From d62807e9edc553b1eb08c10ce28521a71007a263 Mon Sep 17 00:00:00 2001
From: Diego Imbert <diego@windmill.dev>
Date: Thu, 17 Sep 2026 18:04:19 +0200
Subject: [PATCH] fix(datatables): stop counting storage-only fork cleanup rows
 as uses of an external database

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
---
 backend/windmill-common/src/external_instance_pg.rs | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/backend/windmill-common/src/external_instance_pg.rs b/backend/windmill-common/src/external_instance_pg.rs
index cb2825349d..75623e867e 100644
--- a/backend/windmill-common/src/external_instance_pg.rs
+++ b/backend/windmill-common/src/external_instance_pg.rs
@@ -130,8 +130,9 @@ pub async fn external_instance_databases(db: &DB) -> Result<BTreeMap<String, Cus
 }
 
 /// The workspaces whose data tables or Ducklake catalogs name each database on the external cluster,
-/// and the forks whose Ducklake namespaces there are still waiting to be cleaned up: those rows
-/// outlive a settings change, and cleanup cannot drop a namespace in a database that is gone.
+/// and the forks whose Ducklake metadata schemas there are still waiting to be dropped: those rows
+/// outlive a settings change, and cleanup cannot drop a schema in a database that is gone. A row
+/// whose schema is already dropped only waits on object storage, which needs no database.
 ///
 /// Authorization: reads every workspace's settings and checks nothing. Callers MUST be superadmin
 /// or an internal lifecycle path.
@@ -161,7 +162,7 @@ pub async fn external_instance_database_usages<'c>(
          UNION ALL
          SELECT workspace_id, substring(catalog FROM length('external_instance:') + 1)
          FROM fork_ducklake_namespace
-         WHERE catalog LIKE 'external\\_instance:%'",
+         WHERE catalog LIKE 'external\\_instance:%' AND NOT schema_dropped",
     )
     .fetch_all(db)
     .await?;