I turned on Devel query log and at the bottom of my pages it shows the log with the number of executed queries and ms. When i visit any admin page for example /admin/appearance i have following entries in my query log:
_update_cache_clear 73ms DELETE FROM cache_update WHERE (cid = :db_condition_placeholder_0)
DrupalDatabaseCache::clear 81.9ms DELETE FROM cache_bootstrap WHERE (cid = :db_condition_placeholder_0)
As i know, it shouldn't be more than a 5ms. I am using Xcache on my server with 16gb RAM. What's the culprit?
PS when i am visiting non-admin pages they all are loading very fast.