atulbansal

Select count (distinct id) FROM

This query is incomplete. For me it started happening when I changed the main query and removed the DISTINCT and GROUP BY to increase the performance.

I checked the template-functions-link.php. It has

posts_nav_link function towards the end.

An echo on $fromwhere variable returned nothing.

Replacing this line

preg_match(‘#FROM\s(.*)\sGROUP BY#siU’, $request, $matches);

By this

preg_match(‘#FROM\s(.*)\s#siU’, $request, $matches);

fixed it.

It was trying to get table name by parsing the initial query and since I had removed the group by from it, it could not parse it properly.

Atul Bansal

sumocomputers,

I have been facing the same issue with over 16000 posts and have seen the performance of my site degrade. But I just put in a solution that did the trick. My initial load query is down from 6.8s to 0.4 seconds and the heaviest category lookup has come down from 4.3 seconds to .4 seconds as well.

You will have to edit [wp-includes/classes.php] file

Look for the line

$request = ” SELECT $distinct * FROM $wpdb->posts $join WHERE 1=1″ . $where . ” GROUP BY ” . $groupby . ” ORDER BY ” . $orderby . ” $limits”;

And replace it by

$request = ” SELECT * FROM $wpdb->posts $join WHERE 1=1″ . $where . ” ORDER BY ” . $orderby . ” $limits”;

That basically removes the unnecessary DISTINCT on ID which is a primary key in wp_posts table anyway and cannot be duplicated. The distinct and group by are the real killers.

Atul Bansal (http://www.sahihai.com)