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Home -> Community -> Usenet -> c.d.o.server -> Re: High Water Mark ?
On Fri, 26 Nov 1999 04:34:00 GMT, yewpc_at_rnd.celcom.com.my
wrote:
>The answer is E. but why ?
>Can anyone tell me how each of the above method change the high water
>mark ?
>Actually what is high water mark ? what is it purpose ? what dictionary
>i can use to query about it ?
The high water mark represents the most amount of the space allocated to a table that was ever actually used. If you had a table w/a 50 meg extent, at one time had 30 megs of data in the table, but now have only 20 megs, the high water mark would be at 30 megs.
I believe the issue with conventional vs direct import revolves around the fact that a direct path import sends data blocks directly to the database. In order for that to work, I believe those blocks are always loaded into new space, above the high water mark. A conventional path load essentially does insert statements, and the rows could go into blocks that were already being used. I've never really thought about this exact question before, but this all makes sense based on my understanding of how Oracle works.
Jonathan
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