diff --git a/src/Database/Adapter.php b/src/Database/Adapter.php
index 7a629c695..1a9770085 100644
--- a/src/Database/Adapter.php
+++ b/src/Database/Adapter.php
@@ -979,6 +979,13 @@ abstract public function getSupportForIndexArray(): bool;
      */
     abstract public function getSupportForCastIndexArray(): bool;
 
+    /**
+     * Does the adapter use GIN indexes for array columns?
+     *
+     * @return bool
+     */
+    abstract public function getSupportForGinIndex(): bool;
+
     /**
      * Is unique index supported?
      *
diff --git a/src/Database/Adapter/MariaDB.php b/src/Database/Adapter/MariaDB.php
index 1bd8797c9..2e45a0c38 100644
--- a/src/Database/Adapter/MariaDB.php
+++ b/src/Database/Adapter/MariaDB.php
@@ -1684,7 +1684,7 @@ protected function getSQLType(string $type, int $size, bool $signed = true, bool
             return $this->getSpatialSQLType($type, $required);
         }
         if ($array === true) {
-            return 'JSON';
+            return 'JSON NOT NULL DEFAULT (JSON_ARRAY())';
         }
 
         switch ($type) {
@@ -2082,12 +2082,12 @@ protected function getOperatorSQL(string $column, Operator $operator, int &$bind
             case Operator::TYPE_ARRAY_APPEND:
                 $bindKey = "op_{$bindIndex}";
                 $bindIndex++;
-                return "{$quotedColumn} = JSON_MERGE_PRESERVE(IFNULL({$quotedColumn}, JSON_ARRAY()), :$bindKey)";
+                return "{$quotedColumn} = JSON_MERGE_PRESERVE({$quotedColumn}, :$bindKey)";
 
             case Operator::TYPE_ARRAY_PREPEND:
                 $bindKey = "op_{$bindIndex}";
                 $bindIndex++;
-                return "{$quotedColumn} = JSON_MERGE_PRESERVE(:$bindKey, IFNULL({$quotedColumn}, JSON_ARRAY()))";
+                return "{$quotedColumn} = JSON_MERGE_PRESERVE(:$bindKey, {$quotedColumn})";
 
             case Operator::TYPE_ARRAY_INSERT:
                 $indexKey = "op_{$bindIndex}";
diff --git a/src/Database/Adapter/Mongo.php b/src/Database/Adapter/Mongo.php
index 52acc9541..b5bae1d05 100644
--- a/src/Database/Adapter/Mongo.php
+++ b/src/Database/Adapter/Mongo.php
@@ -3221,6 +3221,11 @@ public function getSupportForCastIndexArray(): bool
         return false;
     }
 
+    public function getSupportForGinIndex(): bool
+    {
+        return false;
+    }
+
     public function getSupportForUpserts(): bool
     {
         return true;
diff --git a/src/Database/Adapter/Pool.php b/src/Database/Adapter/Pool.php
index 3128d97ed..36784870f 100644
--- a/src/Database/Adapter/Pool.php
+++ b/src/Database/Adapter/Pool.php
@@ -388,6 +388,11 @@ public function getSupportForCastIndexArray(): bool
         return $this->delegate(__FUNCTION__, \func_get_args());
     }
 
+    public function getSupportForGinIndex(): bool
+    {
+        return $this->delegate(__FUNCTION__, \func_get_args());
+    }
+
     public function getSupportForUniqueIndex(): bool
     {
         return $this->delegate(__FUNCTION__, \func_get_args());
diff --git a/src/Database/Adapter/Postgres.php b/src/Database/Adapter/Postgres.php
index 2af11aea3..c11823675 100644
--- a/src/Database/Adapter/Postgres.php
+++ b/src/Database/Adapter/Postgres.php
@@ -892,6 +892,26 @@ public function createIndex(string $collection, string $id, string $type, array
         $collection = $this->filter($collection);
         $id = $this->filter($id);
 
+        // JSONB array columns need GIN indexes for containment queries (@>).
+        $isArrayIndex = false;
+        if ($type === Database::INDEX_KEY) {
+            $metadataCollection = new Document(['$id' => Database::METADATA]);
+            $collectionDoc = $this->getDocument($metadataCollection, $collection);
+            if (!$collectionDoc->isEmpty()) {
+                $collectionAttributes = \json_decode($collectionDoc->getAttribute('attributes', '[]'), true);
+                $arrayCount = 0;
+                foreach ($attributes as $attr) {
+                    foreach ($collectionAttributes as $collectionAttribute) {
+                        if (\strtolower($collectionAttribute['$id']) === \strtolower($attr) && !empty($collectionAttribute['array'])) {
+                            $arrayCount++;
+                            break;
+                        }
+                    }
+                }
+                $isArrayIndex = $arrayCount > 0 && $arrayCount === \count($attributes);
+            }
+        }
+
         foreach ($attributes as $i => $attr) {
             $order = empty($orders[$i]) || Database::INDEX_FULLTEXT === $type ? '' : $orders[$i];
             $isNestedPath = isset($indexAttributeTypes[$attr]) && \str_contains($attr, '.') && $indexAttributeTypes[$attr] === Database::VAR_OBJECT;
@@ -933,13 +953,13 @@ public function createIndex(string $collection, string $id, string $type, array
         $sql = "CREATE {$sqlType} \"{$keyName}\" ON {$this->getSQLTable($collection)}";
 
         // Add USING clause for special index types
-        $sql .= match ($type) {
-            Database::INDEX_SPATIAL => " USING GIST ({$attributes})",
-            Database::INDEX_HNSW_EUCLIDEAN => " USING HNSW ({$attributes} vector_l2_ops)",
-            Database::INDEX_HNSW_COSINE => " USING HNSW ({$attributes} vector_cosine_ops)",
-            Database::INDEX_HNSW_DOT => " USING HNSW ({$attributes} vector_ip_ops)",
-            Database::INDEX_OBJECT => " USING GIN ({$attributes})",
-            Database::INDEX_TRIGRAM =>
+        $sql .= match (true) {
+            $type === Database::INDEX_SPATIAL => " USING GIST ({$attributes})",
+            $type === Database::INDEX_HNSW_EUCLIDEAN => " USING HNSW ({$attributes} vector_l2_ops)",
+            $type === Database::INDEX_HNSW_COSINE => " USING HNSW ({$attributes} vector_cosine_ops)",
+            $type === Database::INDEX_HNSW_DOT => " USING HNSW ({$attributes} vector_ip_ops)",
+            $type === Database::INDEX_OBJECT, $isArrayIndex => " USING GIN ({$attributes})",
+            $type === Database::INDEX_TRIGRAM =>
                 " USING GIN (" . implode(', ', array_map(
                     fn ($attr) => "$attr gin_trgm_ops",
                     array_map(fn ($attr) => trim($attr), explode(',', $attributes))
@@ -1937,7 +1957,7 @@ protected function getFulltextValue(string $value): string
     protected function getSQLType(string $type, int $size, bool $signed = true, bool $array = false, bool $required = false): string
     {
         if ($array === true) {
-            return 'JSONB';
+            return "JSONB NOT NULL DEFAULT '[]'::jsonb";
         }
 
         switch ($type) {
@@ -2117,6 +2137,16 @@ public function getSupportForTimeouts(): bool
         return true;
     }
 
+    public function getSupportForCastIndexArray(): bool
+    {
+        return true;
+    }
+
+    public function getSupportForGinIndex(): bool
+    {
+        return true;
+    }
+
     /**
      * Does the adapter handle Query Array Overlaps?
      *
@@ -2688,12 +2718,12 @@ protected function getOperatorSQL(string $column, Operator $operator, int &$bind
             case Operator::TYPE_ARRAY_APPEND:
                 $bindKey = "op_{$bindIndex}";
                 $bindIndex++;
-                return "{$quotedColumn} = COALESCE({$columnRef}, '[]'::jsonb) || :$bindKey::jsonb";
+                return "{$quotedColumn} = {$columnRef} || :$bindKey::jsonb";
 
             case Operator::TYPE_ARRAY_PREPEND:
                 $bindKey = "op_{$bindIndex}";
                 $bindIndex++;
-                return "{$quotedColumn} = :$bindKey::jsonb || COALESCE({$columnRef}, '[]'::jsonb)";
+                return "{$quotedColumn} = :$bindKey::jsonb || {$columnRef}";
 
             case Operator::TYPE_ARRAY_UNIQUE:
                 return "{$quotedColumn} = COALESCE((
diff --git a/src/Database/Adapter/SQL.php b/src/Database/Adapter/SQL.php
index 702c1ea2a..7a82ee202 100644
--- a/src/Database/Adapter/SQL.php
+++ b/src/Database/Adapter/SQL.php
@@ -1545,6 +1545,11 @@ public function getSupportForCastIndexArray(): bool
         return false;
     }
 
+    public function getSupportForGinIndex(): bool
+    {
+        return false;
+    }
+
     public function getSupportForRelationships(): bool
     {
         return true;
@@ -2599,8 +2604,12 @@ public function upsertDocuments(
             $spatialAttributes = $this->getSpatialAttributes($collection);
 
             $attributeDefaults = [];
+            $arrayAttributes = [];
             foreach ($collection->getAttribute('attributes', []) as $attr) {
                 $attributeDefaults[$attr['$id']] = $attr['default'] ?? null;
+                if ($attr['array'] ?? false) {
+                    $arrayAttributes[$attr['$id']] = true;
+                }
             }
 
             $collection = $collection->getId();
@@ -2671,6 +2680,11 @@ public function upsertDocuments(
                     foreach ($allColumnNames as $attributeKey) {
                         $attrValue = $currentRegularAttributes[$attributeKey] ?? null;
 
+                        // Array columns are NOT NULL DEFAULT '[]', so coerce null to empty array
+                        if ($attrValue === null && isset($arrayAttributes[$attributeKey])) {
+                            $attrValue = '[]';
+                        }
+
                         if (\is_array($attrValue)) {
                             $attrValue = \json_encode($attrValue);
                         }
@@ -2798,6 +2812,11 @@ public function upsertDocuments(
                         foreach ($allColumnNames as $attributeKey) {
                             $attrValue = $currentRegularAttributes[$attributeKey] ?? null;
 
+                            // Array columns are NOT NULL DEFAULT '[]', so coerce null to empty array
+                            if ($attrValue === null && isset($arrayAttributes[$attributeKey])) {
+                                $attrValue = '[]';
+                            }
+
                             if (\is_array($attrValue)) {
                                 $attrValue = \json_encode($attrValue);
                             }
diff --git a/src/Database/Database.php b/src/Database/Database.php
index c9e3f263f..f4daec5cf 100644
--- a/src/Database/Database.php
+++ b/src/Database/Database.php
@@ -8200,6 +8200,13 @@ public function encode(Document $collection, Document $document, bool $applyDefa
 
             // Continue on optional param with no default
             if (is_null($value) && is_null($default)) {
+                // Non-required array columns are NOT NULL with DEFAULT '[]', so coerce null to empty array.
+                // Required arrays must remain null so the Structure validator catches the missing value.
+                // Only coerce when applying defaults (inserts) to avoid clearing existing values during partial updates.
+                $required = $attribute['required'] ?? false;
+                if ($applyDefaults && $array && !$required) {
+                    $document->setAttribute($key, []);
+                }
                 continue;
             }
 
diff --git a/tests/e2e/Adapter/Base.php b/tests/e2e/Adapter/Base.php
index 4baeba35b..250bf5171 100644
--- a/tests/e2e/Adapter/Base.php
+++ b/tests/e2e/Adapter/Base.php
@@ -49,6 +49,11 @@ abstract class Base extends TestCase
      */
     abstract protected function getDatabase(): Database;
 
+    /**
+     * @return \Utopia\Database\PDO|\PDO|null
+     */
+    abstract protected function getPDO(): mixed;
+
     /**
      * @param string $collection
      * @param string $column
diff --git a/tests/e2e/Adapter/MariaDBTest.php b/tests/e2e/Adapter/MariaDBTest.php
index 923de242e..726c432d8 100644
--- a/tests/e2e/Adapter/MariaDBTest.php
+++ b/tests/e2e/Adapter/MariaDBTest.php
@@ -52,6 +52,11 @@ public function getDatabase(bool $fresh = false): Database
         return self::$database = $database;
     }
 
+    protected function getPDO(): mixed
+    {
+        return self::$pdo;
+    }
+
     protected function deleteColumn(string $collection, string $column): bool
     {
         $sqlTable = "`" . $this->getDatabase()->getDatabase() . "`.`" . $this->getDatabase()->getNamespace() . "_" . $collection . "`";
diff --git a/tests/e2e/Adapter/MirrorTest.php b/tests/e2e/Adapter/MirrorTest.php
index 31bf3f3b6..97fbe143c 100644
--- a/tests/e2e/Adapter/MirrorTest.php
+++ b/tests/e2e/Adapter/MirrorTest.php
@@ -313,6 +313,11 @@ public function testDeleteMirroredDocument(): void
         $this->assertTrue($database->getDestination()->getDocument('testDeleteMirroredDocument', $document->getId())->isEmpty());
     }
 
+    protected function getPDO(): mixed
+    {
+        return self::$sourcePdo;
+    }
+
     protected function deleteColumn(string $collection, string $column): bool
     {
         $sqlTable = "`" . self::$source->getDatabase() . "`.`" . self::$source->getNamespace() . "_" . $collection . "`";
diff --git a/tests/e2e/Adapter/MongoDBTest.php b/tests/e2e/Adapter/MongoDBTest.php
index 1c7eb9237..4fc21ad63 100644
--- a/tests/e2e/Adapter/MongoDBTest.php
+++ b/tests/e2e/Adapter/MongoDBTest.php
@@ -98,6 +98,11 @@ public function testKeywords(): void
         $this->assertTrue(true);
     }
 
+    protected function getPDO(): mixed
+    {
+        return null;
+    }
+
     protected function deleteColumn(string $collection, string $column): bool
     {
         return true;
diff --git a/tests/e2e/Adapter/MySQLTest.php b/tests/e2e/Adapter/MySQLTest.php
index 8e92bb216..d0e5218b3 100644
--- a/tests/e2e/Adapter/MySQLTest.php
+++ b/tests/e2e/Adapter/MySQLTest.php
@@ -58,6 +58,11 @@ public function getDatabase(): Database
         return self::$database = $database;
     }
 
+    protected function getPDO(): mixed
+    {
+        return self::$pdo;
+    }
+
     protected function deleteColumn(string $collection, string $column): bool
     {
         $sqlTable = "`" . $this->getDatabase()->getDatabase() . "`.`" . $this->getDatabase()->getNamespace() . "_" . $collection . "`";
diff --git a/tests/e2e/Adapter/PoolTest.php b/tests/e2e/Adapter/PoolTest.php
index 94c2d4147..eee758e6d 100644
--- a/tests/e2e/Adapter/PoolTest.php
+++ b/tests/e2e/Adapter/PoolTest.php
@@ -79,6 +79,18 @@ public function getDatabase(): Database
         return self::$database = $database;
     }
 
+    protected function getPDO(): mixed
+    {
+        $pdo = null;
+        self::$pool->use(function (Adapter $adapter) use (&$pdo) {
+            $class = new ReflectionClass($adapter);
+            $property = $class->getProperty('pdo');
+            $property->setAccessible(true);
+            $pdo = $property->getValue($adapter);
+        });
+        return $pdo;
+    }
+
     protected function deleteColumn(string $collection, string $column): bool
     {
         $sqlTable = "`" . $this->getDatabase()->getDatabase() . "`.`" . $this->getDatabase()->getNamespace() . "_" . $collection . "`";
diff --git a/tests/e2e/Adapter/PostgresTest.php b/tests/e2e/Adapter/PostgresTest.php
index 58beaf64e..6db6ead1d 100644
--- a/tests/e2e/Adapter/PostgresTest.php
+++ b/tests/e2e/Adapter/PostgresTest.php
@@ -51,6 +51,11 @@ public function getDatabase(): Database
         return self::$database = $database;
     }
 
+    protected function getPDO(): mixed
+    {
+        return self::$pdo;
+    }
+
     protected function deleteColumn(string $collection, string $column): bool
     {
         $sqlTable = '"' . $this->getDatabase()->getDatabase(). '"."' . $this->getDatabase()->getNamespace() . '_' . $collection . '"';
diff --git a/tests/e2e/Adapter/SQLiteTest.php b/tests/e2e/Adapter/SQLiteTest.php
index 6061352e4..443067e66 100644
--- a/tests/e2e/Adapter/SQLiteTest.php
+++ b/tests/e2e/Adapter/SQLiteTest.php
@@ -55,6 +55,11 @@ public function getDatabase(): Database
         return self::$database = $database;
     }
 
+    protected function getPDO(): mixed
+    {
+        return self::$pdo;
+    }
+
     protected function deleteColumn(string $collection, string $column): bool
     {
         $sqlTable = "`" . $this->getDatabase()->getNamespace() . "_" . $collection . "`";
diff --git a/tests/e2e/Adapter/Scopes/AttributeTests.php b/tests/e2e/Adapter/Scopes/AttributeTests.php
index bf376d101..779c3f5c7 100644
--- a/tests/e2e/Adapter/Scopes/AttributeTests.php
+++ b/tests/e2e/Adapter/Scopes/AttributeTests.php
@@ -1620,10 +1620,11 @@ public function testArrayAttribute(): void
                 $this->assertEquals('Invalid query: Cannot query contains on attribute "age" because it is not an array, string, or object.', $e->getMessage());
             }
 
+            // Array columns are NOT NULL with DEFAULT empty array, so isNull returns nothing
             $documents = $database->find($collection, [
                 Query::isNull('long_size')
             ]);
-            $this->assertCount(1, $documents);
+            $this->assertCount(0, $documents);
 
             $documents = $database->find($collection, [
                 Query::contains('tv_show', ['love'])
diff --git a/tests/e2e/Adapter/Scopes/CollectionTests.php b/tests/e2e/Adapter/Scopes/CollectionTests.php
index ccf884f5c..adb885ddd 100644
--- a/tests/e2e/Adapter/Scopes/CollectionTests.php
+++ b/tests/e2e/Adapter/Scopes/CollectionTests.php
@@ -569,10 +569,10 @@ public function testSchemaAttributes(): void
 
         $attribute = $attributes['string_list'];
         $this->assertEquals('string_list', $attribute['$id']);
-        $this->assertTrue(in_array($attribute['dataType'], ['json', 'longtext'])); // mysql vs maria
-        $this->assertTrue(in_array($attribute['columnType'], ['json', 'longtext']));
+        $this->assertTrue(in_array($attribute['dataType'], ['json', 'jsonb', 'longtext']));
+        $this->assertTrue(in_array($attribute['columnType'], ['json', 'jsonb', 'longtext']));
         $this->assertTrue(in_array($attribute['characterMaximumLength'], [null, '4294967295']));
-        $this->assertEquals('YES', $attribute['isNullable']);
+        $this->assertEquals('NO', $attribute['isNullable']);
 
         $attribute = $attributes['dob'];
         $this->assertEquals('dob', $attribute['$id']);
diff --git a/tests/e2e/Adapter/Scopes/DocumentTests.php b/tests/e2e/Adapter/Scopes/DocumentTests.php
index d1241ad26..dc8caad12 100644
--- a/tests/e2e/Adapter/Scopes/DocumentTests.php
+++ b/tests/e2e/Adapter/Scopes/DocumentTests.php
@@ -4403,6 +4403,63 @@ public function testEncodeDecode(): void
             new Document(['$id' => '3', 'label' => 'z']),
         ], $result->getAttribute('tags'));
     }
+
+    /**
+     * Regression: encode() with applyDefaults:false must not coerce
+     * unspecified optional array attributes to [], which would clear
+     * their stored values during partial updates.
+     */
+    public function testEncodePartialUpdatePreservesArrayAttributes(): void
+    {
+        $collection = new Document([
+            '$collection' => ID::custom(Database::METADATA),
+            '$id' => ID::custom('items'),
+            'name' => 'Items',
+            'attributes' => [
+                [
+                    '$id' => ID::custom('title'),
+                    'type' => Database::VAR_STRING,
+                    'format' => '',
+                    'size' => 256,
+                    'signed' => true,
+                    'required' => false,
+                    'default' => null,
+                    'array' => false,
+                    'filters' => [],
+                ],
+                [
+                    '$id' => ID::custom('tags'),
+                    'type' => Database::VAR_STRING,
+                    'format' => '',
+                    'size' => 255,
+                    'signed' => true,
+                    'required' => false,
+                    'default' => null,
+                    'array' => true,
+                    'filters' => [],
+                ],
+            ],
+            'indexes' => [],
+        ]);
+
+        // Partial update: only 'title' is provided, 'tags' is absent
+        $partialUpdate = new Document([
+            '$id' => ID::custom('doc1'),
+            'title' => 'Updated Title',
+        ]);
+
+        /** @var Database $database */
+        $database = $this->getDatabase();
+
+        $result = $database->encode($collection, $partialUpdate, applyDefaults: false);
+
+        $this->assertEquals('Updated Title', $result->getAttribute('title'));
+        $this->assertNull(
+            $result->getAttribute('tags'),
+            'Unspecified optional array attribute must remain null during partial update, not be coerced to []'
+        );
+    }
+
     /**
      * @depends testGetDocument
      */
diff --git a/tests/e2e/Adapter/Scopes/IndexTests.php b/tests/e2e/Adapter/Scopes/IndexTests.php
index 3f5c101f6..f880ac12b 100644
--- a/tests/e2e/Adapter/Scopes/IndexTests.php
+++ b/tests/e2e/Adapter/Scopes/IndexTests.php
@@ -1048,4 +1048,161 @@ public function testTTLIndexDuplicatePrevention(): void
         // Cleanup
         $database->deleteCollection($col);
     }
+
+    /**
+     * Verifies that array attributes backed by JSON columns are created as
+     * NOT NULL DEFAULT (empty array). This is required because:
+     *
+     * 1. MySQL bug #111037: the optimizer can skip functional indexes
+     *    (CAST ... AS ARRAY) on nullable columns in complex query plans.
+     * 2. Correctness: JSON_CONTAINS(NULL, ...) returns NULL, not FALSE,
+     *    so rows with NULL array columns are invisible to both positive
+     *    and negative array queries (containsAny / notContains).
+     *
+     * @link https://bugs.mysql.com/bug.php?id=111037
+     */
+    public function testArrayAttributeNotNullSchema(): void
+    {
+        $database = $this->getDatabase();
+        $adapter = $database->getAdapter();
+
+        if (!$adapter->getSupportForSchemaAttributes()) {
+            $this->expectNotToPerformAssertions();
+            return;
+        }
+
+        $collection = 'arrayNotNull';
+
+        $database->createCollection($collection, permissions: [
+            Permission::create(Role::any()),
+            Permission::read(Role::any()),
+        ]);
+
+        $database->createAttribute($collection, 'tags', Database::VAR_STRING, 255, false, array: true);
+
+        // Verify the physical column is NOT NULL via INFORMATION_SCHEMA
+        $pdo = $this->getPDO();
+
+        $ns = $database->getNamespace();
+        $db = $database->getDatabase();
+        $tableName = "{$ns}_{$collection}";
+
+        $stmt = $pdo->prepare(
+            'SELECT IS_NULLABLE, COLUMN_DEFAULT '
+            . 'FROM INFORMATION_SCHEMA.COLUMNS '
+            . 'WHERE TABLE_SCHEMA = ? AND TABLE_NAME = ? AND COLUMN_NAME = ?'
+        );
+        $stmt->execute([$db, $tableName, 'tags']);
+        $col = $stmt->fetch(\PDO::FETCH_ASSOC);
+        // PostgreSQL returns lowercase keys from INFORMATION_SCHEMA
+        $col = $col ? \array_change_key_case($col, CASE_UPPER) : false;
+
+        $this->assertNotFalse($col, 'Column "tags" should exist in INFORMATION_SCHEMA');
+        $this->assertEquals(
+            'NO',
+            $col['IS_NULLABLE'],
+            'Array (JSON) column must be NOT NULL so the optimizer can use multi-valued indexes '
+            . 'and JSON_CONTAINS/JSON_OVERLAPS never encounter NULL'
+        );
+
+        $database->deleteCollection($collection);
+    }
+
+    /**
+     * Verifies that the index on an array attribute is picked by the
+     * optimizer and that queries return correct results.
+     */
+    public function testArrayIndexUsedInQuery(): void
+    {
+        $database = $this->getDatabase();
+        $adapter = $database->getAdapter();
+
+        if (!$adapter->getSupportForCastIndexArray()) {
+            $this->expectNotToPerformAssertions();
+            return;
+        }
+
+        $collection = 'arrayIndexExplain';
+
+        $database->createCollection($collection, permissions: [
+            Permission::create(Role::any()),
+            Permission::read(Role::any()),
+        ]);
+
+        $database->createAttribute($collection, 'tags', Database::VAR_STRING, 255, false, array: true);
+        $database->createIndex($collection, 'idx_tags', Database::INDEX_KEY, ['tags'], [255]);
+
+        // PostgreSQL's planner needs a larger dataset to choose a GIN index over a sequential scan.
+        $total = $adapter->getSupportForGinIndex() ? 5000 : 500;
+        $documents = [];
+        for ($i = 0; $i < $total; $i++) {
+            $documents[] = new Document([
+                '$id' => ID::unique(),
+                '$permissions' => [Permission::read(Role::any())],
+                'tags' => ['tag_' . ($i % 50), 'common'],
+            ]);
+        }
+
+        foreach (\array_chunk($documents, 100) as $chunk) {
+            $database->createDocuments($collection, $chunk);
+        }
+
+        $pdo = $this->getPDO();
+        $ns = $database->getNamespace();
+        $db = $database->getDatabase();
+
+        if ($adapter->getSupportForGinIndex()) {
+            $table = "\"{$db}\".\"{$ns}_{$collection}\"";
+
+            // Verify GIN index exists
+            $stmt = $pdo->prepare(
+                "SELECT indexdef FROM pg_indexes WHERE tablename = ? AND indexname LIKE ?"
+            );
+            $stmt->execute(["{$ns}_{$collection}", '%idx_tags%']);
+            $indexDef = $stmt->fetchColumn();
+            $this->assertNotFalse($indexDef, 'GIN index should exist for array column');
+            $this->assertStringContainsString('gin', \strtolower($indexDef), 'Index on array column should be a GIN index');
+
+            // Update planner statistics and verify the GIN index is chosen
+            $pdo->prepare("ANALYZE {$table}")->execute();
+            $stmt = $pdo->prepare("EXPLAIN SELECT * FROM {$table} WHERE \"tags\" @> '[\"tag_1\"]'::jsonb");
+            $stmt->execute();
+            $plan = \implode("\n", $stmt->fetchAll(\PDO::FETCH_COLUMN));
+            $this->assertMatchesRegularExpression(
+                '/Bitmap Heap Scan|Index Scan/i',
+                $plan,
+                "PostgreSQL should use the GIN index for @> containment query. EXPLAIN output:\n" . $plan
+            );
+        } else {
+            $table = "`{$db}`.`{$ns}_{$collection}`";
+
+            $pdo->prepare("ANALYZE TABLE {$table}")->execute();
+
+            $sql = "EXPLAIN SELECT * FROM {$table} WHERE JSON_CONTAINS(`tags`, '[\"tag_1\"]')";
+            $stmt = $pdo->prepare($sql);
+            $stmt->execute();
+            $explain = $stmt->fetchAll();
+
+            $usedKey = $explain[0]['key'] ?? null;
+            $this->assertNotNull(
+                $usedKey,
+                'MySQL should use an index for JSON_CONTAINS on a NOT NULL JSON column. '
+                . "EXPLAIN output:\n" . \print_r($explain, true)
+            );
+            $this->assertStringContainsString(
+                'idx_tags',
+                $usedKey,
+                "Expected the 'idx_tags' index to be used. EXPLAIN output:\n" . \print_r($explain, true)
+            );
+        }
+
+        // Verify the query also returns correct functional results
+        $expectedCount = $total / 50; // each tag_N appears once per 50 documents
+        $results = $database->find($collection, [
+            Query::containsAny('tags', ['tag_1']),
+        ]);
+        $this->assertCount($expectedCount, $results);
+
+        $database->deleteCollection($collection);
+    }
 }
diff --git a/tests/e2e/Adapter/Scopes/RelationshipTests.php b/tests/e2e/Adapter/Scopes/RelationshipTests.php
index 9182b8b8b..5ada5b10b 100644
--- a/tests/e2e/Adapter/Scopes/RelationshipTests.php
+++ b/tests/e2e/Adapter/Scopes/RelationshipTests.php
@@ -157,7 +157,7 @@ public function testZoo(): void
             'price' => 1000,
             'dateOfBirth' => '1975-06-12',
             'isActive' => true,
-            'integers' => null,
+            'integers' => [],
             'email' => null,
             'enum' => null,
             'ip' => '255.0.0.1',
diff --git a/tests/e2e/Adapter/SharedTables/MariaDBTest.php b/tests/e2e/Adapter/SharedTables/MariaDBTest.php
index f6574ab0d..54b195892 100644
--- a/tests/e2e/Adapter/SharedTables/MariaDBTest.php
+++ b/tests/e2e/Adapter/SharedTables/MariaDBTest.php
@@ -67,6 +67,11 @@ public function getDatabase(bool $fresh = false): Database
         return self::$database = $database;
     }
 
+    protected function getPDO(): mixed
+    {
+        return self::$pdo;
+    }
+
     protected function deleteColumn(string $collection, string $column): bool
     {
         $sqlTable = "`" . $this->getDatabase()->getDatabase() . "`.`" . $this->getDatabase()->getNamespace() . "_" . $collection . "`";
diff --git a/tests/e2e/Adapter/SharedTables/MongoDBTest.php b/tests/e2e/Adapter/SharedTables/MongoDBTest.php
index 61904861c..3185c22b0 100644
--- a/tests/e2e/Adapter/SharedTables/MongoDBTest.php
+++ b/tests/e2e/Adapter/SharedTables/MongoDBTest.php
@@ -100,6 +100,11 @@ public function testKeywords(): void
         $this->assertTrue(true);
     }
 
+    protected function getPDO(): mixed
+    {
+        return null;
+    }
+
     protected function deleteColumn(string $collection, string $column): bool
     {
         return true;
diff --git a/tests/e2e/Adapter/SharedTables/MySQLTest.php b/tests/e2e/Adapter/SharedTables/MySQLTest.php
index 697c42c7e..dc78f7b56 100644
--- a/tests/e2e/Adapter/SharedTables/MySQLTest.php
+++ b/tests/e2e/Adapter/SharedTables/MySQLTest.php
@@ -69,6 +69,11 @@ public function getDatabase(): Database
         return self::$database = $database;
     }
 
+    protected function getPDO(): mixed
+    {
+        return self::$pdo;
+    }
+
     protected function deleteColumn(string $collection, string $column): bool
     {
         $sqlTable = "`" . $this->getDatabase()->getDatabase() . "`.`" . $this->getDatabase()->getNamespace() . "_" . $collection . "`";
diff --git a/tests/e2e/Adapter/SharedTables/PostgresTest.php b/tests/e2e/Adapter/SharedTables/PostgresTest.php
index cb9633c01..2d01a621c 100644
--- a/tests/e2e/Adapter/SharedTables/PostgresTest.php
+++ b/tests/e2e/Adapter/SharedTables/PostgresTest.php
@@ -64,6 +64,11 @@ public function getDatabase(): Database
         return self::$database = $database;
     }
 
+    protected function getPDO(): mixed
+    {
+        return self::$pdo;
+    }
+
     protected function deleteColumn(string $collection, string $column): bool
     {
         $sqlTable = '"' . $this->getDatabase()->getDatabase() . '"."' . $this->getDatabase()->getNamespace() . '_' . $collection . '"';
diff --git a/tests/e2e/Adapter/SharedTables/SQLiteTest.php b/tests/e2e/Adapter/SharedTables/SQLiteTest.php
index ea4a042ea..029de2053 100644
--- a/tests/e2e/Adapter/SharedTables/SQLiteTest.php
+++ b/tests/e2e/Adapter/SharedTables/SQLiteTest.php
@@ -70,6 +70,11 @@ public function getDatabase(): Database
         return self::$database = $database;
     }
 
+    protected function getPDO(): mixed
+    {
+        return self::$pdo;
+    }
+
     protected function deleteColumn(string $collection, string $column): bool
     {
         $sqlTable = "`" . $this->getDatabase()->getNamespace() . "_" . $collection . "`";