From 88a96be8968bce131463a5108aabde228cb4e339 Mon Sep 17 00:00:00 2001
From: Sergey Shcherbina <sshcherbina@coursera.org>
Date: Thu, 31 Mar 2022 16:28:05 +0500
Subject: [PATCH] GUACAMOLE-1488: Slow selection of users on scale on Postgres

---
 .../guacamole/auth/jdbc/user/UserMapper.xml   | 21 +++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-postgresql/src/main/resources/org/apache/guacamole/auth/jdbc/user/UserMapper.xml b/extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-postgresql/src/main/resources/org/apache/guacamole/auth/jdbc/user/UserMapper.xml
index 94d607e337..bcd5159e17 100644
--- a/extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-postgresql/src/main/resources/org/apache/guacamole/auth/jdbc/user/UserMapper.xml
+++ b/extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-postgresql/src/main/resources/org/apache/guacamole/auth/jdbc/user/UserMapper.xml
@@ -126,10 +126,13 @@
             email_address,
             organization,
             organizational_role,
-            MAX(start_date) AS last_active
+            (SELECT start_date
+             FROM guacamole_user_history
+             WHERE user_id = guacamole_user.user_id
+             ORDER BY start_date desc
+             LIMIT 1) AS last_active
         FROM guacamole_user
         JOIN guacamole_entity ON guacamole_user.entity_id = guacamole_entity.entity_id
-        LEFT JOIN guacamole_user_history ON guacamole_user_history.user_id = guacamole_user.user_id
         WHERE guacamole_entity.name IN
             <foreach collection="identifiers" item="identifier"
                      open="(" separator="," close=")">
@@ -176,10 +179,13 @@
             email_address,
             organization,
             organizational_role,
-            MAX(start_date) AS last_active
+            (SELECT start_date
+             FROM guacamole_user_history
+             WHERE user_id = guacamole_user.user_id
+             ORDER BY start_date desc
+             LIMIT 1) AS last_active
         FROM guacamole_user
         JOIN guacamole_entity ON guacamole_user.entity_id = guacamole_entity.entity_id
-        LEFT JOIN guacamole_user_history ON guacamole_user_history.user_id = guacamole_user.user_id
         WHERE guacamole_entity.name IN
             <foreach collection="identifiers" item="identifier"
                      open="(" separator="," close=")">
@@ -238,10 +244,13 @@
             email_address,
             organization,
             organizational_role,
-            MAX(start_date) AS last_active
+            (SELECT start_date
+             FROM guacamole_user_history
+             WHERE user_id = guacamole_user.user_id
+             ORDER BY start_date desc
+             LIMIT 1) AS last_active
         FROM guacamole_user
         JOIN guacamole_entity ON guacamole_user.entity_id = guacamole_entity.entity_id
-        LEFT JOIN guacamole_user_history ON guacamole_user_history.user_id = guacamole_user.user_id
         WHERE
             guacamole_entity.name = #{username,jdbcType=VARCHAR}
             AND guacamole_entity.type = 'USER'::guacamole_entity_type