If you’re using CM ToolTip glossary pro and noticed an abnormal decrease in page speed on your WordPress installation, that might be caused by an option set in CM ToolTip configuration. It came out my SQL database was full of transients, these entries created by some (usually bad coded) plugins to store data in order to increase SQL requests speed. It turned out the cache system used on CM Tooltip glossary did exactly the contrary in my case.
After few hours looking for a solution to my problem I’ve finally disabled the cache option as shown below :
The site where it happened has few thousands of articles already published, so I’m guessing CM ToolTip glossary was parsing all of them when a user requested the page in order to find items that match the glossary index. SQL overload went so far that several hundreds of thousands transients were created and literally crashed my server after a while.
Clean transients manually and automatically
A plugin that really helped me to analyse how WordPress was reacting to these CM Tooltip glossary settings is Transient Cleaner. I strongly advise any wordpress user to use that plugin as a routine to periodically clean his database. Your site speed will feel the difference.
I also removed search engine plugin Ajax Search Pro, it doesn’t work that well for me and made really bad sql requests.