I'm using SQL Server Profiler to trace application activity, but
the Profiler logs aren't showing some commands that I know the
application issued. Is Profiler reliable? Why is it missing
commands?  Profiler is reliable. To understand the behavior
you're seeing, you need to differentiate between Profiler, which
is simply a GUI client application, and SQL Trace, which refers
to a collection of server-side components that collect the
events and data columns you want to see. Profiler makes using
SQL Trace easy by providing a GUI wrapper, but you can use T-SQL
to call the underlying SQL Trace procedures and functions
without using the GUI.  The case of the missing events you
describe is a result of a Microsoft design decision to minimize
the risk of the Profiler GUI significantly degrading server
performance. Occasionally, the Profiler GUI client can't consume
the information it's tracing fast enough to receive and display
all of the trace events. Rather than slow down SQL Server or run
the risk of capturing only