Microsoft SQL Server
Capturing deadlock events
Traditionally, trace flags 1204 or 1222 are used to write information about deadlock events to the SQL Server log. But since SQL Server 2012, there is a default Extended Event session running called system_health that can be used instead. Extended events are stored as XML, and in this post I’ll show a method to extract information when a deadlock occurs and store it in a regular table. By having the deadlocks stored in a table, it is possible to view the history of deadlocks in order to enhance deadlock investigations.