UNION and UNION ALL set operators return the combined rows from 1 or more SELECT queries. CodeIgniter 4 Query Builder now supports UNION and UNION ALL queries with the $builder->union() and $builder->unionAll() methods respectively. Learn how to create these types of queries in this article.

This article and many to follow, are part of a series of articles I am writing and sharing as I learn new concepts when I learn them. I think of it as a duty in sharing the things I learn as a self-taught developer. We all need to support one another as we continue to learn and grow. #buildinpublic #learninpublic #indiehackers #developer

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Percona Server for MySQL 8.0.30-22 introduces several improvements for the LDAP plugin: SASL support, support for fallback servers, and support for LDAP-based authorization. All improvements are in technical preview.

A description of the existing plugin features and usage instructions are available in the earlier blog post introducing the LDAP simple plugin, and in the Percona Server for MySQL documentation.

SASL connections

We introduced a new plugin similar to the MySQL …

What is a Delay Replica and how does it help?

MySQL Replication is useful, easy to set up, and used for very different purposes. For example:

• split reads and writes
• run data mining or reporting processes on them
• disaster recovery

To learn more, check out How Does MySQL Replication Work?

It’s important to mention that a replication server is not a backup by itself. A mistake on the source, for example, a DROP DATABASE or an UPDATE without a WHERE clause will be replicated nearly instantly to all replica servers. Simply having a replica is not going to be helpful here. How can we avoid that kind of mistake? By having a replica server that intentionally lags behind.

We can never avoid human error in database infrastructure operations. But …

Let’s continue our journey of deploying the MySQL Database System on OCI with Terraform. This time we will see how we can use a backup (see [1] and [2]) as a source (initial data) for a new instance. Within the oci_mysql_mysql_db_system it’s possible to define a source detailing how to provision the initial data of […]

Background In databases, rows are persisted on disk and for every row, columns’ value are stored on disk. Now, if a new column is to be added or an old column is to be dropped from a table, the contents of existing rows should be changed to reflect the correct values of columns present in […]

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