From fb5ef3422cb5e581c20ac55489a388471de9b186 Mon Sep 17 00:00:00 2001
From: Hongbo Wu <hongbo@omnivore.app>
Date: Wed, 12 Jun 2024 19:09:40 +0800
Subject: [PATCH] commit the delete query for each user in the loop to reduce
 lock time

---
 .../0181.do.batch_delete_trash_items.sql      | 24 +++++++++++++++++--
 .../0181.undo.batch_delete_trash_items.sql    |  2 +-
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/packages/db/migrations/0181.do.batch_delete_trash_items.sql b/packages/db/migrations/0181.do.batch_delete_trash_items.sql
index 07b38d538..3657610ae 100755
--- a/packages/db/migrations/0181.do.batch_delete_trash_items.sql
+++ b/packages/db/migrations/0181.do.batch_delete_trash_items.sql
@@ -4,7 +4,9 @@
 
 BEGIN;
 
-CREATE OR REPLACE FUNCTION batch_delete_trash_items()
+CREATE OR REPLACE PROCEDURE batch_delete_trash_items(
+    minimum_items INT
+)
 RETURNS VOID AS $$
 DECLARE
     user_record RECORD;
@@ -17,14 +19,32 @@ DECLARE
         status = 'ACTIVE';
 BEGIN
     FOR user_record IN user_cursor LOOP
+        BEGIN;
+        
         -- For Row Level Security
         PERFORM omnivore.set_claims(user_record.id, 'omnivore_user');
 
+        -- keep the minimum number of items in trash
         DELETE FROM omnivore.library_item
         WHERE
             user_id = user_record.id
             AND state = 'DELETED'
-            AND deleted_at < NOW() - INTERVAL '14 days';
+            AND deleted_at < NOW() - INTERVAL '14 days'
+            AND id NOT IN (
+                SELECT
+                    id
+                FROM
+                    omnivore.library_item
+                WHERE
+                    user_id = user_record.id
+                    AND state = 'DELETED'
+                    AND deleted_at < NOW() - INTERVAL '14 days'
+                ORDER BY
+                    deleted_at DESC
+                LIMIT minimum_items
+            );
+
+        COMMIT;
     END LOOP;
 END;
 $$ LANGUAGE plpgsql;
diff --git a/packages/db/migrations/0181.undo.batch_delete_trash_items.sql b/packages/db/migrations/0181.undo.batch_delete_trash_items.sql
index 836f8e533..3851c057b 100755
--- a/packages/db/migrations/0181.undo.batch_delete_trash_items.sql
+++ b/packages/db/migrations/0181.undo.batch_delete_trash_items.sql
@@ -4,6 +4,6 @@
 
 BEGIN;
 
-DROP FUNCTION IF EXISTS batch_delete_trash_items();
+DROP PROCEDURE IF EXISTS batch_delete_trash_items();
 
 COMMIT;