+ * 'ProfilerOutputDb' expects a database table that can be created by applying
+ * maintenance/archives/patch-profiling.sql to your database.
+ *
+ * 'ProfilerOutputDump' expects a $wgProfiler['outputDir'] telling it where to
+ * write dump files. The files produced are compatible with the XHProf gui.
+ * For a rudimentary sampling profiler:
+ * $wgProfiler['class'] = 'ProfilerXhprof';
+ * $wgProfiler['output'] = array( 'ProfilerOutputDb' );
+ * $wgProfiler['sampling'] = 50; // one every 50 requests
+ * This will use ProfilerStub for non-sampled cases.
+ *
+ * For performance, the profiler is always disabled for CLI scripts as they
+ * could be long running and the data would accumulate. Use the '--profiler'
+ * parameter of maintenance scripts to override this.