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Displaying posts with tag: MySQL (reset)
Secured MySQL InnoDB Cluster with Certificate creation using OpenSSL

This is a demo tutorial to show how we can create InnoDB Cluster with newly installed Certificate and having X509 certificate verification via MySQL Router connection.   

Recorded Video

The full process is recorded on Youtube - showing creating InnoDB Cluster with newly installed CA, Server Certificates.  The Router creation is configured with SSL Server certificate from the same CA certificate across Server nodes.   The creation of User (create user my509user identified by '....' require X509) using X509 certificate PASSTHROUGH verification via Router connection.


The following environment was tested 

Oracle Linux Server release 8.6

MySQL Server 8.0.31

MySQL Shell 8.0.31 …

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Bad Optimizer Plan on Queries Combining WHERE, ORDER BY and LIMIT

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 is an improved

10 Useful mysqladmin Commands for Database Administration

In this blog post, we will show you ten useful mysqladmin commands for database administration. Mysqladmin is a client for ...

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The post 10 Useful mysqladmin Commands for Database Administration appeared first on RoseHosting.

Enable innodb_print_all_deadlocks Parameter To Get All Deadlock Information in mysqld Error Log

At Percona Managed Services, sometimes clients’ applications face deadlock situations and need all historic deadlock information for application tuning.


RECORD LOCKS space id 163 page no 3 n bits 72 index GEN_CLUST_INDEX of table `deadlock_test`.`t` trx id 78507 lock_mode X waiting
TRANSACTION 78508, ACTIVE 155 sec starting index read
mysql tables in use 1, locked 1

But how could we view all past deadlock information?

We could enable innodb_print_all_deadlocks,  and all deadlocks in InnoDB user transactions will be recorded in the MySQL error log.

Let‘s start the test.

Create the test …

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OpenLampTech issue #52 – Substack Repost

Unbelievably, the OpenLampTech developer newsletter is one year old. Thank you so much for reading and making it possible! I appreciate each and every one of you.

The Newsletter for PHP and MySQL Developers

Receive a copy of my ebook, “10 MySQL Tips For Everyone”, absolutely free when you subscribe to the OpenLampTech newsletter.

In this week’s OpenLampTech issue #52, we have articles covering:

  • MySQL ordering with NULL
  • 7 WordPress tips for professionals
  • MySQL GUI clients for Linux
  • Working with WordPress custom tables
  • And much much more

Want to support the OpenLampTech

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pre-FOSDEM MySQL Days 2023

Hello dear MySQL Community !

As you may already know FOSDEM 2023 is again going to be held in-person. FOSDEM will take place February 4th and 5th 2023.

We have also decided to put our pre-FOSDEM MySQL Day on track for a fifth edition.

As for the last edition, the event will be spread over 2 days.

These 2 extra days related to the world’s most popular open source database will take place just before FOSDEM, the 2nd and 3rd February at the usual location in Brussels.

Please don’t forget to register as soon as possible as you may already know, the seats are limited !

Register on eventbrite:

And, please don’t forget, that if you have register for the event and you cannot make it, please free back your ticket …

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ProxySQL Support for MySQL caching_sha2_password

Every day we use dozens if not hundreds of applications connecting to some kind of data repository. This simple step is normally executed over the network and, given so, it is subject to possible sniffing with all the possible related consequences.

Given that, it is normally better to protect your connection using data encryption like SSL, or at the minimum, make the information you pass to connect less easy to be intercepted.

At the same time, it is a best practice to not store connection credentials in clear text, not even inside a table in your database. Doing that is the equivalent of writing your password on a sticky note on your desk. Not a good idea.

Instead, the main options are either transforming the passwords to be less identifiable via hashing or storing the information in an external centralized vault.

In MySQL, the passwords are transformed to not be clear text, and several different plugins …

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Journée MySQL Innovation et Cloud

Next week, November 16th, I will participate to the MySQL Innovation and Cloud Virtual Day in French.

My colleagues will present what’s new in MySQL 8.0.31 and also summarize all the big news that was announced at Oracle Cloud World in Las Vegas.

Attendees will learn about the MySQL HeatWave offering in OCI.

I will be presenting something that is only available in MySQL on-prem and in OCI as a managed service: MySQL Document Store.

The event is in French and attendees will have the opportunity to discuss and chat with MySQL experts (included Olivier!!) during the event.

Registration is required to attend this free event: Register Here.

On se voit la semaine prochaine !


MySQL 8.0.31 added INTERSECT and EXCEPT to augment the long-lived UNION operator. That is the good news. The bad news is that you have to be careful using the EXCEPT operator as there is a trick.

Let’s start with some simple tables and load some simple data.

SQL > create table a (id int, nbr int);
Query OK, 0 rows affected (0.0180 sec)
SQL > create table b (id int, nbr int);
Query OK, 0 rows affected (0.0199 sec)
SQL > insert into a (id,nbr) values (1,10),(3,30),(5,50),(7,70);
Query OK, 4 rows affected (0.0076 sec)

Records: 4  Duplicates: 0  Warnings: 0
SQL > insert into b (id,nbr) values (1,10),(2,20),(3,30),(4,40);
Query OK, 4 rows affected (0.0159 sec)

Records: 4  Duplicates: 0  Warnings: 0

So each table has four rows of data with two rows – (1,10) and (3,30) – appearing in both.

SQL > select id,nbr from a;
| id | nbr |
|  1 |  10 |
|  3 |  30 |
|  5 |  50 |
|  7 |  70 | …
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ODA : Do You Know The MOVE Table In MySQL DB Repository

During a consulting on a customer, we faced the following issue when trying to delete a dbhome

Message:  DCS-10001:Internal error encountered: PRGO-2470 : Working copy “OraDB19000_home1” is involved in an incomplete move or upgrade operation

The result of the job is shown below

[2022-11-08 10:53:35 root@odaserverb]# odacli describe-job -i 671b5899-02ac-45ff-b5af-ee254ef0bc72

Job details
                     ID:  671b5899-02ac-45ff-b5af-ee254ef0bc72
            Description:  Database Home OraDB19000_home1 Deletion with id a1bfe23e-2569-407b-8b87-7af9f9f586bf
                 Status:  Failure
                Created:  October 26, 2022 6:45:49 AM CEST
                Message:  DCS-10001:Internal error encountered: PRGO-2470 : Working copy "OraDB19000_home1" is involved in an incomplete move or upgrade operation..

Task Name …
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