... set_dbprefix(). Programatically set the prefix, great for multi-site systems that "namespace" with prefixes.
diff --git a/system/database/DB_active_rec.php b/system/database/DB_active_rec.php
index 7ddf20d..bc11ff4 100644
--- a/system/database/DB_active_rec.php
+++ b/system/database/DB_active_rec.php
@@ -1599,6 +1599,21 @@
 	// --------------------------------------------------------------------
 
 	/**
+	 * Set DB Prefix
+	 *
+	 * Set's the DB Prefix to something new without needing to reconnect
+	 *
+	 * @param	string	the prefix
+	 * @return	string
+	 */
+	public function set_dbprefix($prefix = '')
+	{
+		return $this->dbprefix = $prefix;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Track Aliases
 	 *
 	 * Used to track SQL statements written with aliased tables.