Add planner support functions for range operators <@ and @>.
These support functions will transform expressions with constant
range values into direct comparisons on the range bound values,
which are frequently better-optimizable. The transformation is
skipped however if it would require double e
Add hint about not qualifying UPDATE...SET target with relation name.
Target columns in UPDATE ... SET must not be qualified with the target
table; we disallow this because it'd create ambiguity about which name
is the column name in case of field-qualified names. However, newbies
have been seen
