This post is a little long, please bear with me as after the intro, you can skip to the essential.In the last weeks / months, I have been working on understanding / improving MySQL startup with many tables.  I already wrote three posts on the subject, they are listed below.  In this post, I focus on describing the startup phase InnoDB Tablespace Duplicate Check (Duplicate Check for

In the last weeks / months, I have been working on understanding / improving MySQL startup with many tables.  I already wrote two posts on the subject, the links are below.  So far, I did not share what brought my attention to this, and it is the subject of this post.  Also, and because it is related, I come back to the optimization / contribution I already made on

Explore the powerful features of Aurora Serverless V2 for MySQL in this informative blog series. Learn about read-only scaling, parameter support, and cost performance. Compare costs between Provisioned Aurora and Aurora Serverless V2. Discover key takeaways for optimizing your MySQL deployment on the cloud. Read now!

1. Read-only Scaling
   1. Failover replicas
   2. …

Sometimes, the MySQL Optimizer chooses a wrong plan, and a query that should execute in less than 0.1 second ends-up running for 12 minutes !  This is not a new problem: bugs about this can be traced back to 2014, and a blog post on the subject dates of 2015.  But even if this is old news, because this problem recently came to my attention, it is a problem worth writing on.

This

Introduction In this article, we are going to see how we can enable the MySQL JDBC Driver Statement Caching mechanism, which, unfortunately, is not enabled by default. No matter what data access framework you are using, you still need to configure the JDBC Driver if you want to get the most out of the MySQL database engine. MySQL JDBC client-side PreparedStatement As I explained in this article, by default, the MySQL JDBC Driver emulates prepared statements. So, no matter if you are executing a plain Statement or a PreparedStatement, the SQL statement... Read More

The post MySQL JDBC Statement Caching appeared first on Vlad Mihalcea.

In MySQL 8.0.16 the optimizer has improved again! Comparisons of columns of numeric types with constant values are checked and folded or removed for invalid or out-of-rage values. The goal is to speed up query execution.

Since MySQL 5.7 one can put indexes on expressions, aka functional indexes, using generated columns. Basically you first need to use the generated column to define the functional expression, then indexed this column.

Quite useful when dealing with JSON functions, you can find an example here and the documentation there.

Starting with MySQL 8.0.13 we have now an easiest way to create functional indexes (or functional key parts as mentioned in the documentation) \o/

Let’s see how with a quick practical example.

A Guest Post from Jordan Raine, Clio

Jordan Raine is a staff software developer at Clio, the leading provider of legal practice management, client relationship management, and client intake software. Clio is dedicated to helping lawyers meet client needs and run efficient, profitable practices. Jordan wrote this post to help mySQL developers save time/effort and ultimately improve their customers' experience. 

Unlike most code a developer writes, writing SQL only requires us to describe what data we want and not how to get it. When given a query like SELECT id, author_id FROM posts WHERE author_id = 123 ORDER BY id, you needn’t concern yourself with what indexes are used (if any), what type of sort is used, or any other number of implementation details. Instead, the query optimizer handles this for you. This keeps SQL concise and …

Narrowing down which queries to optimize is a step in database administration that is often skipped - however it shouldn't be!  

Why is selecting the right queries to optimize so important? There are several reasons. 

Penny-Wise, Pound-Foolish  Look at the forest, not just the trees, and optimize globally, not locally. If you’re optimizing a query that never causes a user-visible problem, doesn’t impact other queries, and doesn’t significantly load servers, you might be “optimizing” things that don’t matter, spending more money than you save. Your time has value, too! Keep in mind, too, that optimizing a query that generates only 1% of the database’s overall load will not be a significant benefit to the bottom line.   Whack-A-Mole Queries It’s very common to  find a slow query in a log file, try re-executing it and  then find that it is fast. …

Join Percona’s Chief Evangelist, Colin Charles as he presents Differences Between MariaDB and MySQL on Wednesday, January 24, 2018, at 7:00 am PST (UTC -8) / 10:00 am EST (UTC -5).

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Tags: MariaDB, MySQL, Percona Server for MySQL, DBA, SysAdmin, DevOps
Experience Level: Novice

MariaDB and MySQL. Are they syntactically similar? Where do these two query languages differ? Why would I use one over the other?

MariaDB is on the path of gradually diverging from MySQL. One obvious example is the internal data …