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What is an index in SQL?
...
An index is used to speed up searching in the database. MySQL have some good documentation on the subject (which is relevant for other SQL servers as well):
http://dev.mysql.com/doc/refman/5.0/en/mysql-indexes.html
An index can be used to efficiently find all rows matching some c...
What do all of Scala's symbolic operators mean?
...ode has three automatic imports:
// Not necessarily in this order
import _root_.java.lang._ // _root_ denotes an absolute path
import _root_.scala._
import _root_.scala.Predef._
The first two only make classes and singleton objects available. The third one contains all implicit conversions a...
How to write a CSS hack for IE 11? [duplicate]
... you still have to check for selector specificity. Putting something like :root before the IE specific selectors fixes the problems.
– wortwart
Apr 14 '15 at 11:13
...
PHP_SELF vs PATH_INFO vs SCRIPT_NAME vs REQUEST_URI
... The filename of the currently executing script, relative to the document root. For instance, $_SERVER['PHP_SELF'] in a script at the address http://example.com/test.php/foo.bar would be /test.php/foo.bar. The __FILE__ constant contains the full path and filename of the current (i.e. included) file...
How to find/remove unused dependencies in Gradle
...ime scoped
Service providers (JAR files containing META-INF/services) like
mysql-connector-java are moved to runtime if there isn't any provable
compile-time reference
Dependencies are moved to the highest source set configuration
possible. For example, 'junit' is relocated to testCompile unless
the...
How to find all tables that have foreign keys that reference particular table.column and have values
...
For what kind of DB is this useful? MySql?
– Cirelli94
Jan 9 '18 at 10:56
...
How to add images to README.md on GitHub?
...ich for me is just the name of the image file because I have everything in root). I had been maintaining 2 copies of the README.md, one for local installation in /usr/share/projectname/docs, and one for github. Now, I can just use the same README.md for both since the image filenames work fine in bo...
How do I create a URL shortener?
...Take an auto-generated, unique numerical key (the auto-incremented id of a MySQL table for example).
For this example, I will use 12510 (125 with a base of 10).
Now you have to convert 12510 to X62 (base 62).
12510 = 2×621 + 1×620 = [2,1]
This requires the use of integer division and modulo. A ...
What's the difference between HEAD^ and HEAD~ in Git?
... / ],
F => [ qw/ I J / ],
);
sub postorder {
my($root,$hash) = @_;
my @parents = @{ $parents{$root} || [] };
postorder($_, $hash) for @parents;
return if $sha1{$root};
@parents = map "-p $sha1{$_}", @parents;
chomp($sha1{$root} = `git commit-tree @parents -m "$roo...
How do I create a self-signed certificate for code signing on Windows?
...tificates MMC snapin, but from the command line:
certutil -user -addstore Root MyCA.cer
Creating a code-signing certificate (SPC)
makecert -pe -n "CN=My SPC" -a sha256 -cy end ^
-sky signature ^
-ic MyCA.cer -iv MyCA.pvk ^
-sv MySPC.pvk MySPC.cer
It is pretty much th...