How To Be a Great DBA

(c) 2015 Independent SAP Technical User GroupAnnual Conference, 2015
ISUG-TECH 2015 ConferenceISUG-TECH 2015 Conference
I ndexi ng f or Per f or manceI ndexi ng f or Per f or mance
Jef f r ey Gar busJef f r ey Gar bus

AgendaAgenda
 Welcome
 Speaker Introduction
 Indexingfor Performance
 Q&A

Great DBA Series

Since 1997, Soaring Eagle Consulting has been helping enterprise clients improve their overall system
performance at the database tier, arguably the most volatile and critical component of distributed application
architecture. Our clients range in size from fledgling startups through Fortune 100 companies and leading financial
institutions.
Soaring Eagle has been a leader in managed services, database architecture, performance and tuning databases,
while promoting mentoring and training all over the world for over a decade and a half. Many of our employees, and
partners have written books, speak at seminars about leading edge technologies. We have expertise in all
business tiers, financial; health, manufacturing, government agencies and many ecommerce businesses. Whatever
your business needs are we can help improve performance!
Consulting
•Performance & Tuning
•Data Performance
Management
•Emergency Triage
•Performance & Security Audits
•Staff Augmentation
•Project management
•Database architecture
•Scalability assessment and
planning
Training
•Onsite/Web based
• Microsoft
• Sybase
• Oracle
• APM
• Six Sigma
Software
•Application Performance
Management
•Database performance
management
•Database Security
Managed Services
•Remote Database
Management
•Performance management
•Emergency db Service
•Proactive mitigation
•Problem notification
•Problem resolution
Ray Rannala ray@soaringeagle.biz
Partners with

Production DBA vs.
Development DBA
There are 10 kinds of people in the world; “those who understand binary, and
those who don’t.”
There really are 2 basic types of DBA: Production DBAs and Development
DBAs.
This presentation focuses on Production

Production DBA
Failure to perform basic maintenance and monitoring can hurt in
a variety of ways:
Performance issues snowballing
Phases of development become
increasingly difficult
Database corruption, system crash,
or other
When your production database goes down, your business stops
… or a hundred other scenarios
6 - 29 Soaring Eagle Consulting Inc. 08/20/2013

Preventative Maintenance
When servers and databases are not properly maintained:
Performance degrades
Consistency is at risk
Cleanup of ancillary process does not occur
Lack of preventive maintenance is probably the most common omission
to sting the new ASE DBA
Accurate statistics are vital for proper execution plan formation
Failure to keep statistics up to date are frequent causes of later consternation
Check that storage is being used efficiently
7 - 29 Soaring Eagle Consulting Inc. 08/20/2013

Keeping Statistics up to Date
ASE has a cost-based optimizer
Identifies the distribution of the data
Crucial for determining join orders, index selection,
or lack of same
To perform this critical task as often as necessary
Note:
High-volume environments
Statistics - may be observed by:
Querying the systabstats and sysstatistics table
Using the optdiag utility
8- 29 Soaring Eagle Consulting Inc. 08/20/2013

Keeping Statistics up to Date
Tips
Large tables? Update the system based
on sample not entire table
a 10% sampling can be as consistent
as
100% sampling
Update index statistics rather than all
statistics
Update statistics as often as you can
For max speed: update your stats in
parallel9- 29 Soaring Eagle Consulting Inc. 08/20/2013

Reorganize Data
DOL (Data-Only Locking)
RLL (Row-Level Locking)
ASE has changed the storage mechanism
Ads the requirement to clean storage
periodically

Transaction Log Backups
ASE transaction log is an incremental
backup
Make sure you back this up and get it off site
For incremental and redundant backups

Validate Database Consistency
DataBase Consistency Checker (dbcc)
Dbcc checkstorage
Stops small errors from escalating

Soft DBCC Faults
Soft Faults
An inconsistency in Adaptive Server that has not been
determined to be persistent
Usually they are inconsistencies in target database caused by
users updating during the dbcc checkstorage
Can be reclassified by:
Comparing the results of the two executions of dbcc
checkstorage
Running dbcc tablealloc and dbcc checktable after dbcc
checkstorage

Hard DBCC Faults
Hard Faults
A persistent corruption of Adaptive Server
What causes a Hard Fault?
A page that is allocated to a nonexistent table
minimally reduces the available disk storage
A table with some rows that are unreachable by
a scan might return the wrong results
A table that is linked to another table causes the
query to stop

Monitoring
Availability
Resources
Storage space should be monitored by:
Size of the transaction logs
Size of the data
Size available for database and
transaction log dumps
Errorlog space
Are you straining memory? Network? CPU?
sp_monitorconfig
sp_countmetadata
sp_sysmon
sp_object_stats
Continued next slide

Monitoring
Performance
MDA tables
ASE/SAP
Errorlog
Any major errors or anomalies from the
server will be recorded in the
errorlog
Monitor and maintain Errorlog
We recommend continuous monitoring
of the log

Configuration
The configuration you choose is critical to
performance and stability
Make sure you grant sufficient memory to:
The kernel
The resources the DBMS kernel needs
Users
Network
Data cache
Procedure cache
Statement cache

Recording Run-Time Data
sp_configure
This stored procedure will list all system configuration
variables
Configuration settings are also stored in a file under
the $SYBASE directory called <servername>.cfg
Adaptive Server
named <servername>.bak
Historical configurations <servername>.###
Archive a good copy of the results from a run of
sp_configure

Application Performance
Know how to identify what application components are
running slowly?
Common mistake =“throw hardware at the problem”
Only masks the problem while it snowballs

Disaster Recovery
Do you have a disaster recovery plan?
Always ask how each plan could go wrong
Include the location of physical
database dumps and any
configuration data that would be
used to re-construct the server
Test plans extensively
Use least experienced DBA to test it

Database Dumps
Regularly dump each database
All tempdb databases are cleared whenever the
server is started so it is unnecessary to take
dumps of these databases
Get a copy of the backups in a secure off-site location
Keep track and maintain a record of the dumps

Logo Management
Transaction Logs must be watched to prevent them from
filling up
A full log stops all modification to the database
Only way to “prune” is to dump
Use threshold management to avoid "log segment full" errors
To verify how large the logs have grown, use the sp_spaceused stored
procedure or sp_helpsegment logsegment

Script Maintenance
It may become necessary to attempt a complete rebuild of
an Adaptive Server
Have scripts ready that can perform the installation,
configuration, and population of the databases
Keep up-to-date scripts
Keep the scripts on a different machine

Verifying Dumps
"Almost any administrator can perform a backup. A useful
administrator can perform a restoration."
Beware of any bad tapes in the stripe set
Get a separate server set aside for periodic testing
Provides an excellent rehearsal for a real disaster

Device Management
There are a variety of DBMS resources that require frequent
IO
Predictive Analysis
Measure and monitor things like database growth or you
won’t have a way to plan

Physical Architecture
Decisions need to be based upon facts, knowledge of your
business requirements, and experience
Application architecture
DBA’s = good resource when you start to design your
application flow

Software Maintenance
SAP / Sybase maintains its software with releases and point releases –
“SWR” (Software RollUp)
A common approach to dealing with SWRs:
Wait awhile before installing the upgrade
Install it on the development server and test it
Then Install it on your production server
Many shops generally adhere to:
If it ain't broke, don't fix it
If you put off upgrades long enough, eventually Sybase will not
support you
The goal is to not wait too long

Business Continuity
Over 29% of businesses fail after catastrophic data loss
Have a long term plan
Hardware Performance
When ordering your server hardware you should know:
What the DBMS performance has been
Which performance spikes are aberrations and what is
normal
How to maximize the throughput throughout your
bottlenecks

Developer training
Developers have high aptitude for logical coding, often do not
have training in database performance
Often leads to applications passing user test, but with
significant performance issues at rollout
An oft-neglected but badly-needed area of DBA work is mentoring

Personality Attributes of a Great
DBA
Curious/ Always Learning
There is always more to learn
Lunch-and-Learns
Meticulous
Constructively Paranoid
Look for what can go wrong
Frequently takes backups
Review Your Performance
• Technology Savvy
(not afraid of automation)
• Communicative
o Communicate to
management early and
often
o Get involved online
• Strives for Perfection
(Continual Improvement)
• “How can I do this better?”

Summary
DBA activities requires dedicated support
Part-time DBA’s might not have enough time or training
Make sure you have adequate expertise at hand

Annual Conference, 2015 (c) 2015 Independent SAP Technical User Group
QuestionsandAnswersQuestionsandAnswers

Questions?
If you are interested in performance tips for beginner through guru programmers and DBAs
using Microsoft SQL Server, visit my blog at: http://mssqlperformance.blogspot.com/
If you are interested in Sybase ASE Performance and Tuning visit my blog:
http://aseperformance.blogspot.com/

Jeff Garbus - jeff@soaringeagle.biz
813.641.3434
SQL Jeff’s SQL Blog- http://mssqlperformance.blogspot.com/
Sign up for our e-calendar at www.soaringeagle.guru
Follow us on Facebook, Twitter and Youtube!
@soaringeagleDBA
Contact Ray Rannala to register for your
Free SQL Performance Evaluation
ray@soaringeagle.biz – 941.981.391334- 29 Soaring Eagle Consulting Inc. 08/20/2013

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How To Be a Great DBA

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