Tutorial by Topics: i

In this topic Spark Users can find different configurations of Spark SQL, which is the most used component of Apache Spark framework.

If you commit sensitive data, such as a password or SSH key into a Git repository, you can remove it from the history. To entirely remove unwanted files from a repository's history you can use either the git filter-branch command or the BFG Repo-Cleaner. Tell your collaborators to rebase, ...

Garbage Collection (GC) is a way of automatically reclaiming memory that is occupied by objects that are no longer needed by a program. This is in contrast with manual memory management where the programmer explicitly specifies which objects should be deallocated and returned to memory. Good GC-s...

In this topic I would like to mention all possible global variables which can be used in Apex code. Like [UserInfo Class][1]. I suggest we just list a global classes/variables and links. If you know about a global class/variable but can't find a documentation, please provide as much informati...

This example shows how to create a ViewModel and a View within the MVVM pattern and WPF, and how to bind the two together, so that each is updated whenever the other is changed.

A column is NULL when it has no value, regardless of the data type of that column. A column should never be compared to NULL using this syntax a = NULL as the result would be UNKNOWN. Instead use a IS NULL or a IS NOT NULL conditions. NULL is not equal to NULL. To compare two expressions where null...

A soon as application have several pages/screens, a way of navigating among them is needed. With UWP applications, the navigation is handled by the [Frame][1] control. It displays [Page][2] instances, support the navigation to new pages and keep an history both for backward and forward navigation ...

C++/CLI is a Microsoft-specific dialect of C++ which interoperates well with .NET. Originally, it was envisioned as the "most powerful" of .NET languages and included designer support for WinForms applications. However, new development on C++/CLI has all but ceased, and Microsoft now ...

This section provides an overview of what mqtt is, and why a developer might want to use it. It should also mention any large subjects within mqtt, and link out to the related topics. Since the Documentation for mqtt is new, you may need to create initial versions of those related topics.

Input and Output in scheme is usually handled trough ports. A port is a data structure which is used to interact with the world outside Scheme. A Port isn't limited to files but can be used to read/write to sockets. In some ways, the port object is some kind of universal object that can not onl...

A Pair is one of the most basic data type in scheme. It is also usually called cons cells.

COMMMENT main purpose is to define or change a comment on database object. Only a single comment(string) can be given on any database object.COMMENT will help us to know what for the particular database object has been defined whats its actual purpose is. The rule for COMMENT ON ROLE is that you m...

This section provides an overview of what automation is, and why a developer might want to use it. It should also mention any large subjects within automation, and link out to the related topics. Since the Documentation for automation is new, you may need to create initial versions of those rel...

The data.table package has undergone a number of changes and innovations over time. Here are some potential pitfalls that can help users looking at legacy code or reviewing old blog posts.

A notorious common question is "how to send notifications from device to device", sadly the answer is: you can't. FCM needs to be triggered in order to send push notifications. That can be done in 3 different ways: Directly in the Firebase web console Setting a Firebase Functions li...

C++, like C, has a long and varied history regarding compilation workflows and build processes. Today, C++ has various popular build systems that are used to compile programs, sometimes for multiple platforms within one build system. Here, a few build systems will be reviewed and analyzed. Current...