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Which circumstance does the optimizing choose a product join?
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Answer Posted / ab75150
Product join occurs in 2 circumstances.
1) Your stats are out-dated
2) One table is a substantially huge and the other is very
small. In that case, optimizer identifies that is better to
replicate the smaller tables across all amps and then
complete the join.
In later case, product join is not bad. but if the stats
are outdate, better refresh the stats and go ahead with the
execution.
Incase your stats are good and still optimizer goes the
product join path, if you really want to avoid it, you may
force the optimizer not to choose it with following command
DIAGNOSTIC NOPRODJOIN ON FOR SESSION
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Hi send me the Teradata dumps to my id rajeshanantha@yahoo.co.in Thanks Rajesh. A
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