Mark OCI8Connection::getExecuteMode() internal

UPGRADE.md

@@ -4,6 +4,7 @@
 
 The non-interface methods of driver-level classes have been marked internal:
 
+- `OCI8Connection::getExecuteMode()`
 - `OCI8Statement::convertPositionalToNamedPlaceholders()`
 
 ## Inconsistently and ambiguously named driver-level classes are deprecated

lib/Doctrine/DBAL/Driver/OCI8/OCI8Connection.php

@@ -176,6 +176,8 @@ class OCI8Connection implements ConnectionInterface, ServerInfoAwareConnection
     /**
      * Returns the current execution mode.
      *
+     * @internal
+     *
      * @return int
      */
     public function getExecuteMode()