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Fix documentation error in commit 8703059c6b.

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Etsuro Fujita spotted a thinko in the README commentary.
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Tom Lane
2015-10-01 10:31:22 -04:00
parent 2bbe8a6847
commit b44a55fa95
1 changed files with 1 additions and 1 deletions
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src/backend/optimizer/README
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@@ -254,7 +254,7 @@ lower leftjoin has min LHS of {B} and min RHS of {C,D}. Given such
information, join_is_legal would think it's okay to associate the upper information, join_is_legal would think it's okay to associate the upper
join into the lower join's RHS, transforming the query to join into the lower join's RHS, transforming the query to
B leftjoin (A leftjoin (C innerjoin D) on Pa) on (Pbcd) B leftjoin (A leftjoin (C innerjoin D) on Pa) on (Pbcd)
which yields totally wrong answers. We prevent that by forcing the min LHS which yields totally wrong answers. We prevent that by forcing the min RHS
for the upper join to include B. This is perhaps overly restrictive, but for the upper join to include B. This is perhaps overly restrictive, but
such cases don't arise often so it's not clear that it's worth developing a such cases don't arise often so it's not clear that it's worth developing a
more complicated system. more complicated system.