I have created filtering system where is executed WordPress Query with lots of meta_query data. In total there are 24 possible filters with various type and compare values.
At the moment there is ~2800 rows within filtering is executed.
Of course, filtering is very slow, sometimes it takes 30-60 seconds to execute filtering and display some results. After 5-6 such filtering action there is Warning: mysqli_query(): MySQL server has gone away warning.
I am aware of SQL INDEX method, but how can we apply it to WordPress database? Is there any other way to improve filtering speed time in WordPress? What are your suggestions?
Thank you for help.