Bad Query

Bad Query on showthread.php:

Code:

SELECT t_id, t_time, t_src_url, t_dest_url, t_type, t_postid, t_postcount, t_threadid, t_page, t_title, t_text, t_approve
FROM " . vbseo_tbl_prefix('linkback') . "linkback
WHERE t_incoming=1 AND t_deleted=0 AND " . ($ismod?'':'t_approve>0 AND ') . "t_threadid = '" . $thread['threadid'] . "' " . "ORDER BY t_time " . (preg_match('#^(asc|desc)$#i', VBSEO_DEFAULT_LINKBACKS_ORDER) ? VBSEO_DEFAULT_LINKBACKS_ORDER : "DESC")

This is causing a filesort.
I suggest to change the indexes to have the sortfield included.

Also, this query gets executed even if there are no linkbacks - which is mostly the case (approx. 5% of all threads in the board I monitored do have linkbacks).

I suggest to add a flag to thread table to avoid this query if it isn't necessary.

Is there anything I could do to stop this query?

Hello,

thank you for suggestion. We try to avoid altering existing vB db tables if possible.

I fully understand that, but I tend to disagree

Optimizing performance is very important, especially for Big Boards.
And this query seems mostly useless (as the vast majority of threads does not have linkbacks).

Thereofre I would like to disable it if there is no data.

Again, thank you for suggestion (my reply didn't mean that it will be ignored )

Thank-you for bringing this up Andreas, we've added a new field in vBulletin's thread table to keep track of the number of approved incoming linkbacks, allowing us to avoid that extra sql query on showthread pages.

Although this is a lightweight query, as you know, we are always looking for ways to improve vBSEO's performance... a bunch of marginal improvements become a substantial improvement.

Thanks again.