# HG changeset patch
# User Tom Gottfried <tom@intevation.de>
# Date 1584368353 -3600
# Node ID 6fe3662aafebc5611fbaf67d227eef3adb8fc997
# Parent  e4ab338e7ba97307c5f80269136705276c0b8fde
Add explaining comment

Since the commented filter condition logically adds nothing to
the WHERE clause here, explain why it's there.

diff -r e4ab338e7ba9 -r 6fe3662aafeb pkg/imports/wx.go
--- a/pkg/imports/wx.go	Sat Mar 14 20:11:10 2020 +0100
+++ b/pkg/imports/wx.go	Mon Mar 16 15:19:13 2020 +0100
@@ -61,6 +61,9 @@
 ),
 t AS (
   UPDATE waterway.waterway_axis SET last_found = current_timestamp
+  -- The first condition is just to help the PostgreSQL query planner
+  -- to avoid evaluating more costly conditions including those
+  -- introduced by row level security policies:
   WHERE (SELECT new_ax FROM g) IS NOT NULL
     AND validity @> current_timestamp
     AND (