From 95fd694eacc6133e0a588f180ac1a0514933879e Mon Sep 17 00:00:00 2001
From: Sattvik Chakravarthy <sattvik@gmail.com>
Date: Thu, 21 Mar 2024 13:06:26 +0530
Subject: [PATCH] fix: user pagination

---
 CHANGELOG.md                                  |  1 +
 .../storage/mysql/queries/GeneralQueries.java | 22 ++++++++++++++-----
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 353e21b..6b8a31a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,7 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 - Adds a new `useStaticKey` param to `updateSessionInfo_Transaction`
   - This enables smooth switching between `useDynamicAccessTokenSigningKey` settings by allowing refresh calls to
     change the signing key type of a session
+- Fixes performance issue with user pagination
 
 ## [6.0.0] - 2024-03-05
 
diff --git a/src/main/java/io/supertokens/storage/mysql/queries/GeneralQueries.java b/src/main/java/io/supertokens/storage/mysql/queries/GeneralQueries.java
index ba88f54..01b884b 100644
--- a/src/main/java/io/supertokens/storage/mysql/queries/GeneralQueries.java
+++ b/src/main/java/io/supertokens/storage/mysql/queries/GeneralQueries.java
@@ -786,7 +786,7 @@ public static AuthRecipeUserInfo[] getUsers(Start start, TenantIdentifier tenant
                 } else {
 
                     String finalQuery = "SELECT DISTINCT primary_or_recipe_user_id, primary_or_recipe_user_time_joined  FROM ( " + USER_SEARCH_TAG_CONDITION.toString() + " )"
-                            + " AS finalResultTable ORDER BY primary_or_recipe_user_time_joined " + timeJoinedOrder + ", primary_or_recipe_user_id DESC ";
+                            + " AS finalResultTable ORDER BY primary_or_recipe_user_time_joined " + timeJoinedOrder + ", primary_or_recipe_user_id " + timeJoinedOrder;
                     usersFromQuery = execute(start, finalQuery, pst -> {
                         for (int i = 1; i <= queryList.size(); i++) {
                             pst.setString(i, queryList.get(i - 1));
@@ -822,11 +822,17 @@ public static AuthRecipeUserInfo[] getUsers(Start start, TenantIdentifier tenant
                     recipeIdCondition = recipeIdCondition + " AND";
                 }
                 String timeJoinedOrderSymbol = timeJoinedOrder.equals("ASC") ? ">" : "<";
-                String QUERY = "SELECT DISTINCT primary_or_recipe_user_id, primary_or_recipe_user_time_joined FROM " + Config.getConfig(start).getUsersTable() + " WHERE "
+
+                // This query is slightly different from one in postgres because we want to use same ordering for
+                // primary_or_recipe_user_time_joined and primary_or_recipe_user_id because mysql 5.7 does not support
+                // different ordering for different columns using an index
+                String QUERY = "SELECT DISTINCT primary_or_recipe_user_id, primary_or_recipe_user_time_joined FROM "
+                        + Config.getConfig(start).getUsersTable() + " WHERE "
                         + recipeIdCondition + " (primary_or_recipe_user_time_joined " + timeJoinedOrderSymbol
-                        + " ? OR (primary_or_recipe_user_time_joined = ? AND primary_or_recipe_user_id <= ?)) AND app_id = ? AND tenant_id = ?"
+                        + " ? OR (primary_or_recipe_user_time_joined = ? AND primary_or_recipe_user_id "
+                        + (timeJoinedOrderSymbol + "=") + " ?)) AND app_id = ? AND tenant_id = ?"
                         + " ORDER BY primary_or_recipe_user_time_joined " + timeJoinedOrder
-                        + ", primary_or_recipe_user_id DESC LIMIT ?";
+                        + ", primary_or_recipe_user_id " + timeJoinedOrder + " LIMIT ?";
                 usersFromQuery = execute(start, QUERY, pst -> {
                     if (includeRecipeIds != null) {
                         for (int i = 0; i < includeRecipeIds.length; i++) {
@@ -850,12 +856,16 @@ public static AuthRecipeUserInfo[] getUsers(Start start, TenantIdentifier tenant
                 });
             } else {
                 String recipeIdCondition = RECIPE_ID_CONDITION.toString();
-                String QUERY = "SELECT DISTINCT primary_or_recipe_user_id, primary_or_recipe_user_time_joined FROM " + Config.getConfig(start).getUsersTable() + " WHERE ";
+                // This query is slightly different from one in postgres because we want to use same ordering for
+                // primary_or_recipe_user_time_joined and primary_or_recipe_user_id because mysql 5.7 does not support
+                // different ordering for different columns using an index
+                String QUERY = "SELECT DISTINCT primary_or_recipe_user_id, primary_or_recipe_user_time_joined FROM "
+                        + Config.getConfig(start).getUsersTable() + " WHERE ";
                 if (!recipeIdCondition.equals("")) {
                     QUERY += recipeIdCondition + " AND";
                 }
                 QUERY += " app_id = ? AND tenant_id = ? ORDER BY primary_or_recipe_user_time_joined " + timeJoinedOrder
-                        + ", primary_or_recipe_user_id DESC LIMIT ?";
+                        + ", primary_or_recipe_user_id " + timeJoinedOrder + " LIMIT ?";
                 usersFromQuery = execute(start, QUERY, pst -> {
                     if (includeRecipeIds != null) {
                         for (int i = 0; i < includeRecipeIds.length; i++) {