1. mariadb-server – The MariaDB server.
2. mariadb-client – The client side of MariaDB server including mysqlclient library and headers for the MariaDB client API.

How to search for MariaDB packages

Run the following pkg_info command along with grep command:
pkg_info -Q mariadb
Search for PHP client that can access mariadb server:
pkg_info -Q mariadb | grep php

OpenBSD install MariaDB database server using pkg_add

Type the following pkg_add command to install MariaDB on OpenBSD 6.4:
# pkg_add -v mariadb-server
OR
$ doas pkg_add -v mariadb-server

How to install MariaDB client on OpenBSD

Simply run:
# pkg_add -v mariadb-client
OR
$ doas pkg_add -v mariadb-client

How to enable and start MariaDB server at boot time on OpenBSD

To configure and control daemons and services on OpenBSD use rcctl command

Enable MariaDB

# rcctl enable mysqld
OR
$ doas rcctl enable mysqld

Initialize MariaDB data directory

You need to run mysql_install_db command. It initializes the MariaDB data directory and creates the system tables:
# mysql_install_db

Start MariaDB service on OpenBSD

# rcctl start mysqld

Stop MariaDB service on OpenBSD

# rcctl stop mysqld

Restart MariaDB service on OpenBSD

# rcctl restart mysqld

Check MariaDB service status on OpenBSD

# rcctl check mysqld

Verify that MariDB service running and port is open

Run pgrep command to searche the process named mysqld:
# pgrep mysqld
Another option is to run ps command:
# ps aux | grep mysqld
Verify that TCP port 3306 is open using netstat command:
# netstat -f inet -na
# netstat -f inet -na | grep 3306

How to secure MariaDB installation

Run the following script:
# mysql_secure_installation

How to test MariaDB installation

Run the following mysql command:
mysql -u root -p

How to configure MariaDB on OpenBSD 6.4

Edit /etc/my.cnf file:
# vi /etc/my.cnf
For example, change IP address binding from localhost:
bind-address = 127.0.0.1
To LAN IP address 192.168.2.200:
bind-address = 192.168.2.200
Save and close the file. Restart mysqld service on OpenBSD:
# rcctl restart mysqld

How to open MariaDB port using PF firewall on OpenBSD

Simply add the following rule to /etc/pf.conf

pass in proto tcp from 192.168.2.0/24 to any port 3306 keep state

Test it and reload the rules:
# pfctl -v -nf /etc/pf.conf
# pfctl -v -f /etc/pf.conf

Conclusion

You learned how to set up and install MariaDB on OpenBSD. For more information see the official MariaDB site here and pkg_add page here and recommended MariaDB books here.