diff --git a/includes/YOURLS/Admin/Logger.php b/includes/YOURLS/Admin/Logger.php
index 40a6a04f..90ec6752 100644
--- a/includes/YOURLS/Admin/Logger.php
+++ b/includes/YOURLS/Admin/Logger.php
@@ -74,6 +74,10 @@ class Logger extends \Aura\Sql\Profiler {
      * @return strings     Readable SQL query with placeholders replaced
      */
     public function pretty_format($statement, array $values = array() ) {
+        if (!$values) {
+            return $statement;
+        }
+
         return preg_replace_callback(
             '/:([^\s;)]*)/',
             function ($matches) use ($values) {
diff --git a/includes/YOURLS/Database/YDB.php b/includes/YOURLS/Database/YDB.php
index 53b9f82e..2712fb0f 100644
--- a/includes/YOURLS/Database/YDB.php
+++ b/includes/YOURLS/Database/YDB.php
@@ -15,7 +15,7 @@ namespace YOURLS\Database;
 
 use YOURLS\Admin\Logger;
 use Aura\Sql\ExtendedPdo;
-
+use PDO;
 
 class YDB extends ExtendedPdo {
 
@@ -135,6 +135,29 @@ class YDB extends ExtendedPdo {
     }
 
 
+    // Infos (related to keyword) low level functions
+
+    public function set_infos($keyword, $infos) {
+        $this->info[$keyword] = $infos;
+    }
+
+    public function has_infos($keyword) {
+        return array_key_exists($keyword, $this->infos);
+    }
+
+    public function get_infos($keyword) {
+        return $this->infos[$keyword];
+    }
+
+    public function delete_infos($keyword) {
+        unset($this->infos[$keyword]);
+    }
+
+    /**
+     * @todo: infos & options are working the same way here. Abstract this.
+     */
+
+
     // Plugin low level functions, see functions-plugins.php
 
     public function get_plugins() {
@@ -222,7 +245,7 @@ class YDB extends ExtendedPdo {
     public function get_queries() {
         $queries = $this->getProfiler()->getProfiles();
 
-        if ($this->getAttribute(\PDO::ATTR_EMULATE_PREPARES)) {
+        if ($this->getAttribute(PDO::ATTR_EMULATE_PREPARES)) {
             // keep queries if $query['function'] != 'prepare'
             $queries = array_filter($queries, function($query) {return $query['function'] !== 'prepare';});
         }
@@ -266,7 +289,7 @@ class YDB extends ExtendedPdo {
      * @return string
      */
     public function mysql_version() {
-        $version = $this->pdo->getAttribute(\PDO::ATTR_SERVER_VERSION);
+        $version = $this->pdo->getAttribute(PDO::ATTR_SERVER_VERSION);
         return preg_replace('/(^[^0-9]*)|[^0-9.].*/', '', $version);
     }
 
@@ -284,28 +307,36 @@ class YDB extends ExtendedPdo {
         throw new \Exception\escape();
     }
 
-    public function get_col() {
-        //->fetchAll(PDO::FETCH_COLUMN) -> array
-        throw new \Exception\get_col();
+    public function get_col($query) {
+        yourls_deprecated_function( '$ydb->'.__FUNCTION__, '1.7.3', 'PDO' );
+        yourls_debug_log('LEGACY SQL: '.$query);
+        return $this->fetchCol($query);
     }
 
     public function get_results($query) {
+        yourls_deprecated_function( '$ydb->'.__FUNCTION__, '1.7.3', 'PDO' );
+        yourls_debug_log('LEGACY SQL: '.$query);
         $stm = parent::query($query);
-        return($stm->fetchAll(\PDO::FETCH_OBJ));
+        return($stm->fetchAll(PDO::FETCH_OBJ));
     }
 
-    public function get_row($sql) {
+    public function get_row($query) {
         yourls_deprecated_function( '$ydb->'.__FUNCTION__, '1.7.3', 'PDO' );
-        $row = $this->fetchObjects($sql);
+        yourls_debug_log('LEGACY SQL: '.$query);
+        $row = $this->fetchObjects($query);
         return $row[0];
     }
 
-    public function get_var() {
-        throw new \Exception\get_var();
+    public function get_var($query) {
+        yourls_deprecated_function( '$ydb->'.__FUNCTION__, '1.7.3', 'PDO' );
+        yourls_debug_log('LEGACY SQL: '.$query);
+        return $this->fetchValue($query);
     }
 
     public function query($query) {
-        throw new \Exception\query();
+        yourls_deprecated_function( '$ydb->'.__FUNCTION__, '1.7.3', 'PDO' );
+        yourls_debug_log('LEGACY SQL: '.$query);
+        return $this->fetchAffected($query);
     }
 
 }
diff --git a/includes/functions.php b/includes/functions.php
index f57c0fa0..4084904d 100644
--- a/includes/functions.php
+++ b/includes/functions.php
@@ -409,6 +409,7 @@ function yourls_keyword_is_taken( $keyword ) {
 	$keyword = yourls_escape( yourls_sanitize_keyword( $keyword ) );
 	$taken = false;
 	$table = YOURLS_DB_TABLE_URL;
+
 	$already_exists = $ydb->get_var( "SELECT COUNT(`keyword`) FROM `$table` WHERE `keyword` = '$keyword';" );
 	if ( $already_exists )
 		$taken = true;
@@ -436,8 +437,8 @@ function yourls_get_keyword_infos( $keyword, $use_cache = true ) {
 
 	yourls_do_action( 'pre_get_keyword', $keyword, $use_cache );
 
-	if( isset( $ydb->infos[$keyword] ) && $use_cache == true ) {
-		return yourls_apply_filter( 'get_keyword_infos', $ydb->infos[$keyword], $keyword );
+	if( $ydb->has_infos($keyword) && $use_cache == true ) {
+		return yourls_apply_filter( 'get_keyword_infos', $ydb->get_infos($keyword), $keyword );
 	}
 
 	yourls_do_action( 'get_keyword_not_cached', $keyword );
@@ -447,12 +448,12 @@ function yourls_get_keyword_infos( $keyword, $use_cache = true ) {
 
 	if( $infos ) {
 		$infos = (array)$infos;
-		$ydb->infos[ $keyword ] = $infos;
+		$ydb->set_infos($keyword, $infos);
 	} else {
-		$ydb->infos[ $keyword ] = false;
+		$ydb->set_infos($keyword, false);
 	}
 
-	return yourls_apply_filter( 'get_keyword_infos', $ydb->infos[$keyword], $keyword );
+	return yourls_apply_filter( 'get_keyword_infos', $infos, $keyword );
 }
 
 /**