>> SELECT * FROM test WHERE (name='b' and name2>'a') OR (name>'b') ORDER BY
>> name,name2 ASC LIMIT 1;
> Write that WHERE clause instead as:
> WHERE name>='b' AND (name>'b' OR (name='b' AND name2>'a'))
> This is logically equivalent, but it gives the planner a better handle on
> how to use an index scan to satisfy the query.
I thought the planner had an automatic rewriter for these situations.
It'd be interesting to see an EXPLAIN ANALYZE output to see if it's indeed
rewritten.
>> SELECT * FROM test WHERE (name='b' and name2<'a') OR (name<'b') ORDER BY
>> name,name2 DESC LIMIT 1;
> That needs to be ORDER BY name DESC, name2 DESC (the direction indicator
> applies per-column and not to the output ordering). Same goes for the
> WHERE clause in this query as the previous one, too.
You're right, I screwed up !
Sorry ;)