Faster Pagination in Mysql – Why Order By With Limit and Offset is Slow?

Queries with LIMITs and OFFSETs are common in application that require pagination and in some cases might work well for a while. In many cases though, they become slow and painful once the OFFSET has a high value. Why OFFSET is so slow? Well, in most cases, low offset queries are not slow. The problem… Continue reading Faster Pagination in Mysql – Why Order By With Limit and Offset is Slow?

MySQL utf8 vs utf8mb4 – What’s the difference between utf8 and utf8mb4?

UTF8 VS UTF8MB4 – What’s the difference? You’re getting a support call from an IT administrator in a tech company saying some of his critical data can’t be saved in the product you deployed at his servers a week ago. His users are seeing a general error from the application. About 30 of his 500… Continue reading MySQL utf8 vs utf8mb4 – What’s the difference between utf8 and utf8mb4?

Most popular databases in 2017 according to StackOverflow survey

The survey results from StackOverflow’s developers survey are already here, and we can now declare the most popular databases for 2017. Without further ado, let’s look into the results: So what can we learn from these results? The most popular database is MySQL, and not by far comes SQL Server. Almost half of the developers… Continue reading Most popular databases in 2017 according to StackOverflow survey

Select max, min, last row for each group in SQL without a subquery

In several RDBMS databases, including MySQL, subqueries are often one of the causes for performance issues. Therefore, we have an incentive to avoid them whenever we can and to find alternative ways to implement our requirements. One of the most popular uses for subselects in SQL is when one needs to fetch the first, last,… Continue reading Select max, min, last row for each group in SQL without a subquery

MySQL 5.7 vs MySQL 8.0 – What’s new in MySQL 8.0?

MySQL is arguably the most popular and common RDBMS. The last major release was MySQL 5.7 back in 2013. As of today, several development milestones were declared for MySQL v8.0, but there is no official release available yet. Even though there is no official software release to download and use yet, the list of features for MySQL 8.0 was… Continue reading MySQL 5.7 vs MySQL 8.0 – What’s new in MySQL 8.0?

Django vs SQLAlchemy – Which Python ORM is better?

What’s an ORM? Before going into the difference between Python’s ORM frameworks (Django and SQLAlchemy), let’s make sure we fully understand the use of ORM frameworks in general. ORM stands for Object Relational Mapping. Looking at each of these words will explain their use in the real world: Object – This part represents the objects and programming… Continue reading Django vs SQLAlchemy – Which Python ORM is better?