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Cartesian product could be the default behavior if you select from multiple tables. I'm not sure what the standard says about this one.
by rzzzt 8y ago
Cartesian product could be the default behavior if you select from multiple tables. I'm not sure what the standard says about this one.
- CuriousSkeptic 8y agoIt is. On the topic as such, besides ON and WHERE there is also USING and NATURAL. Som very influential db-people have argued that NATURAL should be the only supported join. Checkout the third manifesto. ON as such allows for outer joins, something you can’t do starting with a Cartesian product. But Oracle has syntax for outer joins using WHERE if you prefer that.
- rzzzt 8y agoAah, very good! Outer joins could be achieved with NVL and a suitable default value, if you don't want to do the (+) thing? Edit: you don't get to pair all rows from one table with an all-NULL "fictional" row from the other table in a cartesian product, so the answer is no