$ brew info mariadb🆑
mariadb: stable 10.3.14
Drop-in replacement for MySQL
https://mariadb.org/
Conflicts with:
  mariadb-connector-c (because both install plugins)
  mysql (because mariadb, mysql, and percona install the same binaries.)
  mysql-cluster (because mariadb, mysql, and percona install the same binaries.)
  mysql-connector-c (because both install MySQL client libraries)
  mytop (because both install `mytop` binaries)
  percona-server (because mariadb, mysql, and percona install the same binaries.)
/usr/local/Cellar/mariadb/10.3.14 (653 files, 173.5MB) *🈁
  Built from source on 2019-04-10 at 21:58:51
From: https://github.com/Homebrew/homebrew-core/blob/master/Formula/mariadb.rb
==> Dependencies
Build: cmake ✔
Required: openssl ✔
==> Caveats
A "/etc/my.cnf"🈁 from another install may interfere with a Homebrew-built
server starting up correctly.

MySQL is configured to only allow connections from localhost by default

To connect:
    mysql -uroot

To have launchd start mariadb now and restart at login:
  brew services start mariadb🈁
Or, if you don't want/need a background service you can just run:
  mysql.server start
==> Analytics
install: 19,276 (30 days), 49,267 (90 days), 165,865 (365 days)
install_on_request: 18,357 (30 days), 47,053 (90 days), 155,100 (365 days)
build_error: 0 (30 days)
$

$ cat /etc/my.cnf🆑
cat: /etc/my.cnf: No such file or directory
$

$ mysql --help|grep cnf
/usr/local/etc/my.cnf ~/.my.cnf
                      order of preference, my.cnf, $MYSQL_TCP_PORT,

$ ls -la /usr/local/etc/my.cnf🆑
-rw-r--r-- 1 server admin 212  4 10 21:58 /usr/local/etc/my.cnf
$ ls -la ~/.my.cnf🆑
ls: cannot access '/Users/ujpadmin/.my.cnf': No such file or directory
$

$ cat  /usr/local/etc/my.cnf🆑
#
# This group is read both both by the client and the server
# use it for options that affect everything
#
[client-server]

#
# include all files from the config directory
#
!includedir /usr/local/etc/my.cnf.d

$

$ brew services start mariadb🆑
==> Tapping homebrew/services
Cloning into '/usr/local/Homebrew/Library/Taps/homebrew/homebrew-services'...
remote: Enumerating objects: 17, done.
remote: Counting objects: 100% (17/17), done.
remote: Compressing objects: 100% (14/14), done.
remote: Total 17 (delta 0), reused 12 (delta 0), pack-reused 0
Unpacking objects: 100% (17/17), done.
Tapped 1 command (50 files, 62.8KB).
==> Successfully started `mariadb` (label: homebrew.mxcl.mariadb)🈁
$

$ ps -ef|grep mariadb🆑
  501 16043     1   0 10:41PM ??         0:00.03 /bin/sh /usr/local/opt/mariadb/bin/mysqld_safe
 --datadir=/usr/local/var/mysql
  501 16140 16043   0 10:41PM ??         0:00.31 /usr/local/opt/mariadb/bin/mysqld
 --basedir=/usr/local/opt/mariadb
 --datadir=/usr/local/var/mysql🈁
 --plugin-dir=/usr/local/opt/mariadb/lib/plugin
 --log-error=/usr/local/var/mysql/plute.local.err🈁
 --pid-file=plute.local.pid
$

$ ls -la /usr/local/var/mysql🆑
total 122936
drwxr-xr-x 16 server admin      544  4 11 22:41 .
drwxrwxr-x  8 server admin      272  4 10 23:36 ..
-rw-rw----  1 server admin    16384  4 10 21:59 aria_log.00000001
-rw-rw----  1 server admin       52  4 10 21:59 aria_log_control
-rw-r-----  1 server admin      972  4 10 21:59 ib_buffer_pool
-rw-rw----  1 server admin 50331648  4 11 22:41 ib_logfile0
-rw-rw----  1 server admin 50331648  4 10 21:59 ib_logfile1
-rw-rw----  1 server admin 12582912  4 10 21:59 ibdata1
-rw-rw----  1 server admin 12582912  4 11 22:41 ibtmp1
-rw-rw----  1 server admin        0  4 11 22:41 multi-master.info
drwx------ 91 server admin     3094  4 10 21:59 mysql
drwx------  3 server admin      102  4 10 21:59 performance_schema
-rw-rw----  1 server admin     1607  4 11 22:41 plute.local.err
-rw-rw----  1 server admin        6  4 11 22:41 plute.local.pid
-rw-rw----  1 server admin    24576  4 11 22:41 tc.log
drwx------  3 server admin      102  4 10 21:59 test
$

$ cat /usr/local/var/mysql/plute.local.err🆑
2019-04-11 22:41:41 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2019-04-11 22:41:41 0 [Note] InnoDB: Uses event mutexes
2019-04-11 22:41:41 0 [Note] InnoDB: Compressed tables use zlib 1.2.5
2019-04-11 22:41:41 0 [Note] InnoDB: Number of pools: 1
2019-04-11 22:41:41 0 [Note] InnoDB: Using generic crc32 instructions
2019-04-11 22:41:41 0 [Note] InnoDB: Initializing buffer pool, total size = 128M, instances
 = 1, chunk size = 128M
2019-04-11 22:41:41 0 [Note] InnoDB: Completed initialization of buffer pool
2019-04-11 22:41:41 0 [Note] InnoDB: 128 out of 128 rollback segments are active.
2019-04-11 22:41:41 0 [Note] InnoDB: Creating shared tablespace for temporary tables
2019-04-11 22:41:41 0 [Note] InnoDB: Setting file './ibtmp1' size to 12 MB. Physically
 writing the file full; Please wait ...
2019-04-11 22:41:42 0 [Note] InnoDB: File './ibtmp1' size is now 12 MB.
2019-04-11 22:41:42 0 [Note] InnoDB: 10.3.14 started; log sequence number 1630815;
 transaction id 21
2019-04-11 22:41:42 0 [Note] InnoDB: Loading buffer pool(s) from
 /usr/local/var/mysql/ib_buffer_pool
2019-04-11 22:41:42 0 [Note] Plugin 'FEEDBACK' is disabled.
2019-04-11 22:41:42 0 [Note] InnoDB: Buffer pool(s) load completed at 190411 22:41:42
2019-04-11 22:41:42 0 [Note] Server socket created on IP: '::'.
2019-04-11 22:41:42 0 [Note] Reading of all Master_info entries succeded
2019-04-11 22:41:42 0 [Note] Added new Master_info '' to hash table
2019-04-11 22:41:42 0 [Note] /usr/local/opt/mariadb/bin/mysqld: ready for connections.🈁
Version: '10.3.14-MariaDB'  socket: '/tmp/mysql.sock'  port: 3306  Homebrew
$