Row chaining [message #170742] |
Fri, 05 May 2006 01:12 |
gajini
Messages: 262 Registered: January 2006
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Senior Member |
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Hi,
Please anyone explain me,what is row chaining & row migration?
Thanks,
Gajini
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Re: Row chaining [message #170750 is a reply to message #170742] |
Fri, 05 May 2006 01:19 |
Frank Naude
Messages: 4587 Registered: April 1998
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Senior Member |
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A simple search on google or this site would reveal the answer:
"Row migration occurs when a database block doesn't contain enough free space to accommodate an update statement. In that case, the server moves the row to another block and maintains a pointer to new block in the row's original block."
"Row chaining in contrast, occurs when no single db block is large enough to accommodate a particular row. This is common when a table contains several large data types. It will then reside in multiple database blocks."
Source: http://www.orafaq.com/forum/t/165/2/
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