diff --git a/phpBB/phpbb/db/tools.php b/phpBB/phpbb/db/tools.php
index c8d25f23a2..ee2b6e843b 100644
--- a/phpBB/phpbb/db/tools.php
+++ b/phpBB/phpbb/db/tools.php
@@ -17,7 +17,7 @@ namespace phpbb\db;
 * Database Tools for handling cross-db actions such as altering columns, etc.
 * Currently not supported is returning SQL for creating tables.
 */
-class tools
+class tools implements tools_interface
 {
 	/**
 	* Current sql layer
@@ -1081,11 +1081,11 @@ class tools
 	/**
 	* Gets a list of columns of a table.
 	*
-	* @param string $table		Table name
+	* @param string $table_name		Table name
 	*
 	* @return array				Array of column names (all lower case)
 	*/
-	function sql_list_columns($table)
+	function sql_list_columns($table_name)
 	{
 		$columns = array();
 
@@ -1093,7 +1093,7 @@ class tools
 		{
 			case 'mysql_40':
 			case 'mysql_41':
-				$sql = "SHOW COLUMNS FROM $table";
+				$sql = "SHOW COLUMNS FROM $table_name";
 			break;
 
 			// PostgreSQL has a way of doing this in a much simpler way but would
@@ -1101,7 +1101,7 @@ class tools
 			case 'postgres':
 				$sql = "SELECT a.attname
 					FROM pg_class c, pg_attribute a
-					WHERE c.relname = '{$table}'
+					WHERE c.relname = '{$table_name}'
 						AND a.attnum > 0
 						AND a.attrelid = c.oid";
 			break;
@@ -1113,13 +1113,13 @@ class tools
 				$sql = "SELECT c.name
 					FROM syscolumns c
 					LEFT JOIN sysobjects o ON c.id = o.id
-					WHERE o.name = '{$table}'";
+					WHERE o.name = '{$table_name}'";
 			break;
 
 			case 'oracle':
 				$sql = "SELECT column_name
 					FROM user_tab_columns
-					WHERE LOWER(table_name) = '" . strtolower($table) . "'";
+					WHERE LOWER(table_name) = '" . strtolower($table_name) . "'";
 			break;
 
 			case 'sqlite':
@@ -1127,7 +1127,7 @@ class tools
 				$sql = "SELECT sql
 					FROM sqlite_master
 					WHERE type = 'table'
-						AND name = '{$table}'";
+						AND name = '{$table_name}'";
 
 				$result = $this->db->sql_query($sql);
 
@@ -1175,14 +1175,14 @@ class tools
 	/**
 	* Check whether a specified column exist in a table
 	*
-	* @param string	$table			Table to check
+	* @param string	$table_name		Table to check
 	* @param string	$column_name	Column to check
 	*
 	* @return bool		True if column exists, false otherwise
 	*/
-	function sql_column_exists($table, $column_name)
+	function sql_column_exists($table_name, $column_name)
 	{
-		$columns = $this->sql_list_columns($table);
+		$columns = $this->sql_list_columns($table_name);
 
 		return isset($columns[$column_name]);
 	}
diff --git a/phpBB/phpbb/db/tools_interface.php b/phpBB/phpbb/db/tools_interface.php
new file mode 100644
index 0000000000..d0ecac779e
--- /dev/null
+++ b/phpBB/phpbb/db/tools_interface.php
@@ -0,0 +1,202 @@
+<?php
+/**
+*
+* This file is part of the phpBB Forum Software package.
+*
+* @copyright (c) phpBB Limited <https://www.phpbb.com>
+* @license GNU General Public License, version 2 (GPL-2.0)
+*
+* For full copyright and license information, please see
+* the docs/CREDITS.txt file.
+*
+*/
+
+namespace phpbb\db;
+
+/**
+ * Interface for a Database Tools for handling cross-db actions such as altering columns, etc.
+ */
+interface tools_interface
+{
+	/**
+	 * Handle passed database update array.
+	 * Expected structure...
+	 * Key being one of the following
+	 *	drop_tables: Drop tables
+	 *	add_tables: Add tables
+	 *	change_columns: Column changes (only type, not name)
+	 *	add_columns: Add columns to a table
+	 *	drop_keys: Dropping keys
+	 *	drop_columns: Removing/Dropping columns
+	 *	add_primary_keys: adding primary keys
+	 *	add_unique_index: adding an unique index
+	 *	add_index: adding an index (can be column:index_size if you need to provide size)
+	 *
+	 * The values are in this format:
+	 *		{TABLE NAME}		=> array(
+	 *			{COLUMN NAME}		=> array({COLUMN TYPE}, {DEFAULT VALUE}, {OPTIONAL VARIABLES}),
+	 *			{KEY/INDEX NAME}	=> array({COLUMN NAMES}),
+	 *		)
+	 *
+	 *
+	 * @param array $schema_changes
+	 * @return null
+	 */
+	public function perform_schema_changes($schema_changes);
+
+	/**
+	 * Gets a list of tables in the database.
+	 *
+	 * @return array		Array of table names  (all lower case)
+	 */
+	public function sql_list_tables();
+
+	/**
+	 * Check if table exists
+	 *
+	 * @param string	$table_name	The table name to check for
+	 * @return bool true if table exists, else false
+	 */
+	public function sql_table_exists($table_name);
+
+	/**
+	 * Create SQL Table
+	 *
+	 * @param string	$table_name		The table name to create
+	 * @param array		$table_data		Array containing table data.
+	 * @return array|true	Statements to run, or true if the statements have been executed
+	 */
+	public function sql_create_table($table_name, $table_data);
+
+	/**
+	 * Drop Table
+	 *
+	 * @param string	$table_name		The table name to drop
+	 * @return array|true	Statements to run, or true if the statements have been executed
+	 */
+	public function sql_table_drop($table_name);
+
+	/**
+	 * Gets a list of columns of a table.
+	 *
+	 * @param string $table_name	Table name
+	 * @return array		Array of column names (all lower case)
+	 */
+	public function sql_list_columns($table_name);
+
+	/**
+	 * Check whether a specified column exist in a table
+	 *
+	 * @param string	$table_name		Table to check
+	 * @param string	$column_name	Column to check
+	 * @return bool		True if column exists, false otherwise
+	 */
+	public function sql_column_exists($table_name, $column_name);
+
+	/**
+	 * Add new column
+	 *
+	 * @param string	$table_name		Table to modify
+	 * @param string	$column_name	Name of the column to add
+	 * @param array		$column_data	Column data
+	 * @param bool		$inline			Whether the query should actually be run,
+	 *						or return a string for adding the column
+	 * @return array|true	Statements to run, or true if the statements have been executed
+	 */
+	public function sql_column_add($table_name, $column_name, $column_data, $inline = false);
+
+	/**
+	 * Change column type (not name!)
+	 *
+	 * @param string	$table_name		Table to modify
+	 * @param string	$column_name	Name of the column to modify
+	 * @param array		$column_data	Column data
+	 * @param bool		$inline			Whether the query should actually be run,
+	 *						or return a string for modifying the column
+	 * @return array|true	Statements to run, or true if the statements have been executed
+	 */
+	public function sql_column_change($table_name, $column_name, $column_data, $inline = false);
+
+	/**
+	 * Drop column
+	 *
+	 * @param string	$table_name		Table to modify
+	 * @param string	$column_name	Name of the column to drop
+	 * @param bool		$inline			Whether the query should actually be run,
+	 *						or return a string for deleting the column
+	 * @return array|true	Statements to run, or true if the statements have been executed
+	 */
+	public function sql_column_remove($table_name, $column_name, $inline = false);
+
+	/**
+	 * List all of the indices that belong to a table
+	 *
+	 * NOTE: does not list
+	 * - UNIQUE indices
+	 * - PRIMARY keys
+	 *
+	 * @param string	$table_name		Table to check
+	 * @return array		Array with index names
+	 */
+	public function sql_list_index($table_name);
+
+	/**
+	 * Check if a specified index exists in table. Does not return PRIMARY KEY and UNIQUE indexes.
+	 *
+	 * @param string	$table_name		Table to check the index at
+	 * @param string	$index_name		The index name to check
+	 * @return bool			True if index exists, else false
+	 */
+	public function sql_index_exists($table_name, $index_name);
+
+	/**
+	 * Add index
+	 *
+	 * @param string	$table_name		Table to modify
+	 * @param string	$index_name		Name of the index to create
+	 * @param string|array	$column		Either a string with a column name, or an array with columns
+	 * @return array|true	Statements to run, or true if the statements have been executed
+	 */
+	public function sql_create_index($table_name, $index_name, $column);
+
+	/**
+	 * Drop Index
+	 *
+	 * @param string	$table_name		Table to modify
+	 * @param string	$index_name		Name of the index to delete
+	 * @return array|true	Statements to run, or true if the statements have been executed
+	 */
+	public function sql_index_drop($table_name, $index_name);
+
+	/**
+	 * Check if a specified index exists in table.
+	 *
+	 * NOTE: Does not return normal and PRIMARY KEY indexes
+	 *
+	 * @param string	$table_name		Table to check the index at
+	 * @param string	$index_name		The index name to check
+	 * @return bool True if index exists, else false
+	 */
+	public function sql_unique_index_exists($table_name, $index_name);
+
+	/**
+	 * Add unique index
+	 *
+	 * @param string	$table_name		Table to modify
+	 * @param string	$index_name		Name of the unique index to create
+	 * @param string|array	$column		Either a string with a column name, or an array with columns
+	 * @return array|true	Statements to run, or true if the statements have been executed
+	 */
+	public function sql_create_unique_index($table_name, $index_name, $column);
+
+	/**
+	 * Add primary key
+	 *
+	 * @param string	$table_name		Table to modify
+	 * @param string|array	$column		Either a string with a column name, or an array with columns
+	 * @param bool		$inline			Whether the query should actually be run,
+	 *						or return a string for creating the key
+	 * @return array|true	Statements to run, or true if the statements have been executed
+	 */
+	public function sql_create_primary_key($table_name, $column, $inline = false);
+}