Stefan Weiss <[EMAIL PROTECTED]> writes:From <doc/html/sql-select.html>:> | A CROSS JOIN or INNER JOIN is a simple Cartesian product, the same| as you get from listing the two items at the top level of FROM. CROSS | JOIN is equivalent to INNER JOIN ON (TRUE), that is, no rows are | removed by qualification.
I thought that by using the second form, you would be able to do 'explicit' joins, effectivly telling the planner in which order to join multiple tables (in case you have to join 10+ tables)?
They are semantically equivalent, but not necessarily the same from a performance point of view. The potential performance issues are covered elsewhere; I think it would just obfuscate matters to try to include that topic here.
You can imply the issue without obfuscating things. How about:
A CROSS JOIN or INNER JOIN is a simple Cartesian product, the same as you get from listing the two items at the top level of FROM. CROSS JOIN yields the same results as INNER JOIN ON (TRUE), that is, no rows are removed by qualification.
-- The opinions expressed in this message are mine, not those of Caltech, JPL, NASA, or the US Government. [EMAIL PROTECTED], or [EMAIL PROTECTED]
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