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Archives of the TeradataForum
Message Posted: Tue, 26 Aug 2014 @ 21:56:20 GMT
| Subj: | | Re: Left Join leading to product Join |
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| From: | | Walter, Todd |
The product join in step 11 is a very special one that is unlikely to be the cause of your query running out of spool. For this case, the
optimizer knows for certain that spool 3 is a single row that is to be joined to all the rows of spool 21. If your statistics are correct and the
optimizer estimates are correct, spool 21 appears to be small as well so both the cost and output of step 11 should be small.
It looks like all the estimates in this query are small so it is not apparent where it would likely run out of spool. The query will need to be
broken down into segments - eg select from each view with the where criteria - in order to figure out where the estimates are wrong or the
spooling is skewed or significantly larger than the optimizer expects.
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