Question

I have two tables. One is a click-log, that records the exact time we received a click. The 2nd is a dollars / day table that records the amount we earned each day with a particular site.

I need to calculate the daily CPC for each site. The query bellow is working, but takes almost a minute.

Here’s the result of explain:

id  select_type     table           type    possible_keys       key     key_len     ref     rows       Extra
1   SIMPLE          click_log       ALL     url_id,click_time   NULL    NULL        NULL    1404209    Using where; Using temporary; Using filesort
1   SIMPLE          daily_dollars   ref     url_id,date         date    3           func    6          Using where

And the query:

SELECT date( click_log.click_time ) AS DAY,
       click_log.shorturl AS site,
       daily_dollars.money AS earned,
       count( click_log.click_id ) AS clicks,
       daily_dollars.money / count( click_log.click_id ) AS CPC
FROM `yourls_log` AS click_log, yourls_url_money AS daily_dollars
WHERE click_log.click_time >= "2011-07-01"
    AND click_log.url_id = daily_dollars.url_id
    AND date( click_log.click_time ) = daily_dollars.date
GROUP BY DAY , click_log.shorturl

Anything I can do to speed this up?

Table Structure:

yourls_log
----------
click_id
click_time
shorturl
url_id

yourls_url_money
----------------
id
url_id
date
money

Answer 1

Not sure why, but this is much faster (1.5 seconds):

SELECT m.date, c.shorturl, m.money, c.clicks, m.money / c.clicks AS CPC
FROM yourls_url_money AS m
LEFT JOIN (

SELECT date( click_time ) AS
DAY , url_id, shorturl, count( click_id ) AS clicks
FROM yourls_log
WHERE click_time >= "2011-07-01"
GROUP BY DAY , url_id, shorturl
) AS c ON m.url_id = c.url_id
AND m.date = c.day
WHERE date >= "2011-07-01"