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Embarrassed Vendors
Most vendor packages are designed with extremely generic SQL so
that they can be easily ported to a variety of database
platforms such as SQL Server, MySQL, and DB2, and they rarely
make customization for Oracle-centric performance. Worst of all,
most vendors do not like being told that their Oracle database
layer needs to be tuned.
Vendors control the schema structures and the application
layers. Even if a user finds sub-optimal SQL statements, they
often cannot access the SQL source code in order to tune it.
These quirky vendor packages are the primary reason that Oracle
offers specialized features such as optimizer plan stability (in
the form of stored outlines) and the new Oracle10g SQL Profiles
feature. In fact, Oracle has a wealth of tools for tuning vendor
applications when the source code cannot be altered.
Emergency Oracle Support
When an Oracle performance problem cripples a mission-critical
database, the DBA always gets the blame. The DBA is under great
pressure during a database emergency and is always the target of
everyone’s attention. During these times of intense stress, the
DBA may not have time for an elegant solution.
Testing a hypothesis on a large running database is like trying
to tune a car while it’s flying down the freeway at 75 miles per
hour. It is impossible to reproduce the conditions of a complex
performance breakdown, so the emergency support DBA must depend
on experience and silver bullets to guide their plan of action.
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