diff --git a/src/db/pdo/Pdo.php b/src/db/pdo/Pdo.php
index 393a310..3ce131c 100644
--- a/src/db/pdo/Pdo.php
+++ b/src/db/pdo/Pdo.php
@@ -27,20 +27,28 @@ class Pdo implements IDatabase {
     }
   }
 
-  static function config_errmodeException_lowerCase(self $pdo) {
+  static function config_errmodeException_lowerCase(self $pdo): void {
     $pdo->db->setAttribute(\PDO::ATTR_ERRMODE, \PDO::ERRMODE_EXCEPTION);
     $pdo->db->setAttribute(\PDO::ATTR_CASE, \PDO::CASE_LOWER);
   }
+  const CONFIG_errmodeException_lowerCase = [self::class, "config_errmodeException_lowerCase"];
 
-  const OPTIONS = [
+  static function config_unbufferedQueries(self $pdo): void {
+    $pdo->db->setAttribute(\PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, false);
+  }
+  const CONFIG_unbufferedQueries = [self::class, "config_unbufferedQueries"];
+
+  protected const OPTIONS = [
     \PDO::ATTR_PERSISTENT => true,
   ];
 
-  const CONFIG = [
-    [self::class, "config_errmodeException_lowerCase"],
+  protected const DEFAULT_CONFIG = [
+    self::CONFIG_errmodeException_lowerCase,
   ];
 
-  const MIGRATE = null;
+  protected const CONFIG = null;
+
+  protected const MIGRATE = null;
 
   const dbconn_SCHEMA = [
     "name" => "string",
@@ -51,6 +59,7 @@ class Pdo implements IDatabase {
   const params_SCHEMA = [
     "dbconn" => ["array"],
     "options" => ["?array|callable"],
+    "replace_config" => ["?array|callable"],
     "config" => ["?array|callable"],
     "migrate" => ["?array|string|callable"],
     "auto_open" => ["bool", true],
@@ -75,7 +84,13 @@ class Pdo implements IDatabase {
     # options
     $this->options = $params["options"] ?? static::OPTIONS;
     # configuration
-    $this->config = $params["config"] ?? static::CONFIG;
+    $config = $params["replace_config"];
+    if ($config === null) {
+      $config = $params["config"] ?? static::CONFIG;
+      if (is_callable($config)) $config = [$config];
+      $config = cl::merge(static::DEFAULT_CONFIG, $config);
+    }
+    $this->config = $config;
     # migrations
     $this->migration = $params["migrate"] ?? static::MIGRATE;
     #
diff --git a/src/db/sqlite/Sqlite.php b/src/db/sqlite/Sqlite.php
index 63bd943..0a24859 100644
--- a/src/db/sqlite/Sqlite.php
+++ b/src/db/sqlite/Sqlite.php
@@ -38,31 +38,36 @@ class Sqlite implements IDatabase {
   static function config_enableExceptions(self $sqlite): void {
     $sqlite->db->enableExceptions(true);
   }
+  const CONFIG_enableExceptions = [self::class, "config_enableExceptions"];
 
   /**
    * @var int temps maximum à attendre que la base soit accessible si elle est
    * verrouillée
    */
-  const BUSY_TIMEOUT = 30 * 1000;
+  protected const BUSY_TIMEOUT = 30 * 1000;
 
   static function config_busyTimeout(self $sqlite): void {
     $sqlite->db->busyTimeout(static::BUSY_TIMEOUT);
   }
+  const CONFIG_busyTimeout = [self::class, "config_busyTimeout"];
 
   static function config_enableWalIfAllowed(self $sqlite): void {
     if ($sqlite->isWalAllowed()) {
       $sqlite->db->exec("PRAGMA journal_mode=WAL");
     }
   }
+  const CONFIG_enableWalIfAllowed = [self::class, "config_enableWalIfAllowed"];
 
   const ALLOW_WAL = null;
 
-  const CONFIG = [
-    [self::class, "config_enableExceptions"],
-    [self::class, "config_busyTimeout"],
-    [self::class, "config_enableWalIfAllowed"],
+  const DEFAULT_CONFIG = [
+    self::CONFIG_enableExceptions,
+    self::CONFIG_busyTimeout,
+    self::CONFIG_enableWalIfAllowed,
   ];
 
+  const CONFIG = null;
+
   const MIGRATE = null;
 
   const params_SCHEMA = [
@@ -70,6 +75,7 @@ class Sqlite implements IDatabase {
     "flags" => ["int", SQLITE3_OPEN_READWRITE + SQLITE3_OPEN_CREATE],
     "encryption_key" => ["string", ""],
     "allow_wal" => ["?bool"],
+    "replace_config" => ["?array|callable"],
     "config" => ["?array|callable"],
     "migrate" => ["?array|string|callable"],
     "auto_open" => ["bool", true],
@@ -91,7 +97,13 @@ class Sqlite implements IDatabase {
     $defaultAllowWal = static::ALLOW_WAL ?? !$inMemory;
     $this->allowWal = $params["allow_wal"] ?? $defaultAllowWal;
     # configuration
-    $this->config = $params["config"] ?? static::CONFIG;
+    $config = $params["replace_config"];
+    if ($config === null) {
+      $config = $params["config"] ?? static::CONFIG;
+      if (is_callable($config)) $config = [$config];
+      $config = cl::merge(static::DEFAULT_CONFIG, $config);
+    }
+    $this->config = $config;
     # migrations
     $this->migration = $params["migrate"] ?? static::MIGRATE;
     #