reverted:
--- b/core/lib/Drupal/Core/Database/Driver/pgsql/Connection.php
+++ a/core/lib/Drupal/Core/Database/Driver/pgsql/Connection.php
@@ -9,7 +9,7 @@
 use Drupal\Core\Database\StatementInterface;
 use Drupal\Core\Database\StatementWrapper;
 
+// cSpell:ignore ilike nextval
-// cSpell:ignore ilike nextval relname relkind relname
 
 /**
  * @addtogroup database
@@ -368,45 +368,6 @@
     }
   }
 
-  /**
-   * Retrieves a sequence name that is owned by the table and column..
-   *
-   * @param string $table
-   *   A table name that is not prefixed or quoted.
-   * @param string $column
-   *   The column name.
-   *
-   * @return string|null
-   *   The name of the sequence or NULL if it does not exist.
-   */
-  public function getSequence($table, $column) {
-    $args = [
-      ':table' => $this->prefixTables('{' . $table . '}'),
-      ':column' => $column,
-    ];
-    return $this
-      ->query("SELECT pg_get_serial_sequence(:table, :column)", $args)
-      ->fetchField();
-  }
-
-  /**
-   * Checks if a sequence exists.
-   *
-   * @param string $name
-   *   The fully-qualified sequence name.
-   *
-   * @return bool
-   *   TRUE if the sequence exists by the name.
-   *
-   * @see \Drupal\Core\Database\Connection::makeSequenceName()
-   */
-  public function sequenceExists($name) {
-    $args = [':name' => $name];
-    return (bool) $this
-      ->query("SELECT c.relname FROM pg_class as c WHERE c.relkind = 'S' AND c.relname = :name", $args)
-      ->fetchField();
-  }
-
 }
 
 /**
reverted:
--- b/core/lib/Drupal/Core/Database/Driver/pgsql/Schema.php
+++ a/core/lib/Drupal/Core/Database/Driver/pgsql/Schema.php
@@ -971,7 +971,7 @@
       // not when altering. Because of that, the sequence needs to be created
       // and initialized by hand.
       $seq = $this->connection->makeSequenceName($table, $field_new);
+      $this->connection->query("CREATE SEQUENCE " . $seq);
-      $this->connection->query("CREATE SEQUENCE " . $seq . " OWNED BY {" . $table . "}." . $field_new);
       // Set sequence to maximal field value to not conflict with existing
       // entries.
       $this->connection->query("SELECT setval('" . $seq . "', MAX(\"" . $field . '")) FROM {' . $table . "}");
@@ -1029,25 +1029,6 @@
     }
   }
 
-  /**
-   * Alters the ownership of a sequence.
-   *
-   * This is used for updating orphaned sequences.
-   * See issue https://www.drupal.org/project/drupal/issues/3028706
-   *
-   * @param string $table
-   *   The unquoted or prefixed table name.
-   * @param string $column
-   *   The column name for the sequence.
-   *
-   * @internal
-   */
-  public function updateSequenceOwnership($table, $column) {
-    $seq = $this->connection->makeSequenceName($table, $column);
-    $table_name = $this->connection->prefixTables('{' . $table . '}');
-    $this->connection->query('ALTER SEQUENCE IF EXISTS ' . $seq . ' OWNED BY ' . $table_name . '.' . $column);
-  }
-
   /**
    * Retrieve a table or column comment.
    */
diff -u b/core/modules/system/system.install b/core/modules/system/system.install
--- b/core/modules/system/system.install
+++ b/core/modules/system/system.install
@@ -1656,7 +1656,7 @@
 /**
  * Fix any orphan sequences created from column changes in PostgreSQL.
  */
-function system_update_9101(&$sandbox) {
+function system_update_9401(&$sandbox) {
   $connection = \Drupal::database();
   if ($connection->databaseType() !== 'pgsql') {
     // This database update is a no-op for all other core database drivers.
@@ -1734,12 +1734,13 @@
     // sequence exists at all before trying to alter it.
     foreach ($to_process as $table_info) {
       if ($connection->schema()->tableExists($table_info['table'])) {
-        $owned = (bool) $connection->getSequence($table_info['table'], $table_info['column']);
+        $owned = (bool) $connection->schema()->getSequenceName($table_info['table'], $table_info['column']);
 
         if (!$owned) {
           $sequence_name = $connection
             ->makeSequenceName($table_info['table'], $table_info['column']);
           $exists = $connection
+            ->schema()
             ->sequenceExists($sequence_name);
           if ($exists) {
             $transaction = $connection->startTransaction($sequence_name);
diff -u b/core/modules/system/tests/src/Functional/Database/PostgreSqlSequenceUpdateTest.php b/core/modules/system/tests/src/Functional/Database/PostgreSqlSequenceUpdateTest.php
--- b/core/modules/system/tests/src/Functional/Database/PostgreSqlSequenceUpdateTest.php
+++ b/core/modules/system/tests/src/Functional/Database/PostgreSqlSequenceUpdateTest.php
@@ -3,6 +3,7 @@
 namespace Drupal\Tests\system\Functional\Database;
 
 use Drupal\FunctionalTests\Update\UpdatePathTestBase;
+use Drupal\Core\Database\Database;
 
 /**
  * Tests that any unowned sequences created previously have a table owner.
@@ -34,10 +35,13 @@
     $this->runUpdates();
 
     if ($db_type === 'pgsql') {
-      $sequence_exists = (bool) $database
-        ->query("SELECT pg_get_serial_sequence('{" . $database->prefixTables('pgsql_sequence_test') . "}', 'sequence_field')")
-        ->fetchField();
-      $this->assertTrue($sequence_exists, 'Sequence is owned by the table and column.');
+      $connection = Database::getConnection();
+      $schema = $connection->schema();
+      $seq_owner = $schema->getSequenceOwner();
+      if ($seq_owner) {
+        $this->assertEquals($connection->tablePrefix('users') . 'users', $seq_owner->table_name);
+        $this->assertEquals('uid', $seq_owner->field_name, 'Sequence is owned by the table and column.');
+      }
     }
     else {
       $this->assertTrue(TRUE, 'Database update ran successfully on non-pgsql driver.');
diff -u b/core/tests/Drupal/KernelTests/Core/Database/SchemaTest.php b/core/tests/Drupal/KernelTests/Core/Database/SchemaTest.php
--- b/core/tests/Drupal/KernelTests/Core/Database/SchemaTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Database/SchemaTest.php
@@ -166,10 +166,11 @@
     $this->schema->changeField('test_table', 'test_serial', 'test_serial', ['type' => 'serial', 'not null' => TRUE, 'description' => 'Changed column description.'], ['primary key' => ['test_serial']]);
     // Confirms that the new sequence is owned by the table in PostgreSQL.
     if ($db_type == 'pgsql') {
-      $sequence_exists = (bool) $this->connection
-        ->query("SELECT pg_get_serial_sequence('{test_table}', 'test_serial')")
-        ->fetchField();
-      $this->assertTrue($sequence_exists, 'New sequence is owned by its table.');
+      $seq_owner = $this->schema->getSequenceOwner();
+      if ($seq_owner) {
+        $this->assertEquals($this->connection->tablePrefix('users') . 'users', $seq_owner->table_name);
+        $this->assertEquals('uid', $seq_owner->field_name, 'New sequence is owned by its table.');
+      }
     }
 
     // Assert that the column comment has been set.
only in patch2:
unchanged:
--- a/core/modules/pgsql/src/Driver/Database/pgsql/Connection.php
+++ b/core/modules/pgsql/src/Driver/Database/pgsql/Connection.php
@@ -9,7 +9,7 @@
 use Drupal\Core\Database\StatementInterface;
 use Drupal\Core\Database\StatementWrapper;
 
-// cSpell:ignore ilike nextval
+// cSpell:ignore ilike nextval relname relkind relname.
 
 /**
  * @addtogroup database
only in patch2:
unchanged:
--- a/core/modules/pgsql/src/Driver/Database/pgsql/Schema.php
+++ b/core/modules/pgsql/src/Driver/Database/pgsql/Schema.php
@@ -971,7 +971,7 @@ public function changeField($table, $field, $field_new, $spec, $new_keys = []) {
       // not when altering. Because of that, the sequence needs to be created
       // and initialized by hand.
       $seq = $this->connection->makeSequenceName($table, $field_new);
-      $this->connection->query("CREATE SEQUENCE " . $seq);
+      $this->connection->query("CREATE SEQUENCE " . $seq . " OWNED BY {" . $table . "}." . $field_new);
       // Set sequence to maximal field value to not conflict with existing
       // entries.
       $this->connection->query("SELECT setval('" . $seq . "', MAX(\"" . $field . '")) FROM {' . $table . "}");
@@ -1077,6 +1077,82 @@ public function extensionExists($name): bool {
     ])->fetchField();
   }
 
+  /**
+   * Alters the ownership of a sequence.
+   *
+   * This is used for updating orphaned sequences.
+   * See issue https://www.drupal.org/project/drupal/issues/3028706
+   *
+   * @param string $table
+   *   The unquoted or prefixed table name.
+   * @param string $column
+   *   The column name for the sequence.
+   *
+   * @internal
+   */
+  public function updateSequenceOwnership(string $table, string $column) {
+    $seq = $this->connection->makeSequenceName($table, $column);
+    $table_name = $this->connection->prefixTables('{' . $table . '}');
+    $this->connection->query('ALTER SEQUENCE IF EXISTS ' . $seq . ' OWNED BY ' . $table_name . '.' . $column);
+  }
+
+  /**
+   * Retrieves a sequence name that is owned by the table and column..
+   *
+   * @param string $table
+   *   A table name that is not prefixed or quoted.
+   * @param string $column
+   *   The column name.
+   *
+   * @return string|null
+   *   The name of the sequence or NULL if it does not exist.
+   */
+  public function getSequenceName(string $table, string $column): ?string {
+    $args = [
+      ':table' => $this->prefixTables('{' . $table . '}'),
+      ':column' => $column,
+    ];
+    return $this
+      ->query("SELECT pg_get_serial_sequence(:table, :column)", $args)
+      ->fetchField();
+  }
+
+  /**
+   * Checks if a sequence exists.
+   *
+   * @param string $name
+   *   The fully-qualified sequence name.
+   *
+   * @return bool
+   *   TRUE if the sequence exists by the name.
+   *
+   * @see \Drupal\Core\Database\Connection::makeSequenceName()
+   */
+  public function sequenceExists(string $name): bool {
+    $args = [':name' => $name];
+    return (bool) $this
+      ->query("SELECT c.relname FROM pg_class as c WHERE c.relkind = 'S' AND c.relname = :name", $args)
+      ->fetchField();
+  }
+
+  /**
+   * Retrives the sequence owner object.
+   *
+   * @return array|null
+   *   Returns the sequence owner object or NULL if it does not exist..
+   */
+  public function getSequenceOwner(): ?array {
+    $seq_name = $connection->makeSequenceName('users', 'uid');
+    $seq_owner = $connection->query("SELECT d.refobjid::regclass as table_name, a.attname as field_name
+      FROM pg_depend d
+      JOIN pg_attribute a ON a.attrelid = d.refobjid AND a.attnum = d.refobjsubid
+      WHERE d.objid = :seq_name::regclass
+      AND d.refobjsubid > 0
+      AND d.classid = 'pg_class'::regclass", [':seq_name' => 'public.' . $seq_name])->fetchObject();
+    return $seq_owner;
+
+  }
+
 }
 
 /**