALOG USE-CASES
MML, DR, FS
Catalog & MML integration• Control File Auto recovery (challenge)
– How it works• CONFIGURE CONTROLFILE AUTOBACKUP ON• standard handle name (%F format)c + {database ID} + {date} + {XX}
• XX - hexadecimal incremental from 00 to FF– Restore
• Restore freshest controlfile• RMAN Tries FF, FE, ….. 01, 00
– MML 1 round trip 2-5 minutes• 240 roundtrips = 8-20 hours
maxseq and maxdays
Catalog & MML integration• Alternative control file restore options
– MML REPOSITORY– RMAN LOG– HANDLE name
• RMAN: “ENV=” or “format”
• Catalog addresses– Difficulties in MML & DBA communications– Absence of MML access– Standard way to restore (easier)
Catalog, MML & RETENTIONRMAN rarely used for retention management
– Typically there are many MML clients• File systems• MS Exchange / Lotus Domino• Other databases
– There are pools to send backups to• Weekly• Monthly• Custom
There is a synchronization challenge
Catalog & Disaster Recovery• Disk based backups are local
– Accessible from one site only
• Tape based backups are global– Accessible from both sites
• Review the SITE_KEY column in RMAN catalog views• KEY: CATALOG disk based backups on other site
“Backup and Recovery Reference 11g R2”– “RMAN Backups in a Data Guard Environment”
Catalog & File System => MML• Simple unless ….
• Relies on file system to tape backups– Strong recommendation to use MML integration
• Missing backups• Too many copies for SOME backup sets
– If you use • Don’t use DELETE OBSOLETE• RESTORE … PREVIEW• Manual synchronization
PRACTICAL HINTS THE CATALOG USAGE
Practical hints for catalog usage
• DBID must be different for all databases• Do not separate Development & Production• To use or not to use RMAN catalog stored scripts?
• Use resync catalog• RMAN setup for catalog DB failures• Introduce two catalog DBs to ensure HA
CONCLUSIONS
Whitepaper!
Catalog makes it simple
• RMAN Catalog is an overhead• You may manage without it• However an RMAN Catalog
– simplifies backup management– adds additional benefits– reduces risks– there are other special cases
• Cost is opposite proportion to DB count• Consider leveraging other catalog DB benefits
If you don’t use catalog DB
• Make sure that– control_file_record_keep_time is greater than
maximum retention period you may use– You have an easy access to archive of RMAN LOG
files– You have knowledge & access to MML server
• at least you have a best friend in tapes management team
• Assess catalog DB benefits on regular basis
CTL vs DB
Google: Oracle YuryBlog, Twitter, Linkedin, ACE … email, phone number
Whitepaper!
Session ID# UGF9741#OOW13 @yvelik
THANK YOU
Google: Oracle Yury
Whitepaper!