add migration (#4932)

Author: RobertJoonas

priv/ingest_repo/migrations/20241231083407_add_pageleave_visitors_to_imported_pages.exs

@@ -0,0 +1,21 @@
+defmodule Plausible.IngestRepo.Migrations.AddPageleaveVisitorsToImportedPages do
+  use Ecto.Migration
+
+  @on_cluster Plausible.MigrationUtils.on_cluster_statement("imported_pages")
+
+  def up do
+    execute """
+    ALTER TABLE imported_pages
+    #{@on_cluster}
+    ADD COLUMN pageleave_visitors UInt64
+    """
+  end
+
+  def down do
+    execute """
+    ALTER TABLE imported_pages
+    #{@on_cluster}
+    DROP COLUMN pageleave_visitors
+    """
+  end
+end