For a table with billions of records, optimizing SQL query is crucial. The main problem with the query is that it applies functions (YEAR, MONTH, DATEFROMPARTS) to the ORDERDATE column within the GROUP BY clause. This forces the database to perform a calculation for every single row before it can group them, preventing the efficient…
Whether you’re optimizing performance or simplifying your queries, these SQL tips from mietwood.com will help you write cleaner, faster, and more efficient code. SQL is the backbone of data-driven decision-making, and mastering it can dramatically improve how you interact with databases. Whether you’re a seasoned developer or just starting out, writing efficient, readable, and scalable…
A CTE Common Table Expression is a temporary result set that you can reference within a SELECT, INSERT, UPDATE, or DELETE statement. A recursive CTE in SQL Server is a special kind of CTE that refers to itself. It’s useful for tasks like generating sequences like dates or numbers or traversing hierarchical data, e.g., org charts, folder structures etc. A recursive CTE in SQL Server consists…
To optimize your queries for better performance and a lighter load on the database, consider the following 10 Tips How To Make SQL Lighter. SQL queries can be heavy and slow for various reasons, including inefficient data retrieval, poor indexing, and improper joins. Reduce records in reference. Instead of query 1 which is quite heavy…
Python’s powerful date and time functions using the datetime and pandas libraries gives you a robust date table ready for Power BI and other business intelligence and analytical tools. Python for analysts most important datetime functions. Mastering Date and Time Functions in Python for Power BI Date Tables When working with Power BI, a well-structured…
The post will explore two methods for creating a moving average in SQL Server. The older methods using linking and correlation queries and a new using widows functions in SQL Server. Moving average in SQL Post is based on: Calculate a Moving Average with T-SQL Windowing Functions Indexing moving average – old approach Statistics Another…
Advanced Programming in SQL and Python – the course for business analysts – this course aims to equip students with advanced skills in SQL and Python, focusing on their application in business analytics. Through seven mini analytical case studies, students will gain hands-on experience in solving real-world business problems. Course Structure: Week 1-2: Introduction and…
Normalization aims to eliminate redundancy and enforce data integrity by organizing data into logical, dependency-driven forms.
How To Set The First Day of Week DATEFIRST – SET DATEFIRST = 1 sets the first day of the week to Monday. In SQL Server, the first day of the week can be set to any day from 1 (Monday) to 7 (Sunday). This setting affects the output of date-related functions like DATEPART and…
The PIVOT operator in SQL Server is an advanced relational operator that helps transforming and reorganizing data in a tabular format, enhancing analytical capabilities. It enables the conversion of unique data from rows into columns, thereby allowing for a more streamlined presentation of aggregated data. This transformation is particularly beneficial in generating cross-tabular reports where…