diff --git a/src/api/tables.ts b/src/api/tables.ts
index 668ea359..f2f9af51 100644
--- a/src/api/tables.ts
+++ b/src/api/tables.ts
@@ -122,12 +122,12 @@ router.delete('/:id', async (req, res) => {
 const getTablesSql = (sqlTemplates) => {
   const { columns, grants, policies, primary_keys, relationships, tables } = sqlTemplates
   return `
-  WITH tables AS ( ${tables} ),
-    columns AS ( ${columns} ),
-    grants AS ( ${grants} ),
-    policies AS ( ${policies} ),
-    primary_keys AS ( ${primary_keys} ),
-    relationships AS ( ${relationships} )
+  WITH tables AS MATERIALIZED ( ${tables} ),
+    columns AS MATERIALIZED ( ${columns} ),
+    grants AS MATERIALIZED ( ${grants} ),
+    policies AS MATERIALIZED ( ${policies} ),
+    primary_keys AS MATERIALIZED ( ${primary_keys} ),
+    relationships AS MATERIALIZED ( ${relationships} )
   SELECT
     *,
     ${coalesceRowsToArray('columns', 'SELECT * FROM columns WHERE columns.table_id = tables.id')},
diff --git a/src/lib/helpers.ts b/src/lib/helpers.ts
index e1bf75b7..69e7a96b 100644
--- a/src/lib/helpers.ts
+++ b/src/lib/helpers.ts
@@ -1,4 +1,5 @@
 export const coalesceRowsToArray = (source: string, joinQuery: string) => {
+  // Note that array_to_json(array_agg(row_to_json())) seems to perform better than json_agg
   return `
 COALESCE(
   (