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Re: Defragment - which tables to view

From: Adrian Shepherd <Adrian.Shepherd_at_BTINTERNET.COM>
Date: Fri, 17 Apr 1998 23:37:07 +0100
Message-ID: <6h8m3h$o3a$1@mendelevium.btinternet.com>


Slight confusion here. Table fragmentation is logical fragmentation and has nothing to do with disk fragmentation which could be seen as file fragmentation. Use a disk defrag package to physically defragment the physical Oracle data files. Tablespace fragmentation can be seen as a table having two or more extents that aren't contiguous. (Assuming a table with many contiguous extents isn't actually fragmented in the older versions of Oracle) You can query USER_EXTENTS or DBA_EXTENTS to see how many fragments (extents) each object/table has, you can then check to see if these extents are physically contiguous. You may also want to approach the subject of row chaining when thinking about fragmentation issues.

Duke Truong wrote in message <353690AF.5B2A_at_earthlink.net>...
>Hi there
>
>Does anyone knows which tables I should select to determine the disk
>fragment on the tablespace. Sql command provided would be apreciated.
>
>thanks
Received on Fri Apr 17 1998 - 17:37:07 CDT

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