perf: Cache db columns to avoid redundant database calls (#8543)

* perf: Cache db columns to avoid redundant database calls

* fix: Move cache clearing code from doctype to schema.py

* fix: self.table_name instead of self.name

* fix: Cache columns in  "table_columns" key

`table_columns` was cached in meta but columns were also getting accessed
directly using frappe.db.get_table_columns. Now, it is cached at
`frappe.db` layer

Co-authored-by: Suraj Shetty <surajshetty3416@gmail.com>

frappe/core/doctype/doctype/doctype.py

@@ -312,7 +312,6 @@ class DocType(Document):
 
 		clear_linked_doctype_cache()
 
-
 	def delete_duplicate_custom_fields(self):
 		if not (frappe.db.table_exists(self.name) and frappe.db.table_exists("Custom Field")):
 			return

frappe/database/database.py

@@ -845,10 +845,17 @@ class Database(object):
 
 	def get_db_table_columns(self, table):
 		"""Returns list of column names from given table."""
-		return [r[0] for r in self.sql('''
-			select column_name
-			from information_schema.columns
-			where table_name = %s ''', table)]
+		columns = frappe.cache().hget('table_columns', table)
+		if columns is None:
+			columns = [r[0] for r in self.sql('''
+				select column_name
+				from information_schema.columns
+				where table_name = %s ''', table)]
+
+			if columns:
+				frappe.cache().hset('table_columns', table, columns)
+
+		return columns
 
 	def get_table_columns(self, doctype):
 		"""Returns list of column names from given doctype."""

frappe/database/mariadb/framework_mariadb.sql

@@ -49,6 +49,12 @@ CREATE TABLE `tabDocField` (
   `default` text,
   `description` text,
   `in_list_view` int(1) NOT NULL DEFAULT 0,
+  `fetch_if_empty` int(1) NOT NULL DEFAULT 0,
+  `in_filter` int(1) NOT NULL DEFAULT 0,
+  `remember_last_selected_value` int(1) NOT NULL DEFAULT 0,
+  `ignore_xss_filter` int(1) NOT NULL DEFAULT 0,
+  `print_hide_if_no_value` int(1) NOT NULL DEFAULT 0,
+  `allow_bulk_edit` int(1) NOT NULL DEFAULT 0,
   `in_standard_filter` int(1) NOT NULL DEFAULT 0,
   `in_preview` int(1) NOT NULL DEFAULT 0,
   `read_only` int(1) NOT NULL DEFAULT 0,

frappe/database/postgres/framework_postgres.sql

@@ -49,6 +49,12 @@ CREATE TABLE "tabDocField" (
   "default" text,
   "description" text,
   "in_list_view" smallint NOT NULL DEFAULT 0,
+  "fetch_if_empty" smallint NOT NULL DEFAULT 0,
+  "in_filter" smallint NOT NULL DEFAULT 0,
+  "remember_last_selected_value" smallint NOT NULL DEFAULT 0,
+  "ignore_xss_filter" smallint NOT NULL DEFAULT 0,
+  "print_hide_if_no_value" smallint NOT NULL DEFAULT 0,
+  "allow_bulk_edit" smallint NOT NULL DEFAULT 0,
   "in_standard_filter" smallint NOT NULL DEFAULT 0,
   "in_preview" smallint NOT NULL DEFAULT 0,
   "read_only" smallint NOT NULL DEFAULT 0,

frappe/database/schema.py

@@ -33,6 +33,7 @@ class DBTable:
 		if self.is_new():
 			self.create()
 		else:
+			frappe.cache().hdel('table_columns', self.table_name)
 			self.alter()
 
 	def create(self):

frappe/model/meta.py

@@ -46,8 +46,7 @@ def load_meta(doctype):
 	return Meta(doctype)
 
 def get_table_columns(doctype):
-	return frappe.cache().hget("table_columns", doctype,
-		lambda: frappe.db.get_table_columns(doctype))
+	return frappe.db.get_table_columns(doctype)
 
 def load_doctype_from_file(doctype):
 	fname = frappe.scrub(doctype)