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Why does X[Y] join of data.tables not allow a full outer join, or a left join?
...f a philosophical question about data.table join syntax. I am finding more and more uses for data.tables, but still learning...
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What characters are allowed in an email address?
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See RFC 5322: Internet Message Format and, to a lesser extent, RFC 5321: Simple Mail Transfer Protocol.
RFC 822 also covers email addresses, but it deals mostly with its structure:
addr-spec = local-part "@" domain ; global address
local-part ...
How can I profile C++ code running on Linux?
... a profiler, use one of the suggested ones.
However, if you're in a hurry and you can manually interrupt your program under the debugger while it's being subjectively slow, there's a simple way to find performance problems.
Just halt it several times, and each time look at the call stack. If there...
Should I always use a parallel stream when possible?
With Java 8 and lambdas it's easy to iterate over collections as streams, and just as easy to use a parallel stream. Two examples from the docs , the second one using parallelStream:
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Apache Tomcat Not Showing in Eclipse Server Runtime Environments
I have tomcat 5.5 installed, running and verifiable at http://localhost:8080/ . The Tomcat menu option appears in the Eclipse menu bar and I can start and stop Tomcat from there. In Eclipse, it does not show as a Server Runtime Environment in Window - Preferences - Server - Runtime Environments, no...
Why do people say that Ruby is slow? [closed]
I like Ruby on Rails and I use it for all my web development projects. A few years ago there was a lot of talk about Rails being a memory hog and about how it didn't scale very well but these suggestions were put to bed by Gregg Pollack here.
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What is the difference between Amazon S3 and Amazon EC2 instance?
I need to create a web application using php mysql and html. The no.of requests and data will be very high. I need Amazon server space.
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AWS: How to disable all services?
I was dorking around with AWS (and related services), hoping that I could stay in the Free Tier, like I do when I'm exploring Google App Engine.
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What is the advantage of using REST instead of non-REST HTTP?
...dy really agrees on what REST is. The wikipedia page is heavy on buzzwords and light on explanation. The discussion page is worth a skim just to see how much people disagree on this. As far as I can tell however, REST means this:
Instead of having randomly named setter and getter URLs and using GET...
How to handle :java.util.concurrent.TimeoutException: android.os.BinderProxy.finalize() timed out af
...mber of TimeoutExceptions in GcWatcher.finalize, BinderProxy.finalize , and PlainSocketImpl.finalize . 90+% of them happen on Android 4.3. We're getting reports of this from Crittercism from users out in the field.
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