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Message Posted: Fri, 11 Jan 2013 @ 15:23:24 GMT
Spool limits are not enforced in the system at the Profile level collectively for users.
The profile simply defines the amount of spool for individual users assigned to the profile.
If two separate users with the same profile of 400GB spool, run 300GB queries concurrently, that is fine as it they both are under their individual limit.
If a single user runs 2 x 300GB queries concurrently they will spool out, as the 600GB of spool will surpass the 400GB limit.
Technically spool is accounted at the AMP level, as Total Spool / #Amps. So skewed queries may spool out because they ran an AMP out of spool, although the total combined spool is less than the total limit.
Be mindful of changing profiles, as it will increase the limit for all Users in that profile, that is something that may get you into performance trouble.
Increasing spool should be one of the last things you do, after you have exhausted all you performance tuning options (assuming the spool was set fairly reasonably to begin with).
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