title: MySQL JSON column speed
body: <p>I'm working on a custom CRM for a client who wants "custom fields" which need to be completely dynamic on a per-user basis. I have considered EAV because I cannot simply add these columns to the table. However, after doing some digging, I have settled with using a JSON column in order to store the custom field values in key value pairs.</p>
  
  <p>My concern is the speed of doing lookups on data in this JSON column. How can I ensure that queries which search or perform where's on values in this JSON column remain fast with large amounts of rows in the table?</p>
  
  <p>Or is a JSON column not the ideal solution for this?</p>