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What is Virtuoso? Virtuoso is a powerful and flexible database system. It doesn’t just work with tables like regular databases but also supports other data types like graphs, XML, and RDF stores. This makes it great for big projects like building smart web systems or combining large amounts of data.Virtuoso is built for complex systems that need to handle lots of data, work across multiple locations, and grow easily. It follows strict data rules (ACID), has many tools for developers, and offers advanced ways to share and copy data.You can store data in tables or as graphs, and it works ... Read More
Secure Copy Protocol (scp) helps to securely transfer files between hosts on a network. It relies on SSH (secure shell) using SFTP protocol to create a secure connection and encrypt the data during transit whether it is a single file or whole directory. scp uses the same authentication as SSH and provides the same security as a login session. It'll prompt for password or passphrases, if required. If SSH keys are configured between local and remote systems for the involved user(s), scp can run without any prompts to the user. This article will show you how you can ... Read More
VirtualBox is an open-source, cross-platform virtualization tool by Oracle which allows us to create and run multiple operating systems simultaneously on a single physical machine. As a Type-2 Hypervisor, VirtualBox is installed on top of an operating system such as Windows, Linux or Mac and provides both headless interface and GUI (Graphical User Interface) for creating and managing virtual machines. Installing VirtualBox Step-by-step process for installing VirtualBox on a CentOS 9 machine is as follows: Initially, check if your system supports virtualization with the command below: $ lscpu | grep -i virtualization Virtualization type: full $ In case, there’s ... Read More
On all Linux-based systems, PATH is the name of a crucial environment variable which is used by shell to look for executable files before running any command. The PATH variable contains a list of directories where different system and user-based programs are available. This variable sometimes needs to be updated to include additional custom directories, to allow running executables from new location without specifying the absolute path of the executable (or first changing to its parent directory). For example, instead of specifying the absolute path for Python like /usr/bin/python3, you can simply write python3 because /usr/bin is part of the ... Read More
In any Linux terminal, you usually get a prompt to type commands and get their outputs. For some commands and scripts, you may need inputs which are usually provided by the user by typing on the terminal. For normal commands or text inputs, we can see whatever is typed on the terminal. But there are some cases where we don't want to display these input text on screen for security reasons, like preventing any sensitive information such as passwords, keys or personal data from getting exposed. Linux terminal allows us to prevent printing of typed characters on screen for this ... Read More
DNS is the backbone of modern Internet infrastructure. DNS stands for Domain Name System which is a system that translates domain names into IP addresses. There are different types of DNS queries and hierarchy of DNS servers that resolve DNS queries. Like any query, DNS queries also introduces some latency which could affect application performance and end-user satisfaction, if the delay adds up significantly. What is DNS Caching? DNS caching is a critical mechanism that improves network performance and reduces unnecessary network traffic. By storing previously resolved domain names locally, DNS cache helps speed up web browsing, network applications, and ... Read More
In this article, we will learn to deselect all cells in a JTable in Java. The JTable component is a powerful tool for displaying tabular data when working with Java Swing applications. Sometimes, you may want to deselect all selected cells in a JTable programmatically. Why Deselecting Cells in JTable is Important In certain scenarios, such as resetting form fields, implementing "Clear Selection" buttons, or preparing the table for a fresh data display, you need to clear the selection in a JTable. This improves user experience and ensures the application behaves as expected. Deselecting All Cells in JTable Following are the ... Read More
In this article, we will learn the Collectors.toCollection() method in Java, an essential tool for collecting elements into a specific type of collection, such as a List, Set, or any other collection type. Java 8 introduced a new, powerful feature called Streams, which enables functional-style programming to process sequences of elements. One of the key utilities in the Streams API is the Collectors class. What is the Collectors.toCollection() Method? The Collectors.toCollection() method is a static method in the Collectors class that allows you to collect elements from a stream into a custom collection. public static Collector toCollection(Supplier collectionFactory) Here ... Read More
In this article, we will learn to convert the first character to uppercase in a sentence in Java, converting the first character of each word or sentence to uppercase is a common text manipulation task. It ensures proper formatting, which is particularly useful in text processing, string parsing, and user interface applications. Approaches to convert first character uppercase in a sentence Following are the two approaches to converting the first character of a sentence to uppercase − Using String Manipulation and Character Methods Using Regular Expressions with the Matcher() Method Using ... Read More
A read-only map in Java is a type of Map that cannot be modified after it has been created. This means that once the map has been set to be read-only, we cannot add, remove, or update any of the key-value pairs.Converting a Map to a read only map We can convert a mutable map to an immutable map, a read-only map using the Collections.unmodifiableMap() method. This method provides a way to make sure that the map cannot be modified once it has been wrapped in this method. Following are the steps to convert a Map to a read-only map ... Read More