This type of tuning requires insight
into what these tasks are and how they??™re being executed.
As mentioned earlier, an in-depth discussion of all the various tuning points for an
Oracle database is beyond the scope of this book. However, there is a set of common
tasks that typically result in excess CPU consumption. Some of the usual suspects to
examine if you encounter a CPU resource shortage on your database server include
the following:
Bad SQL
Poorly written SQL is the number one cause of performance problems. An Oracle
database attempts to optimally execute the SQL it receives from clients. If the
SQL contained in the client applications and sent to the database is written so
that the best optimization plan Oracle can identify is still inefficient, Oracle will
consume more resources than necessary to execute the SQL. Tuning SQL can be
a complex and time-consuming process because it requires an in-depth understanding
of how Oracle works and what the application is trying to do. Initial
examinations can reveal flaws in the underlying database design, leading to
changes in table structures, additional indexes, and so on.
Pages:
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408