A page split typically occurs when an INSERT or UPDATE statement is adding data to a page but there is no space left to do so. In this case, SQL Server creates a new page and moves some of the data to it, thus a splitting of the page. This is a fairly normal process to occur when data is being added to the database. However, too many page splits can cause fragmentation and can hurt performance.
This custom metric allows DPA to collect the data so it can be correlated to other metrics and performance data.
Note that this is a delta metric, meaning DPA will take 2 values from the query and use the difference as the value.
