Re: Please a parameter to disable undo, like _disable_logging

  • From: Tanel Põder <tanel.poder.003@xxxxxxx>
  • To: <oracle-l@xxxxxxxxxxxxx>
  • Date: Thu, 7 Oct 2004 00:55:28 +0300

> Or I'm wrong.

Yep, you've made the wrong conclusion.

The reasons why you can't see nor modify a table after you've done a direct
path insert into it, is that Oracle doesn't advance high water mark to the
end of newly formatted blocks before commit (this allows efficient "undo"
for this transaction by just not moving hwm to new location during rollback.
Things get more complex with indexes, though).

So, if your session would be allowed to see a table right after direct path
insert, we could get wrong query results because full table scan for example
only scans up to current HWM and knows nothing about the newly formatted
blocks above it...



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