feat: estimate table size

frappe/database/database.py

@@ -1250,6 +1250,10 @@ class Database:
 			frappe.cache.set_value(f"doctype:count:{dt}", count, expires_in_sec=86400)
 		return count
 
+	def estimate_count(self, doctype: str) -> int:
+		"""Get estimated count of total rows in a table."""
+		raise NotImplementedError
+
 	@staticmethod
 	def format_date(date):
 		return getdate(date).strftime("%Y-%m-%d")

frappe/database/mariadb/database.py

@@ -541,3 +541,12 @@ class MariaDBDatabase(MariaDBConnectionUtil, MariaDBExceptionUtil, Database):
 		finally:
 			self._cursor = original_cursor
 			new_cursor.close()
+
+	def estimate_count(self, doctype: str):
+		"""Get estimated count of total rows in a table."""
+		from frappe.utils.data import cint
+
+		table = get_table_name(doctype)
+
+		count = self.sql("select table_rows from information_schema.tables where table_name = %s", table)
+		return cint(count[0][0]) if count else 0

frappe/database/postgres/database.py

@@ -483,6 +483,14 @@ class PostgresDatabase(PostgresExceptionUtil, Database):
 	def get_database_list(self):
 		return self.sql("SELECT datname FROM pg_database", pluck=True)
 
+	def estimate_count(self, doctype: str):
+		"""Get estimated count of total rows in a table."""
+		from frappe.utils.data import cint
+
+		table = get_table_name(doctype)
+		count = self.sql("select reltuples from pg_class where relname = %s", table)
+		return cint(count[0][0]) if count else 0
+
 
 def modify_query(query):
 	""" "Modifies query according to the requirements of postgres"""

frappe/tests/test_db.py

@@ -510,6 +510,9 @@ class TestDB(IntegrationTestCase):
 
 		self.assertEqual(frappe.db.exists(dt, [["name", "=", dn]]), dn)
 
+	def test_estimated_count(self):
+		self.assertGreater(frappe.db.estimate_count("DocField"), 100)
+
 	def test_datetime_serialization(self):
 		dt = now_datetime()
 		dt = dt.replace(microsecond=0)