Which is better for map service: XY Event layer or Query Layer

Discussion created by stsnider on Jun 14, 2019

ArcGIS Desktop 10.5.1


I need to publish a dynamic layer to ArcGIS Server that resides in a flat SQL Server database (not a geodatabase).  This is a legacy database that's been around for more than 20 years.  Upgrading it to a geodatabase is not an option currently as there are many integrated legacy systems that depend on it. 


I'm wondering which option would perform better: adding the table as an XY Event layer or making a query layer.  Are these the same thing or are there characteristics that make one better than the other?  I know its not optimal to publish a query layer as a map service, but we need to keep the information dynamic to the database more than we need it to display quickly.  Any suggestions would be appreciated.  Thanks!