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Silver Bullets and Emergency Oracle Tuning
Huge stress levels and late night hours
are an inevitable part of life for an emergency support DBA.
Most of the databases will be unfamiliar and the DBA will only
have a few minutes to assess the problem and create a plan to
quickly relieve the bottleneck.
Only when the easy remedies have failed
is the emergency support DBA called in. When a production
database is in crisis, minimizing downtime is critical.
During this kind of crisis, cost is not
an issue. The clients demand quick fixes, and this often
requires unconventional methods.
These methods are usually driven by a
client that may not appreciate the long-term benefits of a
thoroughly devised fix for the root cause of the problem.
Therefore, the emergency DBA is required to use every weapon in
their arsenal to get the client running as soon as possible.
This arsenal of stopgap remedies is often neither elegant nor
comprehensive.
Functioning as an emergency Oracle
support DBA can be great fun for the adrenaline junky. This
kind of support often requires a unique set of techniques:
-
Fix the Symptom First - The root
cause can always be addressed later.
-
Time is Critical - When a quick fix
is required, instance-wide adjustments are often the best
hope.
-
Be Creative - Traditional time
consuming tuning methods do not apply in an emergency.
Once the silver bullets have done their
job and minimized the bottlenecks, the Emergency Oracle support
DBA can only hope that the client will dedicate resources to the
identification and long-term correction of the root cause of the
problem.
Conclusion
This chapter has been an overview of
Oracle silver bullets and how they are used in practice. The
main points of this chapter include:
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Management is Driven by Costs -
Oracle managers may not always choose the best tuning
solution, especially if it involves risk, delay and high
costs. Instead they often choose silver bullet approaches
like Materialized Views and faster hardware.
-
Know the Bullets - The most common
silver bullets for the Oracle DBA are init.ora parameters,
building indexes, especially function-based indexes, and
using Materialized views.
-
Silver Bullets Come in Many Forms -
There are a large number of silver bullets that can be
applied to Oracle including SGA bullets, instance bullets,
optimizer bullets and hardware bullets.
-
Emergencies are Different - In a
crisis, the luxury of a detailed investigation and test plan
is not allowed. The DBA must be ready to react quickly with
powerful tools that can adjust Oracle and relieve the
bottleneck.
-
Before details on specific silver
bullets are presented, a quick look at how the job role of
the DBA has been changing over the past decade is in order.
The information in the next chapter will include this
affects the DBA’s approach to Oracle optimization.
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