From 506f800eadea2ab8c9d90f00278b4b03f3a9b771 Mon Sep 17 00:00:00 2001
From: Mariusz Felisiak <felisiak.mariusz@gmail.com>
Date: Fri, 19 Jul 2019 13:05:31 +0200
Subject: [PATCH] [2.2.x] Refs #30083 -- Added a warning about performing
 queries in pre/post_init receivers.

Thanks Carlton Gibson the review.

Backport of fc1182af01c391ce33d7fcf51c756829c6a11d5b from master
---
 docs/ref/signals.txt | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/docs/ref/signals.txt b/docs/ref/signals.txt
index a89560cc1e6..19a92a875c4 100644
--- a/docs/ref/signals.txt
+++ b/docs/ref/signals.txt
@@ -106,6 +106,12 @@ Arguments sent with this signal:
         ``_state.db`` is ``None`` and cannot be used to check an ``instance``
         database.
 
+.. warning::
+
+    For performance reasons, you shouldn't perform queries in receivers of
+    ``pre_init`` or ``post_init`` signals because they would be executed for
+    each instance returned during queryset iteration.
+
 ``pre_save``
 ------------