diff --git a/src/db/Capacitor.php b/src/db/Capacitor.php
index 7f321df..61ab4b4 100644
--- a/src/db/Capacitor.php
+++ b/src/db/Capacitor.php
@@ -3,6 +3,7 @@ namespace nur\sery\db;
 
 use nur\sery\php\func;
 use nur\sery\ValueException;
+use Traversable;
 
 /**
  * Class Capacitor: un objet permettant d'attaquer un canal spécifique d'une
@@ -140,7 +141,7 @@ class Capacitor implements ITransactor {
     return $this->storage->_charge($this->channel, $item, $func, $args, $values);
   }
 
-  function discharge(bool $reset=true): iterable {
+  function discharge(bool $reset=true): Traversable {
     return $this->storage->_discharge($this->channel, $reset);
   }
 
@@ -152,7 +153,7 @@ class Capacitor implements ITransactor {
     return $this->storage->_one($this->channel, $filter, $mergeQuery);
   }
 
-  function all($filter, ?array $mergeQuery=null): iterable {
+  function all($filter, ?array $mergeQuery=null): Traversable {
     return $this->storage->_all($this->channel, $filter, $mergeQuery);
   }
 
diff --git a/src/db/CapacitorChannel.php b/src/db/CapacitorChannel.php
index 94b360e..ca060f0 100644
--- a/src/db/CapacitorChannel.php
+++ b/src/db/CapacitorChannel.php
@@ -3,6 +3,7 @@ namespace nur\sery\db;
 
 use nur\sery\cl;
 use nur\sery\str;
+use Traversable;
 
 /**
  * Class CapacitorChannel: un canal d'une instance de {@link ICapacitor}
@@ -20,10 +21,19 @@ class CapacitorChannel {
 
   const EACH_COMMIT_THRESHOLD = 100;
 
+  /**
+   * @var bool faut-il passer par le cache pour les requêtes de each()
+   * ça peut être nécessaire avec MySQL/MariaDB si on utilise les requêtes non
+   * bufférisées, et que la fonction
+   */
+  const USE_CACHE = false;
+
   static function verifix_name(?string &$name, ?string &$tableName=null): void {
     if ($name !== null) {
       $name = strtolower($name);
-      if ($tableName === null) $tableName = "${name}_channel";
+      if ($tableName === null) {
+        $tableName = str_replace("-", "_", $tableName) . "_channel";
+      }
     } else {
       $name = static::class;
       if ($name === self::class) {
@@ -53,6 +63,7 @@ class CapacitorChannel {
     $this->tableName = $tableName;
     $this->manageTransactions = $manageTransactions ?? static::MANAGE_TRANSACTIONS;
     $this->eachCommitThreshold = self::verifix_eachCommitThreshold($eachCommitThreshold);
+    $this->useCache = static::USE_CACHE;
     $this->setup = false;
     $this->created = false;
     $columnDefinitions = cl::withn(static::COLUMN_DEFINITIONS);
@@ -122,6 +133,17 @@ class CapacitorChannel {
     return $this;
   }
 
+  protected bool $useCache;
+
+  function isUseCache(): bool {
+    return $this->useCache;
+  }
+
+  function setUseCache(bool $useCache=true): self {
+    $this->useCache = $useCache;
+    return $this;
+  }
+
   /**
    * initialiser ce channel avant sa première utilisation.
    */
@@ -358,7 +380,7 @@ class CapacitorChannel {
     return $this->capacitor->charge($item, $func, $args, $values);
   }
 
-  function discharge(bool $reset=true): iterable {
+  function discharge(bool $reset=true): Traversable {
     return $this->capacitor->discharge($reset);
   }
 
@@ -370,7 +392,7 @@ class CapacitorChannel {
     return $this->capacitor->one($filter, $mergeQuery);
   }
 
-  function all($filter, ?array $mergeQuery=null): iterable {
+  function all($filter, ?array $mergeQuery=null): Traversable {
     return $this->capacitor->all($filter, $mergeQuery);
   }
 
diff --git a/src/db/CapacitorStorage.php b/src/db/CapacitorStorage.php
index e61a891..576765f 100644
--- a/src/db/CapacitorStorage.php
+++ b/src/db/CapacitorStorage.php
@@ -2,8 +2,10 @@
 namespace nur\sery\db;
 
 use nur\sery\cl;
+use nur\sery\db\cache\cache;
 use nur\sery\php\func;
 use nur\sery\ValueException;
+use Traversable;
 
 /**
  * Class CapacitorStorage: objet permettant d'accumuler des données pour les
@@ -364,7 +366,7 @@ EOT;
   }
 
   /** décharger les données du canal spécifié */
-  function _discharge(CapacitorChannel $channel, bool $reset=true): iterable {
+  function _discharge(CapacitorChannel $channel, bool $reset=true): Traversable {
     $this->_create($channel);
     $rows = $this->db()->all([
       "select item__",
@@ -376,7 +378,7 @@ EOT;
     if ($reset) $this->_reset($channel);
   }
 
-  function discharge(?string $channel, bool $reset=true): iterable {
+  function discharge(?string $channel, bool $reset=true): Traversable {
     return $this->_discharge($this->getChannel($channel), $reset);
   }
 
@@ -452,12 +454,7 @@ EOT;
     return $this->_one($this->getChannel($channel), $filter, $mergeQuery);
   }
 
-  /**
-   * obtenir les lignes correspondant au filtre sur le canal spécifié
-   *
-   * si $filter n'est pas un tableau, il est transformé en ["id_" => $filter]
-   */
-  function _all(CapacitorChannel $channel, $filter, ?array $mergeQuery=null): iterable {
+  private function _allCached(string $id, CapacitorChannel $channel, $filter, ?array $mergeQuery=null): Traversable {
     $this->_create($channel);
     $this->verifixFilter($channel, $filter);
     $rows = $this->db()->all(cl::merge([
@@ -465,12 +462,28 @@ EOT;
       "from" => $channel->getTableName(),
       "where" => $filter,
     ], $mergeQuery), null, $this->getPrimaryKeys($channel));
+    if ($channel->isUseCache()) {
+      $cacheIds = [$id, get_class($channel)];
+      cache::get()->resetCached($cacheIds);
+      $rows = cache::new(null, $cacheIds, function() use ($rows) {
+        yield from $rows;
+      });
+    }
     foreach ($rows as $key => $row) {
       yield $key => $this->unserialize($channel, $row);
     }
   }
 
-  function all(?string $channel, $filter, $mergeQuery=null): iterable {
+  /**
+   * obtenir les lignes correspondant au filtre sur le canal spécifié
+   *
+   * si $filter n'est pas un tableau, il est transformé en ["id_" => $filter]
+   */
+  function _all(CapacitorChannel $channel, $filter, ?array $mergeQuery=null): Traversable {
+    return $this->_allCached("all", $channel, $filter, $mergeQuery);
+  }
+
+  function all(?string $channel, $filter, $mergeQuery=null): Traversable {
     return $this->_all($this->getChannel($channel), $filter, $mergeQuery);
   }
 
@@ -504,7 +517,8 @@ EOT;
     $tableName = $channel->getTableName();
     try {
       $args ??= [];
-      foreach ($this->_all($channel, $filter, $mergeQuery) as $values) {
+      $all = $this->_allCached("each", $channel, $filter, $mergeQuery);
+      foreach ($all as $values) {
         $rowIds = $this->getRowIds($channel, $values);
         $updates = func::_call($onEach, [$values["item"], $values, ...$args]);
         if (is_array($updates) && $updates) {
@@ -571,7 +585,8 @@ EOT;
     $tableName = $channel->getTableName();
     try {
       $args ??= [];
-      foreach ($this->_all($channel, $filter) as $values) {
+      $all = $this->_allCached("delete", $channel, $filter);
+      foreach ($all as $values) {
         $rowIds = $this->getRowIds($channel, $values);
         $delete = boolval(func::_call($onEach, [$values["item"], $values, ...$args]));
         if ($delete) {
diff --git a/src/db/cache/CacheChannel.php b/src/db/cache/CacheChannel.php
new file mode 100644
index 0000000..e7ed3e7
--- /dev/null
+++ b/src/db/cache/CacheChannel.php
@@ -0,0 +1,115 @@
+<?php
+namespace nur\sery\db\cache;
+
+use nur\sery\cl;
+use nur\sery\db\CapacitorChannel;
+use nur\sery\php\time\DateTime;
+use nur\sery\php\time\Delay;
+
+class CacheChannel extends CapacitorChannel {
+  /** @var int durée de vie par défaut du cache */
+  const DURATION = "1D"; // jusqu'au lendemain
+
+  const INCLUDES = null;
+
+  const EXCLUDES = null;
+
+  const COLUMN_DEFINITIONS = [
+    "group_id" => "varchar(64) not null",
+    "id" => "varchar(64) not null",
+    "date_start" => "datetime",
+    "duration_" => "text",
+    "primary key (group_id, id)",
+  ];
+
+  static function get_cache_ids($id): array {
+    if (is_array($id)) {
+      $keys = array_keys($id);
+      if (array_key_exists("group_id", $id)) $groupIdKey = "group_id";
+      else $groupIdKey = $keys[1] ?? null;
+      $groupId = $id[$groupIdKey] ?? "";
+      if (array_key_exists("id", $id)) $idKey = "id";
+      else $idKey = $keys[0] ?? null;
+      $id = $id[$idKey] ?? "";
+    } else {
+      $groupId = "";
+    }
+    if (preg_match('/^(.*\\\\)?([^\\\\]+)$/', $groupId, $ms)) {
+      # si le groupe est une classe, faire un hash du package pour limiter la
+      # longueur du groupe
+      [$package, $groupId] = [$ms[1], $ms[2]];
+      $package = substr(md5($package), 0, 4);
+      $groupId = "${groupId}_$package";
+    }
+    return ["group_id" => $groupId, "id" => $id];
+  }
+
+  function __construct(?string $duration=null, ?string $name=null) {
+    parent::__construct($name);
+    $this->duration = $duration ?? static::DURATION;
+    $this->includes = static::INCLUDES;
+    $this->excludes = static::EXCLUDES;
+  }
+
+  protected string $duration;
+
+  protected ?array $includes;
+
+  protected ?array $excludes;
+
+  function getItemValues($item): ?array {
+    return cl::merge(self::get_cache_ids($item), [
+      "item" => null,
+    ]);
+  }
+
+  function onCreate($item, array $values, ?array $alwaysNull, ?string $duration=null): ?array {
+    $now = new DateTime();
+    $duration ??= $this->duration;
+    return [
+      "date_start" => $now,
+      "duration" => new Delay($duration, $now),
+    ];
+  }
+
+  function onUpdate($item, array $values, array $pvalues, ?string $duration=null): ?array {
+    $now = new DateTime();
+    $duration ??= $this->duration;
+    return [
+      "date_start" => $now,
+      "duration" => new Delay($duration, $now),
+    ];
+  }
+
+  function shouldUpdate($cacheIds, bool $noCache=false): bool {
+    if ($noCache) return true;
+
+    $cacheIds = self::get_cache_ids($cacheIds);
+    $groupId = $cacheIds["group_id"];
+    if ($groupId) {
+      $includes = $this->includes;
+      $shouldInclude = $includes !== null && in_array($groupId, $includes);
+      $excludes = $this->excludes;
+      $shouldExclude = $excludes !== null && in_array($groupId, $excludes);
+      if (!$shouldInclude || $shouldExclude) return true;
+    }
+
+    $found = false;
+    $expired = false;
+    $this->each($cacheIds,
+      function($item, $values) use (&$found, &$expired) {
+        $found = true;
+        $expired = $values["duration"]->isElapsed();
+      });
+    return !$found || $expired;
+  }
+
+  function setCached($cacheIds, ?string $duration=null): void {
+    $this->charge($cacheIds, null, [$duration]);
+  }
+
+  function resetCached($cacheIds) {
+    $cacheIds = self::get_cache_ids($cacheIds);
+    $this->delete($cacheIds);
+  }
+}
diff --git a/src/db/cache/RowsChannel.php b/src/db/cache/RowsChannel.php
new file mode 100644
index 0000000..feaefff
--- /dev/null
+++ b/src/db/cache/RowsChannel.php
@@ -0,0 +1,51 @@
+<?php
+namespace nur\sery\db\cache;
+
+use Closure;
+use IteratorAggregate;
+use nur\sery\cl;
+use nur\sery\db\CapacitorChannel;
+use Traversable;
+
+class RowsChannel extends CapacitorChannel implements IteratorAggregate {
+  const COLUMN_DEFINITIONS = [
+    "key" => "varchar(128) primary key not null",
+    "all_values" => "mediumtext",
+  ];
+
+  function __construct($id, callable $builder, ?string $duration=null) {
+    $this->cacheIds = $cacheIds = CacheChannel::get_cache_ids($id);
+    $this->builder = Closure::fromCallable($builder);
+    $this->duration = $duration;
+    $name = "{$cacheIds["group_id"]}-{$cacheIds["id"]}";
+    parent::__construct($name);
+  }
+
+  protected array $cacheIds;
+
+  protected Closure $builder;
+
+  protected ?string $duration = null;
+
+  function getItemValues($item): ?array {
+    $key = array_keys($item)[0];
+    $row = $item[$key];
+    return [
+      "key" => $key,
+      "item" => $row,
+      "all_values" => implode(" ", cl::filter_n(cl::with($row))),
+    ];
+  }
+
+  function getIterator(): Traversable {
+    $cm = cache::get();
+    if ($cm->shouldUpdate($this->cacheIds)) {
+      $this->capacitor->reset();
+      foreach (($this->builder)() as $key => $row) {
+        $this->charge([$key => $row]);
+      }
+      $cm->setCached($this->cacheIds, $this->duration);
+    }
+    return $this->discharge(false);
+  }
+}
diff --git a/src/db/cache/cache.php b/src/db/cache/cache.php
new file mode 100644
index 0000000..d20fba2
--- /dev/null
+++ b/src/db/cache/cache.php
@@ -0,0 +1,37 @@
+<?php
+namespace nur\sery\db\cache;
+
+use nur\sery\db\Capacitor;
+use nur\sery\db\CapacitorStorage;
+use nur\sery\db\sqlite\SqliteStorage;
+
+class cache {
+  protected static ?CapacitorStorage $storage = null;
+
+  static function set_storage(CapacitorStorage $storage): CapacitorStorage {
+    return self::$storage = $storage;
+  }
+
+  protected static function get_storage(): CapacitorStorage {
+    return self::$storage ??= new SqliteStorage("");
+  }
+
+  protected static ?CacheChannel $channel = null;
+
+  static function set(?CacheChannel $channel): CacheChannel {
+    $channel ??= new CacheChannel();
+    new Capacitor(self::get_storage(), $channel);
+    return self::$channel = $channel;
+  }
+
+  static function get(): CacheChannel {
+    if (self::$channel !== null) return self::$channel;
+    else return self::set(null);
+  }
+
+  static function new(?RowsChannel $channel, $id=null, ?callable $builder=null): RowsChannel {
+    $channel ??= new RowsChannel($id, $builder);
+    new Capacitor(self::get_storage(), $channel);
+    return $channel;
+  }
+}
diff --git a/src/db/pdo/Pdo.php b/src/db/pdo/Pdo.php
index 3ce131c..d51c073 100644
--- a/src/db/pdo/Pdo.php
+++ b/src/db/pdo/Pdo.php
@@ -84,7 +84,7 @@ class Pdo implements IDatabase {
     # options
     $this->options = $params["options"] ?? static::OPTIONS;
     # configuration
-    $config = $params["replace_config"];
+    $config = $params["replace_config"] ?? null;
     if ($config === null) {
       $config = $params["config"] ?? static::CONFIG;
       if (is_callable($config)) $config = [$config];
diff --git a/src/db/sqlite/Sqlite.php b/src/db/sqlite/Sqlite.php
index 0a24859..ede6c95 100644
--- a/src/db/sqlite/Sqlite.php
+++ b/src/db/sqlite/Sqlite.php
@@ -97,7 +97,7 @@ class Sqlite implements IDatabase {
     $defaultAllowWal = static::ALLOW_WAL ?? !$inMemory;
     $this->allowWal = $params["allow_wal"] ?? $defaultAllowWal;
     # configuration
-    $config = $params["replace_config"];
+    $config = $params["replace_config"] ?? null;
     if ($config === null) {
       $config = $params["config"] ?? static::CONFIG;
       if (is_callable($config)) $config = [$config];