Nintex feature id error messages in SharePoint related to nintex workflow features, you may face. Similar to SharePoint feature id, you need the nintex feature id to get understand the error more.
By time workflow content grow high which will impact performance. So as to improve performance of workflow for sharepoint site containing nintex workflow, we can move nintex database from default all in one content to a dedicated nintex database. Moving nintex database to dedicated content database from common db is called split database.