On Fri, Apr 22, 2016 at 4:14 PM, Victor Yegorov <vyegorov(at)gmail(dot)com> wrote:
>> EXPLAIN SELECT * FROM book WHERE name = 'Harry Potter' UNION SELECT * FROM
...
> Queries return different number of rows, meaning they're not fully
> equivalent.
IIRC plain-EXPLAIN returns estimates, you need explain analyze to be comparable.
Francisco Olarte.