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What are the use cases for selecting CHAR over VARCHAR in SQL?
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The general rule is to pick CHAR if all rows will have close to the same length. Pick VARCHAR (or NVARCHAR) when the length varies significantly. CHAR may also be a bit faster because all the rows are of the same length.
It var...
Pass a data.frame column name to a function
I'm trying to write a function to accept a data.frame ( x ) and a column from it. The function performs some calculations on x and later returns another data.frame. I'm stuck on the best-practices method to pass the column name to the function.
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What use is find_package() if you need to specify CMAKE_MODULE_PATH anyway?
I'm trying to get a cross-plattform build system working using CMake. Now the software has a few dependencies. I compiled them myself and installed them on my system.
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Why Qt is misusing model/view terminology?
I think that the terminology used in Qt with model/view controls is flawed. On their explanation page they state, that they simplified the MVC to MV by merging View and Controller and they are giving the following picture:
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Why use pointers? [closed]
...s is a really basic question, but I've just started with some basic C++ programming after coding a few projects with high-level languages.
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How does lucene index documents?
...out Lucene; also I read the document in this link
( http://lucene.sourceforge.net/talks/pisa ).
4 Answers
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What is the difference between JSON and Object Literal Notation?
... me what is the main difference between a JavaScript object defined by using Object Literal Notation and JSON object ?
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App Inventor 2 上传文件和图片到服务器教程 · App Inventor 2 中文网
.navbar .nav-link .mdi, .navbar .dropdown-item .mdi { margin-right: 6px; opacity: .7; } 创建 Apps 文档 文档首页 内置块参考文档 组件参考文档 拓展参考文档 概念参考文档 IoT 参考文档 技术和其他指...
How do exceptions work (behind the scenes) in c++
I keep seeing people say that exceptions are slow, but I never see any proof. So, instead of asking if they are, I will ask how do exceptions work behind the scenes, so I can make decisions of when to use them and whether they are slow.
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How does LMAX's disruptor pattern work?
I am trying to understand the disruptor pattern . I have watched the InfoQ video and tried to read their paper. I understand there is a ring buffer involved, that it is initialized as an extremely large array to take advantage of cache locality, eliminate allocation of new memory.
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