Implement a way to reduce the size of the fieldlayoutitem table in the Database and in the cache

Issue Summary

As described in the other Feature Request JRASERVER-68168, Jira inefficiently populates fieldLayoutCache due to slow loading and large size of FieldLayoutItems (in the cache and in the Database).

This lack of efficiency with loading/populating the Field Layout cache may lead to various performance issues. For example, if a very high number of of Automation Rules are frequently triggered and need to access this cache, these rules might piled up in the automation queue and complete with a long delay.

What contributes to the size of the DB table fieldlayoutitem is a combination of 2 factors:

• the number of custom fields in the Jira application = X
• the number of Field Configurations (=Field Layouts) in the Jira application = Y

Whenever a new Field Layout is created, X*Y new rows will be added to the table fieldlayoutitem. As a result, if a Jira instance has for examples 4k custom fields and 1k field layouts, the size of the table fieldlayoutitem will be in the range of about 4 million rows.

Here is the problem:

• X*Y new rows are added to the table fieldlayoutitem, regardless if a custom field is using a default field configuration or not
• adding such rows does not seem necessary, especially if most of the fields are using a default configuration

Suggestion

The suggestions are the following:

• Implement a way to reduce the size of the DB table fieldlayoutitem and the cache, so that only the custom fields which are not using the default field configuration are occupying a new row in that table
• Implement some script or upgrade tasks that will get rid of all the "non necessary" rows in the table fieldlayoutitem in the DB (and in the cache)