In theory, a static method should perform slightly better than an instance method, all other things being equal, because of the extra hidden this parameter. In practice, this makes so little difference that it’ll be hidden in the noise of various compiler decisions. (Hence two people could “prove” one better than the other with disagreeing … Read more
Ok, I have tested adding, iterating and removing elements from both an array and a set. I ran a “small” test, using 10 000 elements and a “big” test, using 100 000 elements. Here are the results. Adding elements to a collection It would seem that the .push array method is about 4 times faster … Read more
When you COUNT(*) it takes in count column indexes, so it will be the best result. MySQL with MyISAM engine actually stores row count, it doesn’t count all rows each time you try to count all rows. (based on primary key’s column) Using PHP to count rows is not very smart, because you have to … Read more
You can still do this in top. While top is running, press ‘1’ on your keyboard, it will then show CPU usage per core. Limit the processes shown by having that specific process run under a specific user account and use Type ‘u’ to limit to that user
I totally agree with the opinion that premature optimization is something to avoid. But it’s true that the Java VM has special bytecodes which could be used for switch()’s. See WM Spec (lookupswitch and tableswitch) So there could be some performance gains, if the code is part of the performance CPU graph.
please add this line into your app theme <item name=”android:windowDisablePreview”>true</item> for more information : https://developer.android.com/topic/performance/vitals/launch-time#themed
Django 1.6 (released Nov 2013) introduced the convenience methods first() and last() which swallow the resulting exception and return None if the queryset returns no objects.
If your page does not modify any session variables, you can opt out of most of this lock. <% @Page EnableSessionState=”ReadOnly” %> If your page does not read any session variables, you can opt out of this lock entirely, for that page. <% @Page EnableSessionState=”False” %> If none of your pages use session variables, just … Read more
Check it. static public void Main(string[] args) { Stopwatch w = new Stopwatch(); double d = 0; w.Start(); for (int i = 0; i < 10000000; i++) { try { d = Math.Sin(1); } catch (Exception ex) { Console.WriteLine(ex.ToString()); } } w.Stop(); Console.WriteLine(w.Elapsed); w.Reset(); w.Start(); for (int i = 0; i < 10000000; i++) { … Read more
First of all, in your example you make tests on a “data.frame” which is not fair for colMeans, apply and “[.data.frame” since they have an overhead: system.time(as.matrix(m)) #called by `colMeans` and `apply` # user system elapsed # 1.03 0.00 1.05 system.time(for(i in 1:ncol(m)) m[, i]) #in the `for` loop # user system elapsed # 12.93 … Read more