Question

Could you help me to make this query faster. My query is workable, but too slow :'(

I want to get all rows from my table, where value of coloumn word meets more than once.

My query looks like next:

select * from `t` 
where id in (select id from `t` group by word having count(*)>1)

Answer 1

The following query should give you more accurate results… indexing word should improve your performance:

select t1.* 
from new as t1 
join (select word from new group by word having count(*) > 1) as t2
on t1.word = t2.word