(based on a conversation with a colleague, and a bit of Twitter)

A Conundrum

A developer colleague paged me with this:

mysql> select
UNIX_TIMESTAMP("2021-03-26 03:07:00" + INTERVAL 2 YEAR) -
UNIX_TIMESTAMP("2021-03-26 02:07:00" + INTERVAL 2 YEAR) as delta\G
delta: 420

It is obviously wrong, and weirdly so. It only works for “2 year”, not with other values:

mysql> select
UNIX_TIMESTAMP("2021-03-26 03:07:00" + INTERVAL 1-11 year_month) -
UNIX_TIMESTAMP("2021-03-26 02:07:00" + INTERVAL 1-11 year_month) as delta\G
delta: 3600

mysql> select
UNIX_TIMESTAMP("2021-03-26 03:07:00" + INTERVAL 1-12 year_month) -
UNIX_TIMESTAMP("2021-03-26 02:07:00" + INTERVAL 1-12 year_month) as delta\G
delta: 3600

mysql> select
UNIX_TIMESTAMP("2021-03-26 03:07:00" + INTERVAL 1-13 year_month) -
UNIX_TIMESTAMP("2021-03-26 …

MySQL installation security is something that should be on the  mind of every MySQL DBA. While we have discussed how you should take care of your MySQL security as a whole (take a look at some of our previous posts, specifically the MySQL security series Part One and Part Two), we haven’t  discussed specific security-related issues, including  those issues related to privileges. We do that here.

What are Privileges in MySQL?

Privileges in MySQL can be granted to accounts. If you grant account privileges in MySQL, you determine which operations the account can perform. Privileges can be granted to either databases or database objects (tables, indexes, views etc.) Privileges can also be dynamic or static. Static privileges …

Over the decades we have been reading the MySQL error log from the server system file, if there are any issues in MySQL or any unknown restart happened , generally we look at the mysql error log.

By default MySQL error log can be found in the default path /var/log/mysqld.log , or it can be explicitly configured using the variable log_error.

Few drawbacks using MySQL error log as FILE

• Possibility of missing genuine errors while reading lengthy information.
• Filtering of errors for the particular date and timeframes.
• Cannot provide the DB server access to developers because of fear of mishandling DB servers.

To overcome the above issues , from MySQL …

For MySQL, MyISAM and InnoDB storage engines are very popular. Currently, we are mostly using InnoDB engines for high reliability and high performance. Apart from those engines, we also have some other alternative engines and they have some nice features in them. In this blog, I am going to explain some of those engines, which I have listed below. 

• FEDERATED Storage Engine
• Merge or MRG_MyISAM Engine
• Blackhole Engine
• CSV Engine

FEDERATED Storage Engine Overview:

• FEDERATED Storage Engine allows you to access the data remotely without replication and cluster technologies. 
• Using the FEDERATED tables, you can scale your server load. Queries for the given table will be sent over the network to another MySQL instance. In this case, to scale the DB, you can use many MySQL instances without changing the application code.
• FEDERATED tables …

Have you ever wondered what it takes to complete Percona Server for MySQL (PS), Percona XtraDB Cluster (PXC), and Percona XtraBackup (PXB) releases? 

Let’s step back just a minute and talk about what Percona stands for. We believe we “stand on the shoulders of giants.” This means we respect our upstream sources and work to add value to the base products. Over time, new functionality is added. Much of this value-add was implemented on the 5.7 series and pulled forward to the 8.0 series. Each time we receive an upstream release, we must reapply these features to the release we receive. This process is what we call the Merge Process. …

HelloThis is a short guide on node js mysql connection example you will learn how to connect mysql database in node js we will help you to give example of how to use mysql in node js step by step explain mysql connection in node jsIn this example i will give you simple example of how to con

In the last post I covered some of the many reasons to migrate data from a spreadsheet to a database and now it is time to show how to do just that.  Moving data from a spreadsheet into MySQL can actually be pretty simple in many cases. Now I will not mislead you by telling you that all cases are easy but there is an easy way to make this migration.  And I highly recommend the following process when possible as it can save lots of time. More painful migrations will be covered in the future but this post is my favorite 'fast and easy' process.

This is a guide to taking data from a spreadsheet and easily moving that data into a MySQL database instance. The trick is the Import Wizard in MySQL Workbench that does a lot of the detail work for you. In a future post we will go into what you have to do when you are not …

Transportable tablespaces were introduced in MySQL 5.6. Using this feature, we can directly copy a tablespace to another server and populate the table with data. This is a very useful feature for large tables. The transportable tablespace mechanism is faster than any other method for exporting and importing tables because the files containing the data just need to be copied to the target location using traditional Linux commands (cp, scp, rsync). Our post MySQL 5.6 Transportable Tablespaces best practices covers the best practices about transportable tablespaces. The feature also supports encrypted tablespaces, and in this article, I am going to explain how to use this feature with them.

Requirements

Below I am sharing my current setup and the requirements.

• I have two servers – s1 and s2. …

The article covers the basic syntax of a MySQL SELECT statement and provides examples that show how to use a MySQL SELECT statement to retrieve data from tables. The primary task in database management is writing and executing queries – commands for retrieving and manipulating data in databases. Users describe the tasks via these queries, […]

The post MySQL SELECT Statement Basics appeared first on Devart Blog.

Where I work, we are using MySQL a lot. The databases are being organized in replication hierarchies, and each hierarchy is a tree topology with a single primary and a number of intermediate replicas.

Replication is a tree managed by Orchestrator

We are using MySQL orchestrator to manage the replication topology.

MySQL Orchestrator shows a typical replication hierarchy. Each color indicates a different data center/availability zone. Replication is a tree, from the primary to per-AZ intermediate replicas for fan-out to leaf replicas. Clients connect to the primary for writing, and to the leaf replicas for reading. Special instances exist as clone sources and backup instances.

The diagram above is the view presented by …