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What's wrong with nullable columns in composite primary keys?
...keys is not clean relational database design.
If there are two entities A and B where A can optionally be related to B, the clean solution is to create a resolution table (let's say AB). That table would link A with B: If there is a relationship then it would contain a record, if there isn't then i...
Simulate delayed and dropped packets on Linux
I would like to simulate packet delay and loss for UDP and TCP on Linux to measure the performance of an application. Is there a simple way to do this?
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Compiling C++ on remote Linux machine - “clock skew detected” warning
I'm connected to my university's small Linux cluster via PuTTY and WinSCP, transferring files using the latter and compiling and running them with the former. My work so far has been performed in the university's labs, but today I have been doing some work at home that generated an interesting warn...
BeanFactory vs ApplicationContext
I'm pretty new to the Spring Framework, I've been playing around with it and putting a few samples apps together for the purposes of evaluating Spring MVC for use in an upcoming company project. So far I really like what I see in Spring MVC, seems very easy to use and encourages you to write classes...
Why is SELECT * considered harmful?
...s more data to move from the database server to the client, slowing access and increasing load on your machines, as well as taking more time to travel across the network. This is especially true when someone adds new columns to underlying tables that didn't exist and weren't needed when the origina...
var functionName = function() {} vs function functionName() {}
...intaining someone else's JavaScript code. I'm fixing bugs, adding features and also trying to tidy up the code and make it more consistent.
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Test iOS app on device without apple developer program or jailbreak
... has finally introduced a new feature in Xcode 7 that allows you to deploy and run any number of apps on any of your devices, simply by logging in with your Apple ID. You will no longer need a paid Program membership to deploy apps on your own device (and you certainly no longer have to jailbreak yo...
Using Vim's tabs like buffers
...nto 1 tab == 1 buffer is an exercise in futility. Vim doesn't know or care and it will not respect it on all commands—in particular, anything that uses the quickfix buffer (:make, :grep, and :helpgrep are the ones that spring to mind) will happily ignore tabs and there's nothing you can do to stop...
__getattr__ on a module
...ed that all special method lookups on
new-style classes bypass __getattr__ and __getattribute__. Dunder methods had previously worked on modules - you could, for example, use a module as a context manager simply by defining __enter__ and __exit__, before those tricks broke.
Recently some historical...
Does my application “contain encryption”?
... iTunes Connect:
"How do I know if I can follow the Exporter Registration and Reporting (ERN) process?
If your app uses, accesses, implements or incorporates industry standard encryption algorithms for purposes other than those listed as exemptions under question 2, you need to submit for an ERN a...