Question

I am running this query.

SELECT dom,
COUNT(url) AS counted
FROM results 
GROUP BY dom
ORDER BY COUNT(url) DESC;

I have dom indexed but I cant index url because its a longtext. what can I do to make it faster?

Answer 1

count(url) means to count rows that url field is not null. Perhaps you can increase performance creating and index like:

create index idx__1 on results  (dom, url (1));

And then change your query to:

SELECT dom,
COUNT( left(url,1)) AS counted
FROM results 
GROUP BY dom
ORDER BY counted DESC;

RDBMS only need index, no need to take data from table, if you only ask for both listed fields.