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由 Bruce Momjian 提交于
< * Allow star join optimizations < < While our bitmap scan allows multiple indexes to be joined to get < to heap rows, a star joins allows multiple dimension _tables_ to < be joined to index into a larger main fact table. The join is < usually performed by either creating a cartesian product of all < the dimmension tables and doing a single join on that product or < using subselects to create bitmaps of each dimmension table match < and merge the bitmaps to perform the join on the fact table. Some < of these algorithms might be patented.
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