Archives of the TeradataForum
Message Posted: Thu, 11 Jan 2001 @ 20:47:06 GMT
| Subj: | | Re: EXPLAIN cost estimates |
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| From: | | Paul Johnson |
I ran an explain today for a simple insert/select on an almost-empty-just-been-installed 5250. The time estimate was 4 minutes to
66 hours 'with no confidence'. Why bother quoting a time range at all if there is known to be no confidence about the
guestimate?
I only use explain output to verify the execution path these days. It seems that the time estimates decrease in usefulness as the
years pass by...or maybe that's just me!
At least the optimiser gets it wrong far less often these days, and that's what really matters.
Paul Johnson
UK
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