Change is required. Atlassian engineer's blog

  Hi, awesome community,    Each time about Jira performance degradation I read a recommendation for application level is do the cleanup of custom fields. In short, that’s a great option for performance, UX and date clean purposes.  Sometimes a good explanation of the existing situation will help many administrators, developers, Jira configurators to understand why we need to pay performance for our flexibility.  In this article, I will describe the standard type of custom fields, as nonstandard can be implemented in another way with another side effect and next time will describe why configuration context is good and for what it was implemented.   Fundamentally Generally, Custom fields based on 3 tables in Jira, you can check here for different major schemes. (e.g. for the newest schemes you can see split user picker filter).  Feel free to double check:  https://developer.atlassian.com/server/jira/platform/database-schema/   So that’s the EAV data model with small improvements. ( http