In PostgreSQL, replication mechanisms—whether physical or logical—rely heavily on the Write-Ahead Logging (WAL) system. WAL serves as a fundamental component to ensure data consistency, durability, and to support replication processes. This article explains how WAL works in PostgreSQL, including its role in replication, file management, and system recovery. What is Write-Ahead Logging (WAL)? Write-Ahead Logging …

In PostgreSQL, the Write-Ahead Log (WAL) is a critical part of ensuring data durability and consistency. WAL files store all changes made to the database, and they are used for replication, point-in-time recovery (PITR), and crash recovery. Understanding how to find the current WAL file and how to switch to a new WAL file can …

Introduction PostgreSQL is a robust, open-source relational database management system that offers advanced features for data storage, processing, and retrieval. One of the key components of PostgreSQL’s security model is the GRANT statement. This statement allows database administrators to control access to database objects like tables, views, sequences, and functions by assigning specific privileges to …

PostgreSQL is a powerful and widely-used open-source relational database management system (RDBMS) known for its robustness, scalability, and performance. At its core, PostgreSQL uses Multiversion Concurrency Control (MVCC), a technique that allows multiple transactions to occur simultaneously without interfering with each other. While MVCC enhances database performance by enabling high concurrency, it also creates a …

Replication is a key component of database management systems (DBMS) that allows for the duplication of data across multiple systems. In PostgreSQL, replication ensures that data from one server (the primary) is mirrored to one or more other servers (the standby). PostgreSQL offers two primary methods of replication: physical replication and logical replication. Each method …

Logical replication is an advanced feature in PostgreSQL that allows the replication of database changes at a logical level, meaning it replicates the changes made to data rather than replicating the physical data itself. Introduced in PostgreSQL 10, logical replication offers a flexible and efficient way to manage data across different PostgreSQL instances. This contrasts …

PostgreSQL is renowned for its flexibility and robustness in handling high-availability configurations, and replication is one of the key features that ensures data is consistent and available across multiple nodes. One important aspect of PostgreSQL replication is replication slots, a feature that was introduced in PostgreSQL 9.4. Replication slots provide a mechanism to ensure that …

The ANALYZE command in PostgreSQL is used to collect statistics about the contents of tables and indexes. These statistics are essential for the query planner to generate efficient query execution plans, improving the overall performance of database queries. By gathering data on the distribution of values in each column, PostgreSQL can optimize how it executes …

If you often work with PostgreSQL queries, you know that sometimes the raw output can be difficult to read, especially when you’re dealing with long queries or large datasets. Fortunately, PostgreSQL provides several ways to format and organize your query results for better readability. In this article, we will explore five practical methods to make …

The SET command in PostgreSQL is used to configure session-level parameters. Unlike global configuration changes, which affect the entire PostgreSQL server and require administrative access, the SET command allows users to modify settings that are valid only for the current session. This command is extremely useful for temporary adjustments or tuning parameters for specific queries …