Subject Re: [firebird-support] Re: detailed join mechanism description (FB 1.5)
Author Ann W. Harrison
Adam wrote:
>> FROM a
>> LEFT JOIN (b join c ON ( = ON ( = b.aid)
> How does this affect the PLAN?

Parenthesis in a series of joins work just like parenthesis in
an arithmetic expression. The expression in parenthesis is
evaluated first, then integrated into the larger expression.
It doesn't seem to be in Helen's book, but is a normal part of
the SQL language, so she may have assumed that everyone knew
about it and concentrated on issues specific to Firebird.