diff --git a/application/Espo/Core/Utils/Database/Orm/Converter.php b/application/Espo/Core/Utils/Database/Orm/Converter.php
index 6f9a63a2cb..cb8df1d4ec 100644
--- a/application/Espo/Core/Utils/Database/Orm/Converter.php
+++ b/application/Espo/Core/Utils/Database/Orm/Converter.php
@@ -149,6 +149,10 @@ class Converter
                 $ormMetadata[$entityType]['skipRebuild'] = true;
             }
 
+            if ($entityMetadata['modifierClassName'] ?? null) {
+                $ormMetadata[$entityType]['modifierClassName'] = $entityMetadata['modifierClassName'];
+            }
+
             /** @var array<string, array<string, mixed>> $ormMetadata */
             $ormMetadata = Util::merge(
                 $ormMetadata,
diff --git a/application/Espo/Core/Utils/Database/Schema/Builder.php b/application/Espo/Core/Utils/Database/Schema/Builder.php
index 4d383955a5..bd5a483cef 100644
--- a/application/Espo/Core/Utils/Database/Schema/Builder.php
+++ b/application/Espo/Core/Utils/Database/Schema/Builder.php
@@ -29,6 +29,7 @@
 
 namespace Espo\Core\Utils\Database\Schema;
 
+use Espo\Core\InjectableFactory;
 use Espo\Core\Utils\Database\ConfigDataProvider;
 use Espo\Core\Utils\Database\MetadataProvider as MetadataProvider;
 use Espo\Core\Utils\File\Manager as FileManager;
@@ -50,6 +51,8 @@ use Doctrine\DBAL\Schema\Schema as DbalSchema;
 use Doctrine\DBAL\Types\Type as DbalType;
 use Espo\ORM\Type\AttributeType;
 
+use const E_USER_DEPRECATED;
+
 /**
  * Schema representation builder.
  */
@@ -70,6 +73,7 @@ class Builder
         private Metadata $metadata,
         private FileManager $fileManager,
         private Log $log,
+        private InjectableFactory $injectableFactory,
         private PathProvider $pathProvider,
         ConfigDataProvider $configDataProvider,
         ColumnPreparatorFactory $columnPreparatorFactory,
@@ -136,6 +140,14 @@ class Builder
 
         $entityType = $entityDefs->getName();
 
+        $modifier = $this->getEntityDefsModifier($entityDefs);
+
+        if ($modifier) {
+            $modifiedEntityDefs = $modifier->modify($entityDefs);
+
+            $entityDefs = EntityDefs::fromRaw($modifiedEntityDefs->toAssoc(), $entityType);
+        }
+
         $this->log->debug("Schema\Builder: Entity {$entityType}");
 
         $tableName = Util::toUnderScore($entityType);
@@ -196,6 +208,18 @@ class Builder
         $this->addIndexes($table, $entityDefs->getIndexList());
     }
 
+    private function getEntityDefsModifier(EntityDefs $entityDefs): ?EntityDefsModifier
+    {
+        /** @var ?class-string<EntityDefsModifier> $modifierClassName */
+        $modifierClassName = $entityDefs->getParam('modifierClassName');
+
+        if (!$modifierClassName) {
+            return null;
+        }
+
+        return $this->injectableFactory->create($modifierClassName);
+    }
+
     /**
      * @param array<string, mixed> $ormMeta
      * @param ?string[] $entityTypeList
@@ -464,6 +488,13 @@ class Builder
             $this->loadData($this->pathProvider->getCustom() . $this->tablesPath)
         );
 
+        if ($customTables !== []) {
+            trigger_error(
+                'Definitions in Database\\Schema\\tables are deprecated and will be remove in v8.0.',
+                E_USER_DEPRECATED
+            );
+        }
+
         return $customTables;
     }
 
diff --git a/application/Espo/Core/Utils/Database/Schema/tables/preferences.php b/application/Espo/Core/Utils/Database/Schema/EntityDefsModifier.php
similarity index 76%
rename from application/Espo/Core/Utils/Database/Schema/tables/preferences.php
rename to application/Espo/Core/Utils/Database/Schema/EntityDefsModifier.php
index 750a62c976..27ba9f710b 100644
--- a/application/Espo/Core/Utils/Database/Schema/tables/preferences.php
+++ b/application/Espo/Core/Utils/Database/Schema/EntityDefsModifier.php
@@ -27,24 +27,15 @@
  * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
  ************************************************************************/
 
-return [
-    'unset' => [
-        '__APPEND__',
-        'Preferences',
-    ],
-    'unsetIgnore' => [
-        '__APPEND__',
-        ['Preferences', 'fields', 'id'],
-        ['Preferences', 'fields', 'data'],
-    ],
-    'Preferences' => [
-        'fields' => [
-            'id' => [
-                'type' => 'id',
-            ],
-            'data' => [
-                'type' => 'text',
-            ]
-        ]
-    ],
-];
+namespace Espo\Core\Utils\Database\Schema;
+
+use Espo\Core\Utils\Database\Orm\Defs\EntityDefs;
+use Espo\ORM\Defs\EntityDefs as OrmEntityDefs;
+
+/**
+ * Modifies definitions before building a schema.
+ */
+interface EntityDefsModifier
+{
+    public function modify(OrmEntityDefs $entityDefs): EntityDefs;
+}
diff --git a/application/Espo/Core/Utils/Database/Schema/EntityDefsModifiers/JsonData.php b/application/Espo/Core/Utils/Database/Schema/EntityDefsModifiers/JsonData.php
new file mode 100644
index 0000000000..e054f1a065
--- /dev/null
+++ b/application/Espo/Core/Utils/Database/Schema/EntityDefsModifiers/JsonData.php
@@ -0,0 +1,68 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM - Open Source CRM application.
+ * Copyright (C) 2014-2023 Yurii Kuznietsov, Taras Machyshyn, Oleksii Avramenko
+ * Website: https://www.espocrm.com
+ *
+ * EspoCRM is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * EspoCRM is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with EspoCRM. If not, see http://www.gnu.org/licenses/.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Utils\Database\Schema\EntityDefsModifiers;
+
+use Espo\Core\Utils\Database\Orm\Defs\AttributeDefs;
+use Espo\Core\Utils\Database\Orm\Defs\EntityDefs;
+use Espo\Core\Utils\Database\Schema\EntityDefsModifier;
+use Espo\ORM\Defs\EntityDefs as OrmEntityDefs;
+use Espo\ORM\Type\AttributeType;
+
+/**
+ * A single JSON column instead of multiple field columns.
+ */
+class JsonData implements EntityDefsModifier
+{
+    public function modify(OrmEntityDefs $entityDefs): EntityDefs
+    {
+        $sourceIdAttribute = $entityDefs->getAttribute('id');
+
+        $idAttribute = AttributeDefs::create('id')
+            ->withType(AttributeType::ID);
+
+        $length = $sourceIdAttribute->getLength();
+        $dbType = $sourceIdAttribute->getParam('dbType');
+
+        if ($length) {
+            $idAttribute = $idAttribute->withLength($length);
+        }
+
+        if ($dbType) {
+            $idAttribute = $idAttribute->withDbType($dbType);
+        }
+
+        return EntityDefs::create()
+            ->withAttribute($idAttribute)
+            ->withAttribute(
+                AttributeDefs::create('data')
+                    ->withType(AttributeType::JSON_OBJECT)
+            );
+    }
+}
diff --git a/application/Espo/Resources/metadata/entityDefs/Preferences.json b/application/Espo/Resources/metadata/entityDefs/Preferences.json
index 983b59fa7b..b131b03511 100644
--- a/application/Espo/Resources/metadata/entityDefs/Preferences.json
+++ b/application/Espo/Resources/metadata/entityDefs/Preferences.json
@@ -186,5 +186,6 @@
             "default": false
         }
     },
-    "noDeletedAttribute": true
+    "noDeletedAttribute": true,
+    "modifierClassName": "Espo\\Core\\Utils\\Database\\Schema\\EntityDefsModifiers\\JsonData"
 }