Re: Chronic Performance Problems

From: Bert Scalzo <bscalz01_at_7-11.com>
Date: Fri, 24 Jul 1998 09:19:13 -0500
Message-ID: <6pa5e7$5g1$1@news.ses.cio.eds.com>

I'm assuming that you have an application problem (i.e. I am assuming that you have a competent Oracle DBA who has tuned Oracle for your hardware, OS and application size/nature).

The problem may be in one of two areas. The first is locking (as pointed out by another reply). Often, database designers implement foreign keys
(referential integrity) in the database without placing an index on the FK
columns. This is a huge mistake in an Oracle database. With no indexes, Oracle places table level exclusive locks on parent table in a parent/child situation. These mystery locks will cause exactly the behaviour you describe
(i.e. each user makes system that much slower).

The other problem may be in the SQL. But tuning application SQL is an art that is way to difficukt to elaborate on in a single message. The best reference I can suggest is O'reilley publisher's "Oracle Perfromance Tuning" book. The chapters on SQL tuning are pure gold ...

Bert Scalzo
DBA
EDS, Plano TX Received on Fri Jul 24 1998 - 09:19:13 CDT