ProxySQL is a very useful tool for gaining high availability, load balancing, query routing, query caching, query rewriting, multiplexing, and data masking. It is a proven tool and is used largely in production. There can be an instance of ProxySQL using a lot of memory on the server. This post is related to one of the causes that can use memory on the ProxySQL server and how we handle it.

Explanation

How do we know where the memory is getting used?

Proxysql has a stats database which we can see with an admin login. This database contains metrics gathered by ProxySQL concerning its internal functioning.

This post mostly talks about stats in MySQL query digest in ProxySQL.

Memory used by query digest can grow unlimited, and you can query the memory usage with the below query with an admin login. The memory usage is shown in bytes. 

MySQL [(none)]> select * from …

The need to audit who is using a database and their activities is crucial in many environments. This functionality is available in the free, open source Audit Plugin that is included in Percona Server for MySQL.

The prerequisite for installing Percona’s Audit Log Plugin is to first install Percona Server for MySQL. Percona Server for MySQL is a drop-in replacement for MySQL.

The Audit Log Plugin itself is easy to install requiring only a shared object library to be loaded from a MySQL client program with INSTALL PLUGIN audit_log SONAME ‘audit_log.so’;.

stoker@testbox:~/Downloads$ mysql -u root -p mysql
Enter password:
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Welcome to the MySQL monitor. Commands end with ; or g.
Your MySQL …

Recently, for the 3rd day of the MySQL Community Advent Calendar 2022,  I wrote an article on how to define a backup policy for MySQL Database Service in OCI using Terraform. We saw that it was possible to define tags (defined_tags and freeform_tags) in the backup_policy section of a oci_mysql_mysql_db_system resource. However, it seems that […]

For this new MySQL Advent Calendar 2022, today’s post is related on how to define a Backup Policy and a Maintenance Window when deploying a MySQL Database Service instance in OCI using Terraform. Backup Policy In the oci_mysql_mysql_db_system resource, we will add a new section called backup_policy like this: backup_policy { is_enabled = "true" retention_in_days […]

If, in Percona Server, you are observing tail latencies on queries that should be fast, this might be a side effect of Percona's improved InnoDB Empty Free List Algorithm.  When using this algorithm (the default in 5.6 and 5.7 and optional configuration in 8.0), a query needing a free page while none are available waits until the LRU Manager Thread refills the free list.  Because this

If you are using MyDumper as your Logical Backup solution and you store your backups on S3, you need to take a local backup and then upload it to S3. But what if there is not enough space to hold the backup on the server where we are taking the backup? Even if we have enough disk space, we will need to wait until the end to start to upload the files, making the whole process longer.

MyDumper implemented stream backup in v0.11.3 and we have been polishing the code since then. We also implemented two ways of executing external commands:

−−exec-per-thread: The worker that is getting the data from the database will write and redirect to the STDIN of the external command. It will be similar to execute cat FILE | command per every written and closed file.

−−exec: In this case, the worker writes in the local storage and when the file is closed, the filename is enqueued. The exec …

While the LAMP stack – Linux/Apache/MySQL/PHP – is not the dominant platform it was a decade ago, there are still many websites that depend on it. One of the pillars of this quartet had a milestone last week when PHP 8.0 passed into End Of Life status. While it will still have limited security issue support for another year, 8.0 should be phased out of your environments.

By the way, 8.1 has another year until it reaches End of Life status.

So please update your PHP 8.0 as soon as you can, double check the connector you are using to access your database is updated too, and make sure you are ready for 8.1’s future.

And make sure that if you are currently running MySQL 5.7 that you upgrade by October 2023 when it too reaches End of Life.

In my honest opinion, MS Access is one garbage of a database. More likely, database is too strong of a word. While I won’t be using Access in this article, there is a story there (but I’m not here to have an Access bash party). Continue reading for an example of how you may use a correlated subquery and simulate the LEAD() Window Function.

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The Primary key is like the hero of a row, which has more beneficial features in the table while performing any task on the table.

The DBA knows the importance of the primary key in the table and how to handle it.

1. Notable features of having a primary key:
2. Requirements:
3. Enabling GIPK:
4. Handling GIPK:
…

We all know that data is important, and some businesses need historical data to be available all the time. The problem is that queries on large tables perform poorly if they are not properly optimized. We get many customer requests in Managed Services to purge/archive large tables, and to achieve it, we use pt-archiver.

Recently, we received a request to archive a large table, and the customer was worried about the downtime and performance issues during the archival.

We proposed a solution to the customer to archive the table using pt-archive. The idea is to archive old data to other tables and keep the latest data on the current table with minimal performance issues. All of the data will remain available and can be queried anytime.

In the blog, I will …