St Louis
-
9 min readConcurrency and isolation levels are essential aspects of managing transactions in PostgreSQL. Concurrency refers to multiple transactions executing simultaneously in the database, while isolation levels determine the level of isolation between these concurrent transactions.To handle concurrency and isolation levels effectively in PostgreSQL transactions, consider the following points:Concurrency Control: PostgreSQL uses a multi-version concurrency control (MVCC) approach to handle concurrency.
-
7 min readA list in Haskell is a collection or sequence of elements of the same type. It can be used to store and manipulate multiple values. Lists are particularly useful in functional programming as they enable recursion and pattern matching.To create a list in Haskell, you can use square brackets. Elements are separated by commas. For example, the list of integers [1, 2, 3, 4] contains four elements.Lists can be created using a range of values. You can specify a range using two dots '..
-
9 min readTo launch Zabbix server on Cloudways, you need to follow the steps mentioned below:Log in to your Cloudways account.From the Cloudways dashboard, click on "Applications" in the top menu bar.Click on the "Add Application" button.Select your desired cloud provider (e.g., AWS, Google Cloud, DigitalOcean) and server size.Choose the PHP version and select "Zabbix" from the drop-down menu under the "Components" section.
-
7 min readTablespaces in PostgreSQL are used to organize the physical storage of database objects, such as tables, indexes, and other database files. They allow for flexibility in managing disk space and distributing storage across multiple storage devices.To create a new tablespace in PostgreSQL, you can use the CREATE TABLESPACE command followed by specifying the name of the tablespace and the location where the data files will be stored.
-
6 min readIn Haskell, performing input/output (I/O) is achieved using the IO monad and a set of functions provided by the standard library. The IO monad represents computations that perform I/O operations. Here is an overview of the primary techniques for I/O in Haskell:putStrLn: It is used to print a string to the standard output. Example: putStrLn "Hello, World!" getLine: This function reads a line of input from the user, returning it as a string.
-
10 min readPerforming online schema changes in PostgreSQL is a way to modify the database schema without obstructing concurrent access to the database. This method allows data manipulation and schema changes to occur simultaneously, ensuring minimal downtime for applications.To perform online schema changes in PostgreSQL, you have a few options:Using the pg_repack extension: pg_repack is an extension that allows you to reorganize tables without blocking concurrent operations.
-
6 min readPattern matching is a powerful feature in Haskell that allows you to deconstruct data structures and extract values. It is used to define functions that behave differently based on the shape or contents of the input.Here is a general syntax for pattern matching in Haskell: functionName :: DataType -> ReturnType functionName pattern1 = result1 functionName pattern2 = result2 ...
-
9 min readPhalcon is a high-performance PHP framework that allows developers to build web applications faster and efficiently. In this tutorial, we will guide you on how to deploy a Phalcon application on GoDaddy, a popular web hosting service.Check Server Requirements: Make sure your GoDaddy hosting plan supports PHP. Ensure that the PHP version meets Phalcon's requirements (e.g., version 7 or above). Set up a GoDaddy Account: Register and purchase a suitable hosting plan on GoDaddy.
-
9 min readTo deploy Yii on Vultr, you can follow these steps:Sign up for a Vultr account: Go to the Vultr website (https://www.vultr.com/) and create an account if you don't have one already. Provide the necessary details and complete the registration process. Create a new server: After logging into your Vultr account, click on the "Servers" tab and then click on the blue "+ Deploy New Server" button. Select the desired server location, server type, operating system, and server size.
-
7 min readLogical replication in PostgreSQL allows you to replicate selected tables or parts of tables from one PostgreSQL database to another. It provides a flexible and powerful way to create replication setups for various use cases.To implement logical replication in PostgreSQL, you need to follow these steps:Set up the publisher database: The database from which the data will be replicated is called the publisher.
-
5 min readTo write a simple "Hello World" program in Haskell, follow these steps:Open a text editor or an Integrated Development Environment (IDE) that supports Haskell programming. Create a new Haskell source file with a .hs extension, such as helloWorld.hs. In the newly created file, start by defining a main function. The main function is the entry point for any Haskell program. Inside the main function, use the putStrLn function to print the string "Hello, World!" to the console.