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The text below is an except from the book,
Oracle Performance Firefighting, written by
Craig Shallahamer of
OraPub, Inc.
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©2009, 2010 by Craig Shallahamer. This is copyrighted material.
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Oracle systems have many protection needs. Besides the obvious security requirements, there are control requirements as well. Two broad categories of control are relational structures and memory structures. Latches and mutexes are firmly aligned with memory control.
Another name for relational control is lock management. For example, when the command lock table employee exclusive is issued, that's relational control.
Locks prevent an inappropriate change from occurring. When an Oracle process is waiting for a lock, it posts an enqueue wait. I like to say using enqueues is very mature and boring because they are orderly, structured, and just not a lot of fun. (You'll see that latches are just the opposite.)
©2009, 2010 by Craig Shallahamer. This is copyrighted material.
PleaseOut of respect for those involved in the creation of the book and also for
their familes, we ask you to respect the copyright both in intent and deed. Thank you.
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