This commit introduces a MySQL container and an Adminer container to the docker-compose.yml file. The dependencies list was also updated, swapping the 'app' and 'db' listings to ensure the correct start-up order. An additional MySQL configuration file was added to mitigate heavy CPU usage. A new .gitignore file is also introduced to avoid unintended inclusion of database files in version control.

docker/dev/.gitignore

@@ -0,0 +1,2 @@
+db/*
+!db/.gitignore

docker/dev/my.cnf

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+[mysqld]
+innodb_lru_scan_depth=100  # from 1024 to conserve 90% CPU cycles used for function
+innodb_io_capacity=1900  # from 200 to allow more IOPSecond to your storage device
+innodb_flush_neighbors=2  # from 0 to expedite writing to current extent
+innodb_max_dirty_pages_pct_lwm=1  # from 10 percent to expedite writes
+innodb_max_dirty_pages_pct=1  # from 90 percent to reduce innodb_buffer_pool_pages_dirty count
+innodb_change_buffer_max_size=50  # from 25 percent to expedite your high volume activity
+innodb_flush_log_at_trx_commit=0
+skip_log_bin=1