The latest from the MySQL community

I’ve been doing a lot of database stuff lately, and not much PHP, so when I returned to make my first Laravel project for a while, I had to check the docs to remind myself how some of this works. I noticed that the default approach to database credentials is still to use separate credentials for the host, port, and other variables. I’m using Aiven databases (because I work there and managed databases are great for demo apps as well as real ones!) which supply connection strings, but Laravel supports these too.

For MySQL, the database connection string from Aiven is in the format:

mysql://username:password@hostname:port/dbname

You can remove the configuration for DB_* and instead use the variable DATABASE_URL with the full string.

Pro-tip: Laravel’s built …

Introduction Welcome to a new issue of the High-Performance Java Persistence Newsletter in which we share articles, videos, workshops, and StackOverflow answers that are very relevant to any developer who interacts with a database system using Java. Articles From version 2.12, Percona PMM uses Victoria Metrics instead of Prometheus. Victoria Metrics provides better disk I/0 utilization and less memory usage. For more details about this change and its benefits, check out this article. By default, the MySQL JDBC Driver only emulates prepared statements. If you wonder whether server-side prepared statements perform better... Read More

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Percona Live Online Agenda Slot: Tue 20 Oct • New York 6:00 p.m. • London 11:00 p.m. • New Delhi 3:30 a.m. • Singapore 6:00 a.m.

Abstract

MySQL’s sweet spot is known to be online transaction processing (OLTP), and it can support a very high load of short transactions. Many users will also want to run analytical queries (OLAP) on their MySQL data. Often they achieve this by exporting their data to another database system that is tailored for analytical queries. However, this introduces overhead and delay that can be avoided by running your analytical queries directly in your MySQL database.

This presentation will discuss how you can tune your complex analytical queries to achieve better performance with MySQL. We will look at some of the queries from the well-known TPC-H/DBT-3 benchmark, and show how we can improve the performance of …

Creating the database for an application is simple and easy. However, database script management gets complicated in a hurry when you need to support multiple versions, work with multiple teams, and apply the same changes to multiple types of databases. 

One open-source tool that helps teams track, version, and deploy database schema changes is Liquibase. It executes database scripts sequentially, allows for the automatic creation and execution of rollback scripts for failed updates, and provides an easy way to use the same scripts and apply them to different types of databases. To illustrate how Liquibase works, here’s an example using PostgreSQL.   

System set up:

• Download the latest version of Liquibase. 
• …

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: …

Introduction Welcome to a new issue of the Java and Database newsletter in which we share articles, announcements, and StackOverflow answers that are very relevant to any developer who interacts with a database system from Java. Articles Since version 13, Java now supports multiline string literals via the Text Blocks feature. To see how much more readable are SQL or JPQL queries, JSON, HTML, and XML string literals when using Text Blocks, then you should definitely read this article, When writing SQL queries with the NOT IN query expression, you need to... Read More

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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

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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

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Introduction In this article, we are going to see how a deadlock can occur in a relational database system, and how Oracle, SQL Server, PostgreSQL, or MySQL recover from a deadlock situation. Database locking Relational database systems use various locks to guarantee transaction ACID properties. For instance, no matter what relational database system you are using, locks will always be acquired when modifying (e.g., UPDATE or DELETE) a certain table record. Without locking a row that was modified by a currently running transaction, Atomicity would be compromised. Using locking for controlling access... Read More

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Introduction Ever wanted to connect to a relational database using Java and didn’t know which JDBC Driver Maven dependency to use? If so, this article is surely going to help you from now on. Oracle Since September 2019, the Oracle JDBC Driver is available on Maven Central. For JDK 10 and 11, use the following Maven dependency: For JDK 8, use the ojdbc8 artifact instead: For more details about the proper version to use, check out the following Maven Central link. MySQL The MySQL Driver is available on Maven Central, so just... Read More

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