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COUNT(*) vs. COUNT(1) vs. COUNT(pk): which is better? [duplicate]
...T(field) or COUNT(*), and stick with it consistently, and if your database allows COUNT(tableHere) or COUNT(tableHere.*), use that.
In short, don't use COUNT(1) for anything. It's a one-trick pony, which rarely does what you want, and in those rare cases is equivalent to count(*)
Use count(*) fo...
Are members of a C++ struct initialized to 0 by default?
...hot s; // receives no initialization
Snapshot s = {}; // value initializes all members
The second will make all members zero, the first leaves them at unspecified values. Note that it is recursive:
struct Parent { Snapshot s; };
Parent p; // receives no initialization
Parent p = {}; // value init...
Why should we NOT use sys.setdefaultencoding(“utf-8”) in a py script?
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As per the documentation: This allows you to switch from the default ASCII to other encodings such as UTF-8, which the Python runtime will use whenever it has to decode a string buffer to unicode.
This function is only available at Python start-up time,...
Output of git branch in tree like fashion
...nclosed-message-display-tweaks merged in
(x) experiment merged in (only locally)
NOTE: working directory contains modified files
git-wtf shows you:
How your branch relates to the remote repo, if it's a tracking branch.
How your branch relates to non-feature ("version") branches, if i...
How are virtual functions and vtable implemented?
We all know what virtual functions are in C++, but how are they implemented at a deep level?
12 Answers
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Copy the entire contents of a directory in C#
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Much easier
//Now Create all of the directories
foreach (string dirPath in Directory.GetDirectories(SourcePath, "*",
SearchOption.AllDirectories))
Directory.CreateDirectory(dirPath.Replace(SourcePath, DestinationPath));
//Copy all the files...
Comparison of Lucene Analyzers
...text. For example, KeywordAnalyzer you mentioned doesn't split the text at all and takes all the field as a single token. At the same time, StandardAnalyzer (and most other analyzers) use spaces and punctuation as a split points. For example, for phrase "I am very happy" it will produce list ["i", "...
How to install PostgreSQL's pg gem on Ubuntu?
I'm trying to install PostgreSQL's pg gem for Ruby.
19 Answers
19
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Remove all elements contained in another array
I am looking for an efficient way to remove all elements from a javascript array if they are present in another array.
14 A...
Command-line svn for Windows?
...the distribution but this should not be a problem in most cases.
Once installed you might need to add the folder containing svn.exe to the system PATH as described here so that it is available in your console. To check if it was already added by the installer open a new console and type echo %PATH%...