A partitioned table in MySQL has its data separated into different tablespaces while still being viewed as a single table. Partitioning can be a useful approach in some cases when handling huge sets of data. Deleting huge data sets could be quickened up in a partitioned table, but if not handled properly, it can misplace your data in the table. In this blog, I will share how to check and fix the data in such a table with minimal disruption to the table.

In this example, we use a table partitioned based on a date range.

mysql> show create table salariesG
*************************** 1. row ***************************
       Table: salaries
Create Table: CREATE TABLE `salaries` (
  `emp_no` int(11) NOT NULL,
  `salary` int(11) NOT NULL,
  `from_date` date NOT NULL,
  `to_date` date NOT NULL,
  PRIMARY KEY (`emp_no`,`from_date`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1
/*!50500 PARTITION BY RANGE  COLUMNS(from_date)
(PARTITION p01 VALUES LESS …

As a MySQL DBA, you like to know who is connected on the system you manage. You also like to know who is trying to connect.

In this article, we will discover how we can retrieve the information and control who is using the MySQL DB instance we launched in OCI.

Secure Connections

The first thing we can check is that all our clients encrypt their connection to the MySQL server.

We use again Performance_Schema to retrieve the relevant information:

select connection_type, substring_index(substring_index(name,"/",2),"/",-1) name,
       sbt.variable_value AS tls_version, t2.variable_value AS cipher,
       processlist_user AS user, processlist_host AS host
from performance_schema.status_by_thread AS sbt
join performance_schema.threads AS t 
  on t.thread_id = sbt.thread_id
join performance_schema.status_by_thread AS t2 
  on t2.thread_id = t.thread_id
where sbt.variable_name = 'Ssl_version' and …

The End-of-Life (EOL) date for MySQL 5.7 is scheduled for October 2023, which means that after that date, MySQL 5.7 will no longer receive updates, bug fixes, or security patches. This does not mean that MySQL 5.7 will stop working after the EOL date, but it does mean that any issues or vulnerabilities discovered after that date will not be addressed, This can leave your database at risk of security breaches or performance issues. AWS RDS support for MySQL will also hold good only till October 2023.

To avoid these potential issues, it is recommended to upgrade to a newer version of MySQL before the EOL date for MySQL 5.7. Upgrading to a newer version such as MySQL 8 …

Blip is a new MySQL monitor that collects and reports server metrics. But wasn’t this problem solved long ago? Not really…

Blip is a new MySQL monitor that collects and reports server metrics. But wasn’t this problem solved long ago? Not really…

Blip is a new MySQL monitor that collects and reports server metrics. But wasn’t this problem solved long ago? Not really…

As a MySQL DBA, you like to know who is connected on the system you manage. You also like to know who is trying to connect. In this article, we will discover how we can retrieve the information and control who is using the MySQL DB instance we launched in OCI. Secure Connections The first […]

For this third article of the series dedicated on how a DBA can find the info he needs with MySQL Database Service in Oracle Cloud Infrastructure, we will see how we can find the error log.

When using MySQL DBAAS, the DBA doesn’t have direct access to the files on the filesystem. Hopefully, with MySQL 8.0, the error log is also available in Performance_Schema.

This is exactly where you will find the information present also in the error log file when using MDS in OCI:

select * from (select * from performance_schema.error_log order by logged desc limit 10) a order by logged\G
*************************** 1. row ***************************
    LOGGED: 2023-03-19 08:41:09.950266
 THREAD_ID: 0
      PRIO: System
ERROR_CODE: MY-011323
 SUBSYSTEM: Server
      DATA: X Plugin ready for connections. Bind-address: '10.0.1.33' port: 33060, socket: /var/run/mysqld/mysqlx.sock
*************************** 2. row …

On MySQL and Percona Server for MySQL, there is a schema called information_schema (I_S) which provides information about database tables, views, indexes, and more.

A lot of useful information can be retrieved from this schema, for example, table metadata and foreign key relations, but trying to query I_S can induce performance degradation if your server is under heavy load, as shown in the following example test.

Disclaimer: This blog post is meant to show a less-known problem but is not meant to be a serious benchmark. The percentage in degradation will vary depending on many factors {hardware, workload, number of tables, configuration, etc.}.

Test

The test compares a baseline of how the server behaves while “under heavy load but no queries against I_S” vs. ” under heavy load + I_S queries” to …

I changed the format a little bit for this week’s OpenLampTech newsletter. Still sharing the same great content, but, with less rambling on my part. Let me know what you think and thank you for reading.

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 OpenLampTech issue #71, I’m sharing great content on:

• Finding duplicate rows with SQL
• User input in Laravel securely
• WordPress Loop and Query Loop compared
• Get the current date in PHP
• And a whole lot more.

I appreciate you reading …