Posts like this always give me concern because in the effort to be helpful I am providing information that we don’t support doing – direct table modification in SQL.
Just because you have a lab topology to play with is no excuse to not properly backup the database or the use of virtual machine options to restore to a prior saved state, I won’t name names but somebody I know very well decided to proceed with blind confidence and required the assistance of one of the test engineers to reverse his mistakes!
With Group Chat you can post text which at the point of the 513th character automatically becomes a story. The reason behind the design is to value the limited screen space to avoid one person pasting something so large it moves everything off the screen. You may find that 512 characters is not enough and you want to alter this value. Along with this behavior is the default size allowed for a story which means users would have to know the content size ahead of time and recognize they must attach a document instead of a story, it is unlikely most end users are thinking about this detail.
The values are in tblConfig in the pool row
Value Default Maximum Message Limit 512 4096 Story Limit 4096 131072 (128k)
For those of you that are familiar with SQL, I hope this provides you some additional insight and assistance for managing Group Chat.