From 3a9d37685194984605636ee31ccd5feeb625c888 Mon Sep 17 00:00:00 2001
From: Sean Ely <105326513+sean-tdengine@users.noreply.github.com>
Date: Mon, 22 Aug 2022 14:13:58 -0700
Subject: [PATCH] docs: Time-Series Extensions - added pseudocolumns

Added the _wstart, _wend, and _wduration pseudocolumns to the documentation.
---
 docs/en/12-taos-sql/12-distinguished.md | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/docs/en/12-taos-sql/12-distinguished.md b/docs/en/12-taos-sql/12-distinguished.md
index 7390fe983f..707089abe5 100644
--- a/docs/en/12-taos-sql/12-distinguished.md
+++ b/docs/en/12-taos-sql/12-distinguished.md
@@ -58,6 +58,15 @@ The following restrictions apply:
 - The window clause cannot be used with a GROUP BY clause.
 - `WHERE` clause can be used to specify the starting and ending time and other filter conditions
 
+
+### Window Pseudocolumns
+
+**\_WSTART, \_WEND, and \_WDURATION**
+
+The \_WSTART, \_WEND, and \_WDURATION pseudocolumns indicate the beginning, end, and duration of a window.
+
+These pseudocolumns occur after the aggregation clause.
+
 ### FILL Clause
 
 `FILL` clause is used to specify how to fill when there is data missing in any window, including: