diff --git a/application/Espo/Core/Select/Where/ItemGeneralConverter.php b/application/Espo/Core/Select/Where/ItemGeneralConverter.php
index 504a917ed9..aa5d468e7d 100644
--- a/application/Espo/Core/Select/Where/ItemGeneralConverter.php
+++ b/application/Espo/Core/Select/Where/ItemGeneralConverter.php
@@ -38,6 +38,8 @@ use Espo\Entities\ArrayValue;
 use Espo\Entities\User;
 use Espo\ORM\Defs as ORMDefs;
 use Espo\ORM\Entity;
+use Espo\ORM\Query\Part\Condition as Cond;
+use Espo\ORM\Query\Part\Join;
 use Espo\ORM\Query\Part\WhereClause;
 use Espo\ORM\Query\Part\WhereItem as WhereClauseItem;
 use Espo\ORM\Query\SelectBuilder as QueryBuilder;
@@ -1319,9 +1321,11 @@ class ItemGeneralConverter implements ItemConverter
 
         if ($relationType == Entity::MANY_MANY) {
             $key = $defs->getForeignMidKey();
+
             $nearKey = $defs->getMidKey();
             $middleEntityType = ucfirst($defs->getRelationshipName());
 
+            // IN-sub-query performs faster than EXISTS on MariaDB when multiple IDs.
             // Left-join performs faster than Inner-join.
             // Not joining a foreign table as it affects performance in MySQL.
             $subQuery = QueryBuilder::create()
@@ -1385,20 +1389,26 @@ class ItemGeneralConverter implements ItemConverter
 
         if ($relationType == Entity::MANY_MANY) {
             $key = $defs->getForeignMidKey();
-            $nearKey = $defs->getMidKey();
-            $middleEntityType = ucfirst($defs->getRelationshipName());
 
-            $subQuery = QueryBuilder::create()
-                ->select('id')
-                ->from($this->entityType)
-                ->leftJoin($middleEntityType, $alias, [
-                    "{$alias}.{$nearKey}:" => 'id',
-                    "{$alias}.deleted" => false,
-                ])
-                ->where(["{$alias}.{$key}=" => $value])
-                ->build();
-
-            return ['id!=s' =>  $subQuery->getRaw()];
+            // MariaDB and MySQL performs slow, PostgreSQL – fast.
+            return Cond::not(
+                Cond::exists(
+                    QueryBuilder::create()
+                        ->from($this->entityType, 'sq')
+                        ->join(
+                            Join::create($link, $alias)
+                                ->withOnlyMiddle()
+                        )
+                        ->where(["{$alias}.{$key}" => $value])
+                        ->where(
+                            Cond::equal(
+                                Cond::column('sq.id'),
+                                Cond::column(lcfirst($this->entityType) . '.id')
+                            )
+                        )
+                        ->build()
+                )
+            )->getRaw();
         }
 
         if (
@@ -1455,6 +1465,7 @@ class ItemGeneralConverter implements ItemConverter
             $whereList = [];
 
             foreach ($value as $targetId) {
+                // Only-middle join performs slower on MariaDB.
                 $sq = QueryBuilder::create()
                     ->from($this->entityType)
                     ->select('id')
diff --git a/application/Espo/ORM/Query/Part/Join.php b/application/Espo/ORM/Query/Part/Join.php
index b80893870c..0bd38d98fb 100644
--- a/application/Espo/ORM/Query/Part/Join.php
+++ b/application/Espo/ORM/Query/Part/Join.php
@@ -41,6 +41,7 @@ class Join
     private string $target;
     private ?string $alias = null;
     private ?WhereItem $conditions = null;
+    private bool $onlyMiddle = false;
 
     private function __construct(string $target, ?string $alias = null)
     {
@@ -87,6 +88,11 @@ class Join
         return !$this->isTable();
     }
 
+    public function isOnlyMiddle(): bool
+    {
+        return $this->onlyMiddle;
+    }
+
     /**
      * Create.
      *
@@ -137,4 +143,15 @@ class Join
 
         return $obj;
     }
+
+    /**
+     * Join only middle table. For many-to-many relationships.
+     */
+    public function withOnlyMiddle(bool $onlyMiddle = true): self
+    {
+        $obj = clone $this;
+        $obj->onlyMiddle = $onlyMiddle;
+
+        return $obj;
+    }
 }
diff --git a/application/Espo/ORM/Query/SelectingBuilderTrait.php b/application/Espo/ORM/Query/SelectingBuilderTrait.php
index 1102764740..52a576fb65 100644
--- a/application/Espo/ORM/Query/SelectingBuilderTrait.php
+++ b/application/Espo/ORM/Query/SelectingBuilderTrait.php
@@ -184,15 +184,18 @@ trait SelectingBuilderTrait
      * @param Join|string $target
      * A relation name or table. A relation name should be in camelCase, a table in CamelCase.
      * @param string|null $alias An alias.
-     * @param WhereItem|array<mixed, mixed>|null $conditions Join conditions.
+     * @param WhereItem|array<string|int, mixed>|null $conditions Join conditions.
      *
      * @todo Support USE INDEX in Join.
      */
     private function joinInternal(string $type, $target, ?string $alias = null, $conditions = null): self
     {
+        $onlyMiddle = false;
+
         if ($target instanceof Join) {
             $alias = $alias ?? $target->getAlias();
             $conditions = $conditions ?? $target->getConditions();
+            $onlyMiddle = $target->isOnlyMiddle();
             $target = $target->getTarget();
         }
 
@@ -229,6 +232,22 @@ trait SelectingBuilderTrait
             return $this;
         }
 
+        $params = [];
+
+        if ($noLeftAlias) {
+            $params['noLeftAlias'] = true;
+        }
+
+        if ($onlyMiddle) {
+            $params['onlyMiddle'] = true;
+        }
+
+        if ($params !== []) {
+            $this->params[$type][] = [$target, $alias, $conditions, $params];
+
+            return $this;
+        }
+
         if (is_null($alias) && is_null($conditions)) {
             $this->params[$type][] = $target;
 
@@ -241,13 +260,7 @@ trait SelectingBuilderTrait
             return $this;
         }
 
-        $item = [$target, $alias, $conditions];
-
-        if ($noLeftAlias) {
-            $item[] = ['noLeftAlias' => true];
-        }
-
-        $this->params[$type][] = $item;
+        $this->params[$type][] = [$target, $alias, $conditions];
 
         return $this;
     }
diff --git a/application/Espo/ORM/QueryComposer/BaseQueryComposer.php b/application/Espo/ORM/QueryComposer/BaseQueryComposer.php
index 7900d5bc7d..72727678af 100644
--- a/application/Espo/ORM/QueryComposer/BaseQueryComposer.php
+++ b/application/Espo/ORM/QueryComposer/BaseQueryComposer.php
@@ -3274,7 +3274,11 @@ abstract class BaseQueryComposer implements QueryComposer
 
                 $distantTable = $this->toDb($foreignEntityType);
 
-                $midAlias = $alias . 'Middle';
+                $onlyMiddle = $joinParams['onlyMiddle'] ?? false;
+
+                $midAlias = $onlyMiddle ?
+                    $alias :
+                    $alias . 'Middle';
 
                 $indexKeyList = null;
                 $indexList = $joinParams['useIndex'] ?? null;
@@ -3339,8 +3343,6 @@ abstract class BaseQueryComposer implements QueryComposer
                     $sql .= " AND " . implode(" AND ", $joinSqlList);
                 }
 
-                $onlyMiddle = $joinParams['onlyMiddle'] ?? false;
-
                 if (!$onlyMiddle) {
                     $rightKeyColumn = $this->quoteColumn("{$alias}." . $this->toDb($foreignKey));
                     $middleDistantKeyColumn = $this->quoteColumn("{$midAlias}." . $this->toDb($distantKey));
diff --git a/tests/unit/Espo/ORM/MysqlQueryComposerTest.php b/tests/unit/Espo/ORM/MysqlQueryComposerTest.php
index 8c9fa5c48e..ba6e0e22b5 100644
--- a/tests/unit/Espo/ORM/MysqlQueryComposerTest.php
+++ b/tests/unit/Espo/ORM/MysqlQueryComposerTest.php
@@ -954,7 +954,7 @@ class MysqlQueryComposerTest extends \PHPUnit\Framework\TestCase
 
         $expectedSql =
             "SELECT post.id AS `id` FROM `post` " .
-            "LEFT JOIN `post_tag` AS `tagsMiddle` ON post.id = tagsMiddle.post_id AND tagsMiddle.deleted = 0 " .
+            "LEFT JOIN `post_tag` AS `tags` ON post.id = tags.post_id AND tags.deleted = 0 " .
             "WHERE post.deleted = 0";
 
         $this->assertEquals($expectedSql, $sql);