diff --git a/.examples/docker-compose/insecure/mariadb-cron-redis/apache/db/Dockerfile b/.examples/docker-compose/insecure/mariadb-cron-redis/apache/db/Dockerfile
new file mode 100644
index 00000000..d9a5cfb4
--- /dev/null
+++ b/.examples/docker-compose/insecure/mariadb-cron-redis/apache/db/Dockerfile
@@ -0,0 +1,4 @@
+FROM mariadb
+#FROM mysql
+
+COPY transaction-isolation.conf /etc/mysql/conf.d/transaction-isolation.conf
diff --git a/.examples/docker-compose/insecure/mariadb-cron-redis/apache/db/transaction-isolation.conf b/.examples/docker-compose/insecure/mariadb-cron-redis/apache/db/transaction-isolation.conf
new file mode 100644
index 00000000..527a3f0e
--- /dev/null
+++ b/.examples/docker-compose/insecure/mariadb-cron-redis/apache/db/transaction-isolation.conf
@@ -0,0 +1,5 @@
+[mysqld]
+# Set Transaction isolation Level to READ-COMMITED (Required by nextcloud)
+# ================================================
+#   https://docs.nextcloud.com/server/13/admin_manual/configuration_database/linux_database_configuration.html#database-read-commited-transaction-isolation-level
+transaction-isolation = READ-COMMITTED
diff --git a/.examples/docker-compose/insecure/mariadb-cron-redis/apache/docker-compose.yml b/.examples/docker-compose/insecure/mariadb-cron-redis/apache/docker-compose.yml
index ab307200..a08fc9fb 100644
--- a/.examples/docker-compose/insecure/mariadb-cron-redis/apache/docker-compose.yml
+++ b/.examples/docker-compose/insecure/mariadb-cron-redis/apache/docker-compose.yml
@@ -2,8 +2,7 @@ version: '3'
 
 services:
   db:
-    image: mariadb
-    # image: mysql
+    build: ./db
     restart: always
     volumes:
       - db:/var/lib/mysql
diff --git a/.examples/docker-compose/insecure/mariadb-cron-redis/fpm/db/Dockerfile b/.examples/docker-compose/insecure/mariadb-cron-redis/fpm/db/Dockerfile
new file mode 100644
index 00000000..d9a5cfb4
--- /dev/null
+++ b/.examples/docker-compose/insecure/mariadb-cron-redis/fpm/db/Dockerfile
@@ -0,0 +1,4 @@
+FROM mariadb
+#FROM mysql
+
+COPY transaction-isolation.conf /etc/mysql/conf.d/transaction-isolation.conf
diff --git a/.examples/docker-compose/insecure/mariadb-cron-redis/fpm/db/transaction-isolation.conf b/.examples/docker-compose/insecure/mariadb-cron-redis/fpm/db/transaction-isolation.conf
new file mode 100644
index 00000000..527a3f0e
--- /dev/null
+++ b/.examples/docker-compose/insecure/mariadb-cron-redis/fpm/db/transaction-isolation.conf
@@ -0,0 +1,5 @@
+[mysqld]
+# Set Transaction isolation Level to READ-COMMITED (Required by nextcloud)
+# ================================================
+#   https://docs.nextcloud.com/server/13/admin_manual/configuration_database/linux_database_configuration.html#database-read-commited-transaction-isolation-level
+transaction-isolation = READ-COMMITTED
diff --git a/.examples/docker-compose/insecure/mariadb-cron-redis/fpm/docker-compose.yml b/.examples/docker-compose/insecure/mariadb-cron-redis/fpm/docker-compose.yml
index 92fe787d..76f7863a 100644
--- a/.examples/docker-compose/insecure/mariadb-cron-redis/fpm/docker-compose.yml
+++ b/.examples/docker-compose/insecure/mariadb-cron-redis/fpm/docker-compose.yml
@@ -2,8 +2,7 @@ version: '3'
 
 services:
   db:
-    image: mariadb
-    # image: mysql
+    build: ./db
     restart: always
     volumes:
       - db:/var/lib/mysql
diff --git a/.examples/docker-compose/insecure/mariadb/apache/db/Dockerfile b/.examples/docker-compose/insecure/mariadb/apache/db/Dockerfile
new file mode 100644
index 00000000..d9a5cfb4
--- /dev/null
+++ b/.examples/docker-compose/insecure/mariadb/apache/db/Dockerfile
@@ -0,0 +1,4 @@
+FROM mariadb
+#FROM mysql
+
+COPY transaction-isolation.conf /etc/mysql/conf.d/transaction-isolation.conf
diff --git a/.examples/docker-compose/insecure/mariadb/apache/db/transaction-isolation.conf b/.examples/docker-compose/insecure/mariadb/apache/db/transaction-isolation.conf
new file mode 100644
index 00000000..527a3f0e
--- /dev/null
+++ b/.examples/docker-compose/insecure/mariadb/apache/db/transaction-isolation.conf
@@ -0,0 +1,5 @@
+[mysqld]
+# Set Transaction isolation Level to READ-COMMITED (Required by nextcloud)
+# ================================================
+#   https://docs.nextcloud.com/server/13/admin_manual/configuration_database/linux_database_configuration.html#database-read-commited-transaction-isolation-level
+transaction-isolation = READ-COMMITTED
diff --git a/.examples/docker-compose/insecure/mariadb/apache/docker-compose.yml b/.examples/docker-compose/insecure/mariadb/apache/docker-compose.yml
index 4ea67755..d5612444 100644
--- a/.examples/docker-compose/insecure/mariadb/apache/docker-compose.yml
+++ b/.examples/docker-compose/insecure/mariadb/apache/docker-compose.yml
@@ -2,8 +2,7 @@ version: '3'
 
 services:
   db:
-    image: mariadb
-    # image: mysql
+    build: ./db
     restart: always
     volumes:
       - db:/var/lib/mysql
diff --git a/.examples/docker-compose/insecure/mariadb/fpm/db/Dockerfile b/.examples/docker-compose/insecure/mariadb/fpm/db/Dockerfile
new file mode 100644
index 00000000..d9a5cfb4
--- /dev/null
+++ b/.examples/docker-compose/insecure/mariadb/fpm/db/Dockerfile
@@ -0,0 +1,4 @@
+FROM mariadb
+#FROM mysql
+
+COPY transaction-isolation.conf /etc/mysql/conf.d/transaction-isolation.conf
diff --git a/.examples/docker-compose/insecure/mariadb/fpm/db/transaction-isolation.conf b/.examples/docker-compose/insecure/mariadb/fpm/db/transaction-isolation.conf
new file mode 100644
index 00000000..527a3f0e
--- /dev/null
+++ b/.examples/docker-compose/insecure/mariadb/fpm/db/transaction-isolation.conf
@@ -0,0 +1,5 @@
+[mysqld]
+# Set Transaction isolation Level to READ-COMMITED (Required by nextcloud)
+# ================================================
+#   https://docs.nextcloud.com/server/13/admin_manual/configuration_database/linux_database_configuration.html#database-read-commited-transaction-isolation-level
+transaction-isolation = READ-COMMITTED
diff --git a/.examples/docker-compose/insecure/mariadb/fpm/docker-compose.yml b/.examples/docker-compose/insecure/mariadb/fpm/docker-compose.yml
index dc3a8aaf..7b9cd4b6 100644
--- a/.examples/docker-compose/insecure/mariadb/fpm/docker-compose.yml
+++ b/.examples/docker-compose/insecure/mariadb/fpm/docker-compose.yml
@@ -2,8 +2,7 @@ version: '3'
 
 services:
   db:
-    image: mariadb
-    # image: mysql
+    build: ./db
     restart: always
     volumes:
       - db:/var/lib/mysql
diff --git a/.examples/docker-compose/with-nginx-proxy/mariadb-cron-redis/apache/db/Dockerfile b/.examples/docker-compose/with-nginx-proxy/mariadb-cron-redis/apache/db/Dockerfile
new file mode 100644
index 00000000..d9a5cfb4
--- /dev/null
+++ b/.examples/docker-compose/with-nginx-proxy/mariadb-cron-redis/apache/db/Dockerfile
@@ -0,0 +1,4 @@
+FROM mariadb
+#FROM mysql
+
+COPY transaction-isolation.conf /etc/mysql/conf.d/transaction-isolation.conf
diff --git a/.examples/docker-compose/with-nginx-proxy/mariadb-cron-redis/apache/db/transaction-isolation.conf b/.examples/docker-compose/with-nginx-proxy/mariadb-cron-redis/apache/db/transaction-isolation.conf
new file mode 100644
index 00000000..527a3f0e
--- /dev/null
+++ b/.examples/docker-compose/with-nginx-proxy/mariadb-cron-redis/apache/db/transaction-isolation.conf
@@ -0,0 +1,5 @@
+[mysqld]
+# Set Transaction isolation Level to READ-COMMITED (Required by nextcloud)
+# ================================================
+#   https://docs.nextcloud.com/server/13/admin_manual/configuration_database/linux_database_configuration.html#database-read-commited-transaction-isolation-level
+transaction-isolation = READ-COMMITTED
diff --git a/.examples/docker-compose/with-nginx-proxy/mariadb-cron-redis/apache/docker-compose.yml b/.examples/docker-compose/with-nginx-proxy/mariadb-cron-redis/apache/docker-compose.yml
index b4ff47ad..65561cbe 100644
--- a/.examples/docker-compose/with-nginx-proxy/mariadb-cron-redis/apache/docker-compose.yml
+++ b/.examples/docker-compose/with-nginx-proxy/mariadb-cron-redis/apache/docker-compose.yml
@@ -2,8 +2,7 @@ version: '3'
 
 services:
   db:
-    image: mariadb
-    # image: mysql
+    build: ./db
     restart: always
     volumes:
       - db:/var/lib/mysql
diff --git a/.examples/docker-compose/with-nginx-proxy/mariadb-cron-redis/fpm/db/Dockerfile b/.examples/docker-compose/with-nginx-proxy/mariadb-cron-redis/fpm/db/Dockerfile
new file mode 100644
index 00000000..d9a5cfb4
--- /dev/null
+++ b/.examples/docker-compose/with-nginx-proxy/mariadb-cron-redis/fpm/db/Dockerfile
@@ -0,0 +1,4 @@
+FROM mariadb
+#FROM mysql
+
+COPY transaction-isolation.conf /etc/mysql/conf.d/transaction-isolation.conf
diff --git a/.examples/docker-compose/with-nginx-proxy/mariadb-cron-redis/fpm/db/transaction-isolation.conf b/.examples/docker-compose/with-nginx-proxy/mariadb-cron-redis/fpm/db/transaction-isolation.conf
new file mode 100644
index 00000000..527a3f0e
--- /dev/null
+++ b/.examples/docker-compose/with-nginx-proxy/mariadb-cron-redis/fpm/db/transaction-isolation.conf
@@ -0,0 +1,5 @@
+[mysqld]
+# Set Transaction isolation Level to READ-COMMITED (Required by nextcloud)
+# ================================================
+#   https://docs.nextcloud.com/server/13/admin_manual/configuration_database/linux_database_configuration.html#database-read-commited-transaction-isolation-level
+transaction-isolation = READ-COMMITTED
diff --git a/.examples/docker-compose/with-nginx-proxy/mariadb-cron-redis/fpm/docker-compose.yml b/.examples/docker-compose/with-nginx-proxy/mariadb-cron-redis/fpm/docker-compose.yml
index cfbfa91e..cb03fe93 100644
--- a/.examples/docker-compose/with-nginx-proxy/mariadb-cron-redis/fpm/docker-compose.yml
+++ b/.examples/docker-compose/with-nginx-proxy/mariadb-cron-redis/fpm/docker-compose.yml
@@ -2,8 +2,7 @@ version: '3'
 
 services:
   db:
-    image: mariadb
-    # image: mysql
+    build: ./db
     restart: always
     volumes:
       - db:/var/lib/mysql
diff --git a/.examples/docker-compose/with-nginx-proxy/mariadb/apache/db/Dockerfile b/.examples/docker-compose/with-nginx-proxy/mariadb/apache/db/Dockerfile
new file mode 100644
index 00000000..d9a5cfb4
--- /dev/null
+++ b/.examples/docker-compose/with-nginx-proxy/mariadb/apache/db/Dockerfile
@@ -0,0 +1,4 @@
+FROM mariadb
+#FROM mysql
+
+COPY transaction-isolation.conf /etc/mysql/conf.d/transaction-isolation.conf
diff --git a/.examples/docker-compose/with-nginx-proxy/mariadb/apache/db/transaction-isolation.conf b/.examples/docker-compose/with-nginx-proxy/mariadb/apache/db/transaction-isolation.conf
new file mode 100644
index 00000000..527a3f0e
--- /dev/null
+++ b/.examples/docker-compose/with-nginx-proxy/mariadb/apache/db/transaction-isolation.conf
@@ -0,0 +1,5 @@
+[mysqld]
+# Set Transaction isolation Level to READ-COMMITED (Required by nextcloud)
+# ================================================
+#   https://docs.nextcloud.com/server/13/admin_manual/configuration_database/linux_database_configuration.html#database-read-commited-transaction-isolation-level
+transaction-isolation = READ-COMMITTED
diff --git a/.examples/docker-compose/with-nginx-proxy/mariadb/apache/docker-compose.yml b/.examples/docker-compose/with-nginx-proxy/mariadb/apache/docker-compose.yml
index 45406dcb..738bdeb7 100644
--- a/.examples/docker-compose/with-nginx-proxy/mariadb/apache/docker-compose.yml
+++ b/.examples/docker-compose/with-nginx-proxy/mariadb/apache/docker-compose.yml
@@ -2,8 +2,7 @@ version: '3'
 
 services:
   db:
-    image: mariadb
-    # image: mysql
+    build: ./db
     restart: always
     volumes:
       - db:/var/lib/mysql
diff --git a/.examples/docker-compose/with-nginx-proxy/mariadb/fpm/db/Dockerfile b/.examples/docker-compose/with-nginx-proxy/mariadb/fpm/db/Dockerfile
new file mode 100644
index 00000000..d9a5cfb4
--- /dev/null
+++ b/.examples/docker-compose/with-nginx-proxy/mariadb/fpm/db/Dockerfile
@@ -0,0 +1,4 @@
+FROM mariadb
+#FROM mysql
+
+COPY transaction-isolation.conf /etc/mysql/conf.d/transaction-isolation.conf
diff --git a/.examples/docker-compose/with-nginx-proxy/mariadb/fpm/db/transaction-isolation.conf b/.examples/docker-compose/with-nginx-proxy/mariadb/fpm/db/transaction-isolation.conf
new file mode 100644
index 00000000..527a3f0e
--- /dev/null
+++ b/.examples/docker-compose/with-nginx-proxy/mariadb/fpm/db/transaction-isolation.conf
@@ -0,0 +1,5 @@
+[mysqld]
+# Set Transaction isolation Level to READ-COMMITED (Required by nextcloud)
+# ================================================
+#   https://docs.nextcloud.com/server/13/admin_manual/configuration_database/linux_database_configuration.html#database-read-commited-transaction-isolation-level
+transaction-isolation = READ-COMMITTED
diff --git a/.examples/docker-compose/with-nginx-proxy/mariadb/fpm/docker-compose.yml b/.examples/docker-compose/with-nginx-proxy/mariadb/fpm/docker-compose.yml
index 7417a665..fc1bdd60 100644
--- a/.examples/docker-compose/with-nginx-proxy/mariadb/fpm/docker-compose.yml
+++ b/.examples/docker-compose/with-nginx-proxy/mariadb/fpm/docker-compose.yml
@@ -2,8 +2,7 @@ version: '3'
 
 services:
   db:
-    image: mariadb
-    # image: mysql
+    build: ./db
     restart: always
     volumes:
       - db:/var/lib/mysql