SQL, the language that reigns supreme in the world of relational databases, offers an array of features to manipulate and analyze data effectively. A notably powerful feature among them is the SQL window functions. Window functions enable computations across a… Read More »Comprehensive Guide to SQL Window Functions
Introduction The dynamics of database management prioritize efficient data retrieval as a key performance index. Herein lies the significance of database statistics, which provide a snapshot of database content like row counts in a table or value distributions within a… Read More »What is the Importance of Database Statistics in Query Optimization?
Introduction A phantom read is a scenario that occurs in a database when a transaction re-executes a query and finds that another committed transaction has added or removed rows that weren’t there previously. This anomaly can lead to inconsistencies in… Read More »What is a Phantom Read Anomaly?
Non-Repeatable Read is a database anomaly that occurs in the context of transactions, which are sequences of database operations that should behave as single, indivisible units of work. Non-Repeatable Read happens when a transaction reads the same row twice, and gets different data each time. This is usually due to another transaction modifying the data after the first read. In this post, we look at this concept in detail and techniques to address this.
What is a Dirty Read By definition, a dirty read occurs when a transaction reads data from another transaction that has not yet been committed. The “dirty” moniker refers to the potential unstable state of the data, as it is… Read More »How do ‘Dirty Reads’ Impact Database Consistency?
Database isolation is a property that defines how and when the changes made by one operation become visible to other concurrent operations. Isolation is one of the ACID (Atomicity, Consistency, Isolation, Durability) properties.
In this post, we will look at 4 standard isolation levels along with some database-specific ones.
ACID is a fundamental concept in database systems, standing for Atomicity, Consistency, Isolation, and Durability. These properties ensure reliable processing of database transactions. ACID Properties of Database Systems Atomicity Atomicity ensures that a transaction is treated as a single, indivisible… Read More »What is ACID in database systems?
Introduction to EXPLAIN Plains An EXPLAIN plan, often simply called an “explain”, is a tool in SQL-based database systems like PostgreSQL that provides information about how a database will execute a given query. By inputting a SQL query to the… Read More »What is an EXPLAIN Plan? How is it interpreted?
As a PostgreSQL developer, the optimization of your SQL queries is a vital task that can greatly enhance the performance of your database. This is where the commands EXPLAIN and EXPLAIN ANALYZE come into play. They provide detailed insights into… Read More »Unleashing the Power of EXPLAIN in PostgreSQL
Indexing is a powerful technique in relational databases that enhances query performance by minimizing the time it takes to search and retrieve data. It’s similar to the way you use an index in a book to quickly find the page containing the information you seek. In this blog post, we’ll dive into the world of indexing, focusing on how it works in relational databases like PostgreSQL, and explore the benefits and trade-offs involved.