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Question and Answer

Tom Kyte

Thanks for the question, Rajwinder.

Asked: June 04, 2001 - 10:39 am UTC

Last updated: June 04, 2001 - 10:39 am UTC


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You Asked

Hi Tom

I Tried my Best but could not understand the concept of Latch.

Could u please explain me with few examples

What is a Latch
How is it created
What are its types
What sre its functions

And all the things Related to it....

Pl. try to give it with more of the examples.


and Tom said...

A latch is a serialization mechanism. In order to gain access to a shared data structure, you must "latch" that structure. that will prevent others from modifying it while you are looking at it or modifying it your self. It is a programming tool.

A latch is a permanent thing in Oracle -- when the Oracle developers ship the data, the entire universe of latches is known. It is compiled into the database. The number of some latches vary - the types of latches are fixed into the code itself.

There is one type of latch -- they are just a serialization device. Many things are PROTECTED by latches -- the library cache, the buffer cache, and so on.

Steve Adams (</code>
 has published a small book on this subject: <code>

if you are really curious, this will go further then you probably really want to.


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Hi i want diffenct types of latches

arjun, March 14, 2014 - 4:10 pm UTC

Hi please any one can explain different types of lathces