# Thread: anyone can give me a good mathematical explanation of checkpoint?

1. Junior Member
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Mar 2002
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please share your analysis though of course there is a different between older and newer version. To me a checkpoint is very important . It is a key factor for performance and recovery..

2. What on earth are you asking? Mathematical explanation of a checkpoint? The only math taking place is incrementing the SCN and generating the sequence to create a starting number, max number, and when to handle the SCN when it reaches max value (Oracle generated, nothing by you).

The SCN is a whole number. A subclass of whole numbers is integers. Integers are numbers such as -3, -2, -1, 0, 1, 2, 3 and so on that extend to plus/minus infinity. SCNs are whole strictly-positive numbers (that excludes zero).

[Edited by stecal on 10-04-2002 at 06:38 PM]

3. Originally posted by stecal
What on earth are you asking? Mathematical explanation of a checkpoint? The only math taking place is incrementing the SCN and generating the sequence to create a starting number, max number, and when to handle the SCN when it reaches max value (Oracle generated, nothing by you).

The SCN is a whole number. A subclass of whole numbers is integers. Integers are numbers such as -3, -2, -1, 0, 1, 2, 3 and so on that extend to plus/minus infinity. SCNs are whole strictly-positive numbers (that excludes zero).

[Edited by stecal on 10-04-2002 at 06:38 PM]
lol

4. Pando & Company
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I know 1 + 1 = 2

and you?

5. http://tahiti.oracle.com

Concepts Guide

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Originally posted by orafup
please share your analysis though of course there is a different between older and newer version. To me a checkpoint is very important . It is a key factor for performance and recovery..
Gee, what a statement :-)

7. Senior Member
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Aug 2000
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extract from the oracle docs

During normal operations, Oracle's DBWn processes periodically write dirty buffers, or buffers that have in-memory changes, to disk. Periodically, Oracle records the highest system change number (SCN) of all changes to blocks, such that all data blocks with changes below that SCN have been written to disk by DBWn. This SCN is the checkpoint.

Hope this helps
Gert

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