From b2e7b6fafb31082430494839ba502ebaef9ef9b1 Mon Sep 17 00:00:00 2001
From: Tanmoy Sarkar <57363826+tanmoysrt@users.noreply.github.com>
Date: Sat, 25 Oct 2025 19:12:25 +0530
Subject: [PATCH 1/2] fix(sqlite): Use DEFERRED isolation level

sqlite connection starts with no transaction if isolation level hasn't provided
---
 frappe/database/sqlite/database.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/frappe/database/sqlite/database.py b/frappe/database/sqlite/database.py
index 2bb21c9a76..6e02173239 100644
--- a/frappe/database/sqlite/database.py
+++ b/frappe/database/sqlite/database.py
@@ -105,7 +105,6 @@ class SQLiteDatabase(SQLiteExceptionUtil, Database):
 
 	def get_connection(self, read_only: bool = False):
 		conn = self.create_connection(read_only)
-		conn.isolation_level = None
 		conn.create_function("regexp", 2, regexp)
 		conn.create_function("regexp_replace", 3, regexp_replace)
 		pragmas = {

From 5ce54d0144bade7d9e3f3e5ac999f63e6fa7b1e2 Mon Sep 17 00:00:00 2001
From: Tanmoy Sarkar <57363826+tanmoysrt@users.noreply.github.com>
Date: Sat, 25 Oct 2025 21:28:08 +0530
Subject: [PATCH 2/2] feat(sqlite): Set 5s of busy_timeout

To reduce database lock issue during concurrent write / wal merge
---
 frappe/database/sqlite/database.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/frappe/database/sqlite/database.py b/frappe/database/sqlite/database.py
index 6e02173239..7ec508d7d5 100644
--- a/frappe/database/sqlite/database.py
+++ b/frappe/database/sqlite/database.py
@@ -110,6 +110,7 @@ class SQLiteDatabase(SQLiteExceptionUtil, Database):
 		pragmas = {
 			"journal_mode": "WAL",
 			"synchronous": "NORMAL",
+			"busy_timeout": 5000,  # in milliseconds
 		}
 		cursor = conn.cursor()
 		for pragma, value in pragmas.items():