Presenter Megan Elphingstone, Senior Oracle DBA for Datavail will show the audience how Datavail has developed a proven method of running Oracle Health Checks.
1. Real Value of Oracle Database
Health Checks
J a n 2 0 1 7
2. 1/23/2017 2www.datavail.com
Welcome!
Megan Elphingstone
15+ years of Oracle database experience
10 years as an Oracle Database Administrator
Favorite part about being a DBA…
I like helping customers and users solve problems and
implementing solutions that are automated, stable, and reliable.
3. 1/23/2017 3www.datavail.com
Health Check: Why, What, When, How
And then what?
Why should I run a Health
Check?
What should I check?
How often should I run a
Health Check?
• OLTP vs
• Warehouse vs
How?
• Manually vs automated
• What tool should I use?
• Should I use a service
provider?
Then what?
• How do I interpret the results?
• How do I react to the information?
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I’m in a crisis, should I run a Health Check?
It may be required by
Oracle for an SR
It could help diagnose the
problem
Users are complaining
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Why do a Health Check on a stable system?
You don’t know what you
don’t know
Do things seem acceptable
when they could be faster?
Are people complaining, but
you aren’t hearing it?
An upgrade is always on the horizon, are
you prepared?
• Ununsable indexes and invalid objects will cause
problems in an upgrade – fixing them now will make
your upgrade go more smoothly
If it ain’t broke, don’t fix it…
• This mentality will leave you unprepared for an
upgrade
• Trouble may be brewing and you won’t know until it
starts to affect users
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What if I never run a Health Check?
Can’t get access to the
system when you need to
Long delays and difficulties
logging in
Unable to replicate the
database accurately
Experience forced software upgrades
performed on the spot rather than
planned for
Are fined for failure to properly comply
with backup and security requirements
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What to look for in a Health Check
Size and Space Issues
• Size of your SGA
• Object size
• Size of database
• Space utilization, file system (ASM?)
• Adequate space for backups
• CPU, disk and memory utilization
• Table space critical and warning threshold levels
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What to look for in a Health Check
System Issues
• Database components
• Backup test
• Recovery test
• Is it a supported version of Oracle?
• Has it been patched?
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What to look for in a Health Check
Performance Issues
• How are the stats being generated?
• Issues related to collecting stats
• Unusable indexes and invalid objects
• Are table space, auto extendable data files used?
• Top buffer gets, reads and lag times
• IO balance across the file system
• Block change tracking
• Wait statistics through the database
• Are you taking advantage of flashback?
• Logging operations
• Corrupt log files
• IO stats: top reads, top writes
• Re-do logs
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What to look for in a Health Check
Security Issues
• Analysis of user accounts
• Dormant accounts present security risks
• Are privileges properly assigned?
• Is recycle bin properly configured?
• Listing of hidden users
• Listing GRANTs on SYS tables
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When should I run a Health Check?
Monthly for high-stress,
high-turnover agile
environments
Quarterly for a growing
user base generating
growing data
Semi-annual for non-
growing, steady-state
user bases
13. 1/23/2017 13www.datavail.com
How to run a Health Check: Orachk
• ORAchk and EXAchk User’s Guide
• Frequently required by Oracle when working an SR
• With 12c it is installed with the software $ORACLE_HOME/suptools/orachk
• Run on demand, via daemon, via cron
• Output can be emailed or stored in a directory
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Show Check Ids
Remove finding from report
ORAchk continued…
• Finding Needing Attention On Database Server
- On Database Server
• Maximum Availability Architecture (MAA) Scorecard
• Finding Passed
- On Database Server
• RDBMS patch recommendation Summary report
• RDMS Patch recommendation Detailed report
• TOP 10 Time Consuming Checks
Oracle orachk Assessment Report
System Health Score is 88 out of 100 (detail)
Table of Contents
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Health Check Monitor
Health Checks can be run via Health Monitor
• Reactive
• Manual
• Scheduled
PL/SQL Package
BEGIN
DBMS_HM.RUN_CHECK('Dictionary Integrity Check', 'my_run');
END;
ADRCI
View Data via Health MonitorViews
• V$HM_RUN
• V$HM_FINDING
• V$HM_RECOMMENDATIONS
17. 1/23/2017 17www.datavail.com
The DB Admin Module includes a health
check
Toad
https://www.toadworld.com/products/toad-for-
oracle/b/weblog/archive/2013/07/07/toad-database-health-check
• Vulnerability assessment
• Configuration (including Oracle RAC and usage of Oracle
options, OEM management packs and Exadata)
• Performance
• Storage
18. 1/23/2017 18www.datavail.com
Have Datavail Do A Health Check
Datavail has hundreds of DBAs
with shared knowledge.
We have a proprietary assessment
tool that reports on a series of 72
tests of database capacity, speed,
resilience, flexibility, and security.
The Datavail Health Check report
is easy to read and understand
Your DBAs may be too busy fighting
fires to be proactive – Datavail can
help.
Datavail can assess database
health as well as provide solutions
to issues.
19. 1/23/2017 19www.datavail.com
Health Check results and responses
Nologging operations
that can result in
unavailability or
unrecoverability
Corrupt log files can
lead to a standby
failure when you
need it
Forced upgrade – you
may be so far behind on
patches that a bug may
crop up and you will be
forced to upgrade as a
solution from Oracle
Failed RMAN backups
may put you out of
compliance with
Corporate policies and
cause major problems if
you need them
Potential space
issues if disk space
and growth isn’t
monitored
20. 1/23/2017 20www.datavail.com
Health Check results and responses
Users with DBA privs
should be evaluated.
Locked accounts
should be deleted
Recyclebin contents
– set up a script to
empty on a regular
basis
Duplicate datafile names,
or files with a double
extension – address
before they become a
problem in a move
Add auto extensible
files to reduce I/O
contention
21. 1/23/2017 21www.datavail.com
Health Check performance issues
1
2
3
5
4
How are Stats gathered
– Use latest method
Are there objects without stats
– gather stats on all objects
unless there is a good reason
How often are redo logs
switching – goal should be 2-3
times per hour
Are database writes/reads
balanced – use auto extendible
files across mount points
Are there unstable plans – this can
be addressed if on EE with
diagnostics pack
22. 1/23/2017 22www.datavail.com
Health Check Performance Issues
• How are Stats gathered – Use latest method
• Are there objects without stats – gather stats on all objects unless there is a
good reason
• How often are redo logs switching – goal should be 2-3 times per hour
• Are database writes/reads balanced – use auto extendible files across mount
points
• Are there unstable plans – this can be addressed if on EE with diagnostics pack