Database connection error after last update

Hi,

After last plugin update, the website went very slow and the server was not responding with error message: “Error establishing a datebase connection” ..

This forced me to deactivate the plugin to get the website and server working again immediately.

Then I found this kind of inquiries repeating it self many times for the same article (server is getting around 30,000 inquiry per sec):

LIMIT 1
0	Waiting for table level lock	SELECT * FROM <code>wp_yoast_indexable</code> WHERE <code>object_id</code> = '591789' AND <code>object_type</code> = 'post' LIMIT 1
0	Waiting for table level lock	SELECT * FROM <code>wp_yoast_indexable</code> WHERE <code>object_id</code> = '591789' AND <code>object_type</code> = 'post' LIMIT 1
0	Waiting for table level lock	SELECT * FROM <code>wp_yoast_indexable</code> WHERE <code>object_id</code> = '591789' AND <code>object_type</code> = 'post' LIMIT 1
0	Waiting for table level lock	SELECT * FROM <code>wp_yoast_indexable</code> WHERE <code>object_id</code> = '591789' AND <code>object_type</code> = 'post' LIMIT 1
0	Waiting for table level lock	SELECT * FROM <code>wp_yoast_indexable</code> WHERE <code>object_id</code> = '591789' AND <code>object_type</code> = 'post' LIMIT 1
0	Waiting for table level lock	SELECT * FROM <code>wp_yoast_indexable</code> WHERE <code>object_id</code> = '591789' AND <code>object_type</code> = 'post' LIMIT 1
0	Waiting for table level lock	SELECT * FROM <code>wp_yoast_indexable</code> WHERE <code>object_id</code> = '591789' AND <code>object_type</code> = 'post' LIMIT 1

website: http://www.aksalser.com

Thank you.