Date and time values are some of the most important datatypes in an RDBMS. From tracking order dates to payroll hours, DATE and DATETIME datatypes are used in all types of applications. At times as a Developer, you may need only certain portions of a DATE or DATETIME value. In MySQL, the EXTRACT() function can provide you with a specific component of a DATE or DATETIME value depending on which INTERVAL is given as a parameter. Continue reading to see example EXTRACT() queries for understanding…

Photo by Omar Al-Ghossen on Unsplash …

There is a new MySQL 8.0 release and it has some interesting replication features. The change log is available at the usual place, MySQL 8.0.21, but let me give you a brief summary.

• Binary Log Checksums Support for Group Replication (WL#9038).

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We are pleased to announce the release of MySQL Cluster 8.0.21, the latest GA, along with 7.6.15, 7.5.19, 7.4.29, and 7.3.30. MySQL Cluster is the distributed, shared-nothing variant of MySQL. This storage engine provides: In-Memory storage – Real-time performance (with optional checkpointing to disk) Transparent Auto-Sharding – Read & write scalability Active-Active/Multi-Master geographic replication 99.999% […]

Dear MySQL users,

MySQL Shell 8.0.21 is a maintenance release of MySQL Shell 8.0 Series (a
component of the MySQL Server). The MySQL Shell is provided under
Oracle’s dual-license.

MySQL Shell 8.0 is highly recommended for use with MySQL Server 8.0 and
5.7. Please upgrade to MySQL Shell 8.0.21.

MySQL Shell is an interactive JavaScript, Python and SQL console
interface, supporting development and administration for the MySQL
Server. It provides APIs implemented in JavaScript and Python that
enable you to work with MySQL InnoDB cluster and use MySQL as a document
store.

The AdminAPI enables you to work with MySQL InnoDB cluster and InnoDB
ReplicaSet, providing integrated solutions for high availability and scalability
using InnoDB based MySQL databases, without requiring advanced MySQL
expertise.  For more …

Dear MySQL users,

MySQL Shell 8.0.20 is a maintenance release of MySQL Shell 8.0 Series (a
component of the MySQL Server). The MySQL Shell is provided under
Oracle’s dual-license.

MySQL Shell 8.0 is highly recommended for use with MySQL Server 8.0 and
5.7. Please upgrade to MySQL Shell 8.0.20.

MySQL Shell is an interactive JavaScript, Python and SQL console
interface, supporting development and administration for the MySQL
Server. It provides APIs implemented in JavaScript and Python that
enable you to work with MySQL InnoDB cluster and use MySQL as a document
store.

The AdminAPI enables you to work with MySQL InnoDB cluster and InnoDB
ReplicaSet, providing integrated solutions for high availability and scalability
using InnoDB based MySQL databases, without requiring advanced MySQL
expertise.  For more …

In MySQL 8.0.21, we can see who and how mysqld was stopped and when the process ended.

Let’s have a look at different scenarios in this article.

SHUTDOWN SQL statement

The first test is to initiate the shutdown of MySQL from a SQL client:

mysql> shutdown;

In the error log (log_error_verbosity is set to 2, the default), we can see:

2020-07-14T07:17:28.865274Z 10 [System] [MY-013172] [Server] 
          Received SHUTDOWN from user root. Shutting down mysqld (Version: 8.0.21).
2020-07-14T07:17:31.258884Z 0 [System] [MY-010910] [Server] 
         /usr/sbin/mysqld: Shutdown complete (mysqld 8.0.21) MySQL Community Server - GPL.

We can easily identify when the server started the shutdown process and when it finished.

Stopping using systemd

MySQL 8.0.21 is out, and the WARP storage engine has been updated to support the changes made in the new version.

There are no significant functionality changes to the storage engine for MySQL 8.0.21, only the minor changes required to compile in the new version.  

I will be posting benchmarks of WARP vs InnoDB and Column Store using the Star Schema Benchmark, DBT3, and some other comparison tests.

I will also be releasing a Docker image to make testing WARP easy.  As always, binaries are available upon request.  Keep in mind that WARP is a pluggable storage engine, and you can request just the plugin, or the whole MySQL 8 release,  for version 8.0.19, 8.0.20, or 8.0.21.

MySQL 8.0.21 has been released today, wooohooo \o/

As usual, this release contains contributions and let me thanks all the contributors on behalf of the MySQL Team.

MySQL 8.0.21 includes contributions from Edgars Irmejs, Daniël van Eeden, Jeremy Cole, Wenfeng Shih, Billy O’Neal, Lou Shuai, Tsubasa Tanaka and Facebook.

Thank you all for your great contributions. MySQL is an Open Source project, GPL, and we accept contributions !

Here is the list of the contributions above:

• Filesort …

MySQL 8.0.21 was released today and one of the many new features is the JSON_VALUE() function. The main motivation is to ease index creation values from JSON data but there is more to it.

JSON_VALUE() finds a specified scalar JSON value in JSON data and returns it as a SQL value.

Examples
I will use the mysql_x example database data for examples.   So let us start with getting the life expectancy data.

SELECT JSON_EXTRACT(doc, "$.demographics.LifeExpectancy") AS raw 
FROM countryinfo 
LIMIT 4;
+--------------------+
| raw                |
+--------------------+
| 78.4000015258789   |
| 45.900001525878906 |
| 38.29999923706055  |
| 76.0999984741211   |
+--------------------+

That is great information …

     Recently the MySQL 8.0 Developer Certification became available joining the MySQL 8.0 Developer Certifications.  I have recently seen posts on various social media sites asking what is on the exam, is there an exam guide, and what do you 'really need to know' to pass the exam.

   Both tests are very tough.  Neither is going to be passed by rote memorization as many of the questions require analysis of system output before trying to adjust for the desired result.  There are no true or false questions and no essays.  What you will get is a series of questions written by subject matter experts that range from testing basic conceptual knowledge to very tough assessments of how to fix problems.  BTW the exam software lets you mark questions for later review and it does help to bypass the tougher questions for later review at the end of the test.

  Are the question …