Would you play a multiplayer game if you discovered other people are cheating? According to a survey by Irdeto, 60% of online games were negatively impacted by cheaters, and 77% of players said they would stop playing a multiplayer game if they think opponents are cheating. Player churn grows as cheating grows.

Stopping this is therefore essential if you want to build and develop your community, which is essential to success for today’s gaming companies. This session at Percona Live ONLINE was presented by Yahav Biran, specialist solutions architect, gaming technologies at Amazon Web Services, and Yoav Eilat, Senior Product Manager at Amazon Web Services, presented a talk and demonstration about anti-cheating tools in gaming based on using automation and machine learning (ML).

Yoav notes that while people might think of ML in terms of text or images, but: …

Percona engineers often need to analyze and review complex SQL database queries. Good formatting can make these SQL queries much easier to understand and work with. Without clear formatting, queries can become confusing and hard to debug.

Online query formatting services provide one set of solutions. Examples are Code Beautify, FreeFormatter, and sqlformat.org. However, many users are not comfortable sharing their queries with third-party services, especially if your SQL code contains confidential information.

This article examines alternatives to online tools for SQL query formatting tools that have been successfully used by Percona engineers. These solutions come in different types:

1. Plug-ins to your code editor or …

Working on a weekend project,  I became familiar with the SQL keyword “LATERAL”, which I had not used before because it was only introduced recently in MySQL 8.0.14,  so I wanted to share how it can be used.

Some references on this topic:

Lateral Derived Tables

LATERAL Derived Tables in MySQL 8.0

The keyword “LATERAL” comes into play when you work with derived tables. The derived tables have been available in MySQL for a long time, and schematically they look like this:

SELECT t1.foo, t2.bar FROM t1, (SELECT bar FROM table2 WHERE <condition> ) t2 WHERE t1.id=t2.id;

The table “

(SELECT bar FROM table1 …

I will try to make it short and clear: if you are writing SQL queries with “NOT IN” like
SELECT … WHERE x NOT IN (SELECT y FROM …)
you have to be sure to first understand what happens when “x” or “y” are NULL: it might not be what you want!…

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Introduction In this article, we are going to see how the SQL EXISTS operator works and when you should use it. Although the EXISTS operator has been available since SQL:86, the very first edition of the SQL Standard, I found that there are still many application developers who don’t realize how powerful SQL subquery expressions really are when it comes to filtering a given table based on a condition evaluated on a different table. Database table model Let’s assume we have the following two tables in our database, that form a one-to-many... Read More

The post SQL EXISTS and NOT EXISTS appeared first on Vlad Mihalcea.

In MySQL 8.0.1, we introduced support for recursive common table expressions (CTE). There are quite a few blog entries showcasing the feature, starting from this one, and there is also a complete documentation. Today, I would like to present a solution to a problem which nearly everybody meets when writing queries with recursive CTE’s: when infinite recursion happens, how to debug ?…

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In MySQL 8.0.17, we made an observation in the well-known TPC-H benchmark for one particular query. The query was executing 20% faster than in MySQL 8.0.16. This improvement is because of the “antijoin” optimization which I implemented. Here is its short mention in the release notes:

“The optimizer now transforms a WHERE condition having NOT IN (subquery), NOT EXISTS (subquery), IN (subquery) IS NOT TRUE, or EXISTS (subquery) IS NOT TRUE internally into an antijoin, thus removing the subquery.”…

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Introduction In this article, we are going to see how a CROSS JOIN works, and we will also make use of this SQL join type to build a poker card game. Database table model For our poker card game application, we have created the ranks and suits database tables: The ranks table defines the ranking of cards, as well as the name and symbol used for each card rank: The suits table describes the four possible categories used by the French playing cards: Cartesian product In the set theory, the Cartesian product... Read More

The post A beginner’s guide to SQL CROSS JOIN appeared first on Vlad Mihalcea.

SQL UPPER function is used for converting all the characters in the source string to Uppercase characters. If any number is present in the string, then it remains unaffected. SQL UPPER() function converts a string to the upper-case.

SQL upper() Function

Suppose you have the online shopping website. Customers visit the website and provide the necessary information while creating the login account.

Each customer provides few compulsory information such as first name, last name, phone number, email address, and residential address.

Each customer is different, so you cannot expect the similar format for all inputs.

For example, you get a following entries in an SQL table.

We do not see all words following the consistent pattern.

It does not look good as well if you have to share the report daily to higher management for all newly enrolled customers.

The SQL UPPER …

AWS is the #1 cloud provider for open-source database hosting, and the go-to cloud for MySQL deployments. As organizations continue to migrate to the cloud, it’s important to get in front of performance issues, such as high latency, low throughput, and replication lag with higher distances between your users and cloud infrastructure. While many AWS users default to their managed database solution, Amazon RDS, there are alternatives available that can improve your MySQL performance on AWS through advanced customization options and unlimited EC2 instance type support. ScaleGrid offers a compelling alternative to hosting MySQL on AWS that offers better performance, more control, and no cloud vendor lock-in and the same price as Amazon RDS. In this post, we compare the performance of MySQL Amazon RDS …