diff --git a/apps/backend/src/lib/external-db-sync.ts b/apps/backend/src/lib/external-db-sync.ts
index 885952530..d2f25202b 100644
--- a/apps/backend/src/lib/external-db-sync.ts
+++ b/apps/backend/src/lib/external-db-sync.ts
@@ -1433,7 +1433,9 @@ async function syncClickhouseMapping(
   }
 
   const clickhouseTableName = `analytics_internal.${mapping.targetTable}`;
-  await ensureClickhouseSchema(client, tableSchema, clickhouseTableName);
+  // Skip ensureClickhouseSchema — we only sync to our own internal ClickHouse
+  // where tables are already created. CREATE TABLE IF NOT EXISTS is always a
+  // no-op but costs a slow DDL round trip per mapping per sync invocation.
 
   let lastSequenceId = await getClickhouseLastSyncedSequenceId(client, tenancyId, mappingId);