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What's the difference between TRUNCATE and DELETE in SQL
...I've highlighted Oracle-specific features, and hopefully the community can add in other vendors' specific difference also. Differences that are common to most vendors can go directly below the headings, with differences highlighted below.
General Overview
If you want to quickly delete all of the...
How to append text to an existing file in Java?
...h (IOException e) {
//exception handling left as an exercise for the reader
}
Careful: The above approach will throw a NoSuchFileException if the file does not already exist. It also does not append a newline automatically (which you often want when appending to a text file). Steve Chambers's ...
Installing Python 3 on RHEL
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It is easy to install it manually:
Download (there may be newer releases on Python.org):
$ wget https://www.python.org/ftp/python/3.4.3/Python-3.4.3.tar.xz
Unzip
$ tar xf Python-3.*
$ cd Python-3.*
Prepare compilation
$ ./configure
Build
$ make
Install
$ ...
Storing Images in DB - Yea or Nay?
...m
databases win out where transactional integrity between the image and metadata are important.
it is more complex to manage integrity between db metadata and file system data
it is difficult (within the context of a web application) to guarantee data has been flushed to disk on the filesystem
...
Is a Java hashmap search really O(1)?
...se this feature to improve the performance of the hash map. We could instead think about the probability of at most 2 collisions.
pcollision x 2 = (n / capacity)2
This is much lower. Since the cost of handling one extra collision is irrelevant to Big O performance, we've found a way to impro...
Using the scrollwheel in GNU screen
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I believe you can just add a line like this to your ~/.screenrc:
termcapinfo xterm* ti@:te@
Where "xterm*" is a glob match of your current TERM. To confirm it works, ^A^D to detach from your screen, then screen -d -r to reattach, then ls a few t...
.NET - Dictionary locking vs. ConcurrentDictionary
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A thread-safe collection vs. a non-threadsafe-collection can be looked upon in a different way.
Consider a store with no clerk, except at checkout. You have a ton of problems if people don't act responsibly. For instance, let's sa...
Forward an invocation of a variadic function in C
In C, is it possible to forward the invocation of a variadic function? As in,
12 Answers
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How to bundle a native library and a JNI library inside a JAR?
...ibraries for one or more platforms. The basic mechanism is to use System.load(File) to load the library instead of the typical System.loadLibrary(String) which searches the java.library.path system property. This method makes installation much simpler as the user does not have to install the JNI lib...
HTML select form with option to enter custom value
...has a built-in combo box. You create a text input and a datalist. Then you add a list attribute to the input, with a value of the id of the datalist.
Update: As of March 2019 all major browsers (now including Safari 12.1 and iOS Safari 12.3) support datalist to the level needed for this functionali...