diff --git a/.github/chore/compose.content.yaml b/.github/chore/compose.content.yaml
index 0ab3622c..61d1f110 100644
--- a/.github/chore/compose.content.yaml
+++ b/.github/chore/compose.content.yaml
@@ -29,7 +29,7 @@ services:
       timeout: 20s
       retries: 10
   redis:
-    image: redis:7.2.3-alpine3.18
+    image: valkey/valkey:7.2.7-alpine3.20
     ports:
       - 6379:6379
     volumes:
@@ -41,7 +41,7 @@ services:
       - 50051:50051
       - 8088:8088
     depends_on:
-      mysql:
+      postgres:
         condition: service_healthy
       db1:
         condition: service_healthy
@@ -52,20 +52,19 @@ services:
     image: sixwaaaay/graph:v0.5.0
     ports:
       - 8080:8080
-  mysql:
-    image: mysql:8.2.0
+  postgres:
+    image: postgres:17.0-bookworm
     environment:
-      MYSQL_ROOT_PASSWORD: root
-      MYSQL_DATABASE: content
-      MYSQL_USER: mysql_user
-      MYSQL_PASSWORD: mysql
+      POSTGRES_USER: postgres
+      POSTGRES_PASSWORD: postgres
+      POSTGRES_DB: postgres
     ports:
-      - 33306:3306
+      - 5432:5432
     volumes:
       - ./content.sql:/docker-entrypoint-initdb.d/content.sql
-      - mysql-data:/var/lib/mysql
+      - postgres-data:/var/lib/postgresql/data
     healthcheck:
-      test: [ "CMD", "mysqladmin", "ping", "-h", "localhost" ]
+      test: [ "CMD", "pg_isready", "-U", "postgres" ]
       timeout: 20s
       retries: 10
   jaeger:
@@ -75,6 +74,6 @@ services:
       - 16686:16686
 
 volumes:
-  mysql-data:
+  postgres-data:
   redis-data:
   db1-data:
\ No newline at end of file
diff --git a/.github/chore/content.sql b/.github/chore/content.sql
index 8e17cbe5..f90a545b 100644
--- a/.github/chore/content.sql
+++ b/.github/chore/content.sql
@@ -12,107 +12,96 @@
  */
 
 
-CREATE TABLE `notifications`
+CREATE TABLE notifications
 (
-    `id`          BIGINT       NOT NULL AUTO_INCREMENT,
-    `sender_id`   BIGINT       NOT NULL,
-    `receiver_id` BIGINT       NOT NULL,
-    `content`     varchar(255) NOT NULL,
-    `type`        TINYINT unsigned NOT NULL DEFAULT 0,
-    `status`      TINYINT unsigned NOT NULL DEFAULT 0,
-    `created_at`  TIMESTAMP    NOT NULL DEFAULT CURRENT_TIMESTAMP,
-    PRIMARY KEY (`id`),
-    KEY           `query_by_receiver_id` (`status`,`receiver_id`,`id` ASC)
-) ENGINE=InnoDB
-  DEFAULT CHARSET=utf8mb4
-  COLLATE=utf8mb4_0900_ai_ci;
+    id          BIGSERIAL    PRIMARY KEY,
+    sender_id   BIGINT       NOT NULL,
+    receiver_id BIGINT       NOT NULL,
+    content     VARCHAR(255) NOT NULL,
+    type        SMALLINT     NOT NULL DEFAULT 0,
+    status      SMALLINT     NOT NULL DEFAULT 0,
+    created_at  TIMESTAMP    NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
+
+CREATE INDEX query_by_receiver_id 
+    ON notifications (status, receiver_id, id ASC);
 
 CREATE TABLE videos
 (
-    id         BIGINT       NOT NULL AUTO_INCREMENT,
+    id         BIGSERIAL    PRIMARY KEY,
     user_id    BIGINT       NOT NULL,
     title      VARCHAR(255) NOT NULL,
     des        VARCHAR(255) NOT NULL,
-    cover_url  VARCHAR(255) NOT NULL default '',
-    video_url  VARCHAR(255) NOT NULL default '',
-    duration   INT UNSIGNED,
-    view_count INT UNSIGNED NOT NULL DEFAULT 0,
-    like_count INT UNSIGNED NOT NULL DEFAULT 0,
+    cover_url  VARCHAR(255) NOT NULL DEFAULT '',
+    video_url  VARCHAR(255) NOT NULL DEFAULT '',
+    duration   INTEGER      NOT NULL DEFAULT 0,
+    view_count INTEGER      NOT NULL DEFAULT 0,
+    like_count INTEGER      NOT NULL DEFAULT 0,
     created_at TIMESTAMP    NOT NULL DEFAULT CURRENT_TIMESTAMP,
-    updated_at TIMESTAMP    NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
-    processed  TINYINT      NOT NULL DEFAULT 0,
-    PRIMARY KEY (id),
-    KEY        `user_created` (`processed`, `user_id`, `id` DESC),
-    KEY        `processed` (`processed`, `id` DESC)
-) ENGINE = InnoDB
-  DEFAULT CHARSET = utf8mb4
-  COLLATE = utf8mb4_unicode_ci;
+    updated_at TIMESTAMP    NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    processed  SMALLINT     NOT NULL DEFAULT 0
+);
 
-CREATE TABLE counter
-(
-    id      BIGINT NOT NULL,
-    counter INT UNSIGNED NOT NULL DEFAULT 0,
-    PRIMARY KEY (id)
-) ENGINE = InnoDB
-  DEFAULT CHARSET = utf8mb4
-  COLLATE = utf8mb4_unicode_ci;
 
-INSERT INTO content.videos (id, user_id, title, des, cover_url, video_url, duration, view_count, like_count, created_at, updated_at, processed)
-VALUES  (1, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 01:12:27', '2023-12-31 01:12:27', 1),
-        (2, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 01:13:02', '2023-12-31 01:13:02', 1),
-        (3, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 01:13:19', '2023-12-31 01:13:19', 1),
-        (4, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 01:14:18', '2023-12-31 01:14:18', 1),
-        (5, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 12:05:07', '2023-12-31 12:05:07', 1),
-        (6, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 12:05:23', '2023-12-31 12:05:23', 1),
-        (7, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 12:42:53', '2023-12-31 12:42:53', 1),
-        (8, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 12:43:40', '2023-12-31 12:43:40', 1),
-        (9, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 12:53:18', '2023-12-31 12:53:18', 1),
-        (10, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 12:53:58', '2023-12-31 12:53:58', 1),
-        (11, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 13:08:05', '2023-12-31 13:08:05', 1),
-        (12, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 13:55:52', '2023-12-31 13:55:52', 1),
-        (13, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 13:56:22', '2023-12-31 13:56:22', 1),
-        (14, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:01:47', '2023-12-31 14:01:47', 1),
-        (15, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:02:10', '2023-12-31 14:02:10', 1),
-        (16, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:02:22', '2023-12-31 14:02:22', 1),
-        (17, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:02:42', '2023-12-31 14:02:42', 1),
-        (18, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:08:44', '2023-12-31 14:08:44', 1),
-        (19, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:09:13', '2023-12-31 14:09:13', 1),
-        (20, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:10:04', '2023-12-31 14:10:04', 1),
-        (21, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:10:48', '2023-12-31 14:10:48', 1),
-        (22, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:17:40', '2023-12-31 14:17:40', 1),
-        (23, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:32:50', '2023-12-31 14:32:50', 1),
-        (24, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:33:19', '2023-12-31 14:33:19', 1),
-        (25, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:41:41', '2023-12-31 14:41:41', 1),
-        (26, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:46:15', '2023-12-31 14:46:15', 1),
-        (27, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 22:03:32', '2023-12-31 22:03:32', 1),
-        (28, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 23:22:43', '2023-12-31 23:22:43', 1),
-        (29, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 23:23:05', '2023-12-31 23:23:05', 1),
-        (30, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 23:55:59', '2023-12-31 23:55:59', 1),
-        (31, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2024-01-01 14:51:46', '2024-01-01 14:51:46', 1),
-        (32, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2024-01-01 14:52:38', '2024-01-01 14:52:38', 1),
-        (33, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2024-01-01 14:52:49', '2024-01-01 14:52:49', 1),
-        (34, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2024-01-01 14:53:01', '2024-01-01 14:53:01', 1),
-        (35, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2024-01-01 15:10:38', '2024-01-01 15:10:38', 1),
-        (36, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2024-01-01 19:51:31', '2024-01-01 19:51:31', 1),
-        (37, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2024-01-01 20:15:07', '2024-01-01 20:15:07', 1),
-        (38, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2024-01-01 20:17:29', '2024-01-01 20:17:29', 1),
-        (39, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2024-01-02 14:11:43', '2024-01-02 14:11:43', 1),
-        (40, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2024-01-02 14:12:04', '2024-01-02 14:12:04', 1),
-        (41, 1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2024-01-02 15:36:48', '2024-01-02 15:36:48', 1);
+CREATE INDEX user_created
+    ON videos (processed, user_id, id DESC);
+CREATE INDEX processed
+    ON videos (processed, id DESC);
+
 
-INSERT INTO content.counter (id, counter)
-SELECT videos.user_id, count(*) FROM videos GROUP BY videos.user_id;
+INSERT INTO videos (user_id, title, des, cover_url, video_url, duration, view_count, like_count, created_at, updated_at, processed)
+VALUES  (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 01:12:27', '2023-12-31 01:12:27', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 01:13:02', '2023-12-31 01:13:02', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 01:13:19', '2023-12-31 01:13:19', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 01:14:18', '2023-12-31 01:14:18', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 12:05:07', '2023-12-31 12:05:07', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 12:05:23', '2023-12-31 12:05:23', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 12:42:53', '2023-12-31 12:42:53', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 12:43:40', '2023-12-31 12:43:40', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 12:53:18', '2023-12-31 12:53:18', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 12:53:58', '2023-12-31 12:53:58', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 13:08:05', '2023-12-31 13:08:05', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 13:55:52', '2023-12-31 13:55:52', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 13:56:22', '2023-12-31 13:56:22', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:01:47', '2023-12-31 14:01:47', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:02:10', '2023-12-31 14:02:10', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:02:22', '2023-12-31 14:02:22', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:02:42', '2023-12-31 14:02:42', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:08:44', '2023-12-31 14:08:44', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:09:13', '2023-12-31 14:09:13', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:10:04', '2023-12-31 14:10:04', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:10:48', '2023-12-31 14:10:48', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:17:40', '2023-12-31 14:17:40', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:32:50', '2023-12-31 14:32:50', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:33:19', '2023-12-31 14:33:19', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:41:41', '2023-12-31 14:41:41', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 14:46:15', '2023-12-31 14:46:15', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 22:03:32', '2023-12-31 22:03:32', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 23:22:43', '2023-12-31 23:22:43', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 23:23:05', '2023-12-31 23:23:05', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2023-12-31 23:55:59', '2023-12-31 23:55:59', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2024-01-01 14:51:46', '2024-01-01 14:51:46', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2024-01-01 14:52:38', '2024-01-01 14:52:38', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2024-01-01 14:52:49', '2024-01-01 14:52:49', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2024-01-01 14:53:01', '2024-01-01 14:53:01', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2024-01-01 15:10:38', '2024-01-01 15:10:38', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2024-01-01 19:51:31', '2024-01-01 19:51:31', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2024-01-01 20:15:07', '2024-01-01 20:15:07', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2024-01-01 20:17:29', '2024-01-01 20:17:29', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2024-01-02 14:11:43', '2024-01-02 14:11:43', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2024-01-02 14:12:04', '2024-01-02 14:12:04', 1),
+        (1, 'title', 'des', 'coverUrl', 'videoUrl', 1, 1, 1, '2024-01-02 15:36:48', '2024-01-02 15:36:48', 1);
 
 CREATE TABLE popular_videos
 (
-    order_num BIGINT NOT NULL
+    id        BIGINT NOT NULL
         PRIMARY KEY,
-    id        BIGINT NULL,
-    score     DOUBLE NULL
+    order_num BIGINT NOT NULL,
+    score     DOUBLE PRECISION NULL
 );
 
 
-
 INSERT INTO popular_videos (id, order_num, score)
 VALUES  ('16', 1, 90.077423201946),
         ('38', 2, 89.7837850170059),
diff --git a/.github/workflows/content.yaml b/.github/workflows/content.yaml
index ec1da3fb..aa08fd7c 100644
--- a/.github/workflows/content.yaml
+++ b/.github/workflows/content.yaml
@@ -59,7 +59,7 @@ jobs:
           dotnet test --collect "Code Coverage;Format=cobertura"
           dotnet-coverage merge -o merged.cobertura.xml -f cobertura TestResults/**/*.cobertura.xml
         env:
-          CONNECTION_STRING: "server=localhost;port=33306;database=content;user=mysql_user;password=mysql;SslMode=none;Max Pool Size=2;AllowPublicKeyRetrieval=True; "
+          CONNECTION_STRING: "Host=localhost; Port=5432; Username=postgres; Password=postgres; Database=postgres; Maximum Pool Size=25;"
           USER_STRING: "http://localhost:50051"
           VOTE_STRING: "http://localhost:8080"
           FFPROBE_PATH: "/usr/bin/ffprobe"
diff --git a/sharp/content.Tests/UnitTest.cs b/sharp/content.Tests/UnitTest.cs
index 2cbd9828..575ae4d5 100644
--- a/sharp/content.Tests/UnitTest.cs
+++ b/sharp/content.Tests/UnitTest.cs
@@ -14,7 +14,7 @@
 
 using content.repository;
 using JetBrains.Annotations;
-using MySqlConnector;
+using Npgsql;
 using Xunit.Abstractions;
 
 namespace content.Tests;
@@ -27,7 +27,7 @@ public class UnitTest(ITestOutputHelper testOutputHelper)
     [Fact(DisplayName = "Video Repository")]
     public async void Test1()
     {
-        await using var dataSource = new MySqlDataSource(_connectString);
+        await using var dataSource = NpgsqlDataSource.Create(_connectString);
         var videoRepository = (IVideoRepository)new VideoRepository(dataSource);
         var video = new Video
         {
@@ -40,8 +40,8 @@ public async void Test1()
             Duration = 1,
             ViewCount = 1,
             LikeCount = 1,
-            CreatedAt = DateTime.Now,
-            UpdatedAt = DateTime.Now,
+            CreatedAt = DateTime.UtcNow,
+            UpdatedAt = DateTime.UtcNow,
             Processed = 1
         };
         video = await videoRepository.Save(video);
@@ -79,7 +79,7 @@ public async void Test1()
     [Fact(DisplayName = "Command")]
     public async void TestInsert()
     {
-        await using var dataSource = new MySqlDataSource(_connectString);
+        await using var dataSource = NpgsqlDataSource.Create(_connectString);
         var videoRepository = (IVideoRepository)new VideoRepository(dataSource);
         var video = new Video
         {
@@ -92,8 +92,8 @@ public async void TestInsert()
             Duration = 1,
             ViewCount = 1,
             LikeCount = 1,
-            CreatedAt = DateTime.Now,
-            UpdatedAt = DateTime.Now,
+            CreatedAt = DateTime.UtcNow,
+            UpdatedAt = DateTime.UtcNow,
             Processed = 1
         };
         video = await videoRepository.Save(video);
@@ -105,7 +105,7 @@ public async Task Test3()
     {
         var now = DateTime.Now;
         var tasks = new List<Task>();
-        await using var dataSource = new MySqlDataSource(_connectString);
+        await using var dataSource = NpgsqlDataSource.Create(_connectString);
         for (var i = 0; i < 10000; i++)
         {
             var videoRepository = new VideoRepository(dataSource);
diff --git a/sharp/content.Tests/repository/NotificationRepositoryTest.cs b/sharp/content.Tests/repository/NotificationRepositoryTest.cs
index 53e2230e..5207e2eb 100644
--- a/sharp/content.Tests/repository/NotificationRepositoryTest.cs
+++ b/sharp/content.Tests/repository/NotificationRepositoryTest.cs
@@ -13,8 +13,8 @@
  */
 
 
-using MySqlConnector;
 using content.repository;
+using Npgsql;
 
 namespace content.Tests.repository;
 public class NotificationRepositoryTests
@@ -23,7 +23,7 @@ public class NotificationRepositoryTests
 
     public NotificationRepositoryTests()
     {
-        var dataSource = new MySqlDataSource(Environment.GetEnvironmentVariable("CONNECTION_STRING") !);
+        var dataSource = NpgsqlDataSource.Create(Environment.GetEnvironmentVariable("CONNECTION_STRING") !);
         _repository = new NotificationRepository(dataSource);
     }
 
diff --git a/sharp/content/Program.cs b/sharp/content/Program.cs
index 928cdd53..a6d84a04 100644
--- a/sharp/content/Program.cs
+++ b/sharp/content/Program.cs
@@ -20,7 +20,7 @@
 using content.repository;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.IdentityModel.Tokens;
-using MySqlConnector;
+using Npgsql;
 using OpenTelemetry.Metrics;
 using OpenTelemetry.Resources;
 using OpenTelemetry.Trace;
@@ -51,7 +51,7 @@
 builder.Services.AddOpenTelemetry().WithTracing(tcb =>
 {
     tcb
-        .AddSource(serviceName).AddSource("MySqlConnector")
+        .AddSource(serviceName).AddNpgsql()
         .SetResourceBuilder(ResourceBuilder.CreateDefault().AddService(serviceName: serviceName))
         .AddHttpClientInstrumentation()
         .AddGrpcClientInstrumentation()
@@ -66,7 +66,7 @@
 }).WithMetrics(mtb =>
 {
     mtb
-        .AddMeter("Microsoft.AspNetCore.Hosting", "Microsoft.AspNetCore.Server.Kestrel", "MySqlConnector")
+        .AddMeter("Microsoft.AspNetCore.Hosting", "Microsoft.AspNetCore.Server.Kestrel", "Npgsql")
         .AddAspNetCoreInstrumentation()
         .AddHttpClientInstrumentation()
         .AddPrometheusExporter();
@@ -78,7 +78,7 @@
 builder.Services.AddAuthorization().AddProbe();
 builder.Services.AddProblemDetails().AddResponseCompression();
 
-builder.Services.AddMySqlDataSource(builder.Configuration.GetConnectionString("Default") ??
+builder.Services.AddNpgsqlDataSource(builder.Configuration.GetConnectionString("Default") ??
                                     throw new InvalidOperationException("Connection string is null"));
 builder.Services.AddVideoRepository().AddNotificationRepository();
 
diff --git a/sharp/content/content.csproj b/sharp/content/content.csproj
index ab25e8f5..7547978e 100644
--- a/sharp/content/content.csproj
+++ b/sharp/content/content.csproj
@@ -40,8 +40,9 @@
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
-    <PackageReference Include="MySqlConnector" Version="2.3.3" />
-    <PackageReference Include="MySqlConnector.DependencyInjection" Version="2.3.1" />
+    <PackageReference Include="npgsql" Version="8.0.5" />
+    <PackageReference Include="Npgsql.DependencyInjection" Version="8.0.5" />
+    <PackageReference Include="Npgsql.OpenTelemetry" Version="8.0.5" />
     <PackageReference Include="OpenTelemetry.Exporter.OpenTelemetryProtocol" Version="1.7.0" />
     <PackageReference Include="OpenTelemetry.Exporter.Prometheus.AspNetCore" Version="1.7.0-rc.1" />
     <PackageReference Include="OpenTelemetry.Extensions.Hosting" Version="1.7.0" />
diff --git a/sharp/content/repository/Content.cs b/sharp/content/repository/Content.cs
index db70bca6..fd576036 100644
--- a/sharp/content/repository/Content.cs
+++ b/sharp/content/repository/Content.cs
@@ -13,7 +13,7 @@
  */
 
 using Dapper;
-using MySqlConnector;
+using Npgsql;
 
 [module: DapperAot]
 
@@ -29,7 +29,6 @@ public record Video
 
     public string CoverUrl { get; init; } = string.Empty;
 
-
     public string VideoUrl { get; init; } = string.Empty;
 
     public int Duration { get; init; }
@@ -38,9 +37,9 @@ public record Video
 
     public int LikeCount { get; init; }
 
-    public DateTime CreatedAt { get; init; } = DateTime.Now; // todo
+    public DateTime CreatedAt { get; init; } = DateTime.UtcNow;
 
-    public DateTime UpdatedAt { get; init; } = DateTime.Now; // todo
+    public DateTime UpdatedAt { get; init; } = DateTime.UtcNow;
 
     public short Processed { get; init; } = 1;
 }
@@ -55,7 +54,7 @@ public interface IVideoRepository
     Task<Video> Save(Video video);
 }
 
-public class VideoRepository(MySqlDataSource dataSource) : IVideoRepository
+public class VideoRepository(NpgsqlDataSource dataSource) : IVideoRepository
 {
     const string columns = "id, user_id, title, des, cover_url, video_url, duration, view_count, like_count, created_at, updated_at, processed";
 
@@ -67,12 +66,9 @@ public async Task<Video> FindById(long id)
             new { id });
     }
 
-    /// <summary>
-    /// Find all the videos by the ids.
-    /// </summary>
+    /// <summary> Find all the videos by the ids. </summary>
     /// <param name="ids"> The ids of the videos. </param>
     /// <returns> The list of videos. </returns>
-    [DapperAot(false)]
     public async Task<IReadOnlyList<Video>> FindAllByIds(IReadOnlyList<long> ids)
     {
         if (ids.Count == 0)
@@ -80,41 +76,13 @@ public async Task<IReadOnlyList<Video>> FindAllByIds(IReadOnlyList<long> ids)
             return [];
         }
         await using var connection = await dataSource.OpenConnectionAsync();
-        var inClause = new InClause<long>(ids);
-
-        var query = $"SELECT {columns} FROM videos WHERE id in {inClause.Condition}";
-        var command = connection.CreateCommand();
-        command.CommandText = query;
-        inClause.BindParam(command);
-        var result = await command.ExecuteReaderAsync();
-        var videos = new List<Video>();
-        while (await result.ReadAsync())
-        {
-            videos.Add(new Video
-            {
-                Id = result.GetInt64(0),
-                UserId = result.GetInt64(1),
-                Title = result.GetString(2),
-                Des = result.GetString(3),
-                CoverUrl = result.GetString(4),
-                VideoUrl = result.GetString(5),
-                Duration = result.GetInt32(6),
-                ViewCount = result.GetInt32(7),
-                LikeCount = result.GetInt32(8),
-                CreatedAt = result.GetDateTime(9),
-                UpdatedAt = result.GetDateTime(10),
-                Processed = result.GetInt16(11)
-            });
-        }
-        // reorder the videos by the ids
-        var mapOrder = ids.Select((id, index) => (id, index)).ToDictionary(p => p.id, p => p.index);
-        videos.Sort((a, b) => mapOrder[a.Id].CompareTo(mapOrder[b.Id]));
-        return videos;
+        var videos = await connection.QueryAsync<Video>(
+            $"SELECT {columns} FROM videos WHERE id = ANY(@ids) ORDER BY array_position(@ids, id)",
+            new { ids });
+        return videos.ToList();
     }
 
-    /// <summary>
-    /// Find the videos by the user id.
-    /// </summary>
+    /// <summary>  Find the videos by the user id. </summary>
     /// <param name="userId"> The user id. </param>
     /// <param name="page"> The page number. </param>
     /// <param name="size"> The size of the page. </param>
@@ -123,26 +91,20 @@ public async Task<IReadOnlyList<Video>> FindByUserId(long userId, long page, int
     {
         await using var connection = await dataSource.OpenConnectionAsync();
         var videos = await connection.QueryAsync<Video>(
-            $"SELECT {columns} FROM videos FORCE INDEX(user_created) " +
-            "WHERE processed = 1 AND  user_id = @userId AND id < @page ORDER BY id DESC LIMIT @size",
+            $"SELECT {columns} FROM videos WHERE processed = 1 AND user_id = @userId AND id < @page ORDER BY id DESC LIMIT @size",
             new { userId, page, size });
         return videos.ToList();
     }
 
-    /// <summary>  Find the recent videos. </summary>
-    /// <param name="page">
-    /// The page number.
-    /// </param>
-    /// <param name="size">
-    /// The size of the page.
-    /// </param>
+    /// <summary> Find the recent videos. </summary>
+    /// <param name="page"> The page number. </param>
+    /// <param name="size"> The size of the page. </param>
     /// <returns> The list of videos. </returns>
     public async Task<IReadOnlyList<Video>> FindRecent(long page, int size)
     {
         await using var connection = await dataSource.OpenConnectionAsync();
         var videos = await connection.QueryAsync<Video>(
-            $"SELECT {columns} FROM videos FORCE INDEX (processed) " +
-            "WHERE processed = 1 AND id < @page ORDER BY id DESC LIMIT @size",
+            $"SELECT {columns} FROM videos WHERE processed = 1 AND id < @page ORDER BY id DESC LIMIT @size",
             new { page, size });
         return videos.ToList();
     }
@@ -181,23 +143,12 @@ internal class RankedVideo
     public async Task<Video> Save(Video video)
     {
         await using var connection = await dataSource.OpenConnectionAsync();
-        var result = await connection.QuerySingleAsync<long>(
-            "INSERT INTO videos (user_id, title, des, cover_url, video_url, duration, view_count, like_count, created_at, updated_at, processed) VALUES (@UserId, @Title, @Des, @CoverUrl, @VideoUrl, @Duration, @ViewCount, @LikeCount, @CreatedAt, @UpdatedAt, @Processed); SELECT LAST_INSERT_ID();",
-            new
-            {
-                video.UserId,
-                video.Title,
-                video.Des,
-                video.CoverUrl,
-                video.VideoUrl,
-                video.Duration,
-                video.ViewCount,
-                video.LikeCount,
-                video.CreatedAt,
-                video.UpdatedAt,
-                video.Processed
-            });
-        return await FindById(result);
+        var result = await connection.QuerySingleAsync<Video>(
+            "INSERT INTO videos (user_id, title, des, cover_url, video_url, duration, view_count, like_count, created_at, updated_at, processed) VALUES (@UserId, @Title, @Des, @CoverUrl, @VideoUrl, @Duration, @ViewCount, @LikeCount, @CreatedAt, @UpdatedAt, @Processed) " +
+            $"returning {columns}",
+            video
+        );
+        return result;
     }
 }
 
@@ -206,29 +157,4 @@ public static class VideoRepositoryExtensions
 {
     public static IServiceCollection AddVideoRepository(this IServiceCollection services) =>
         services.AddSingleton<IVideoRepository, VideoRepository>();
-}
-
-/// <summary>  a SQL IN clause for a list of values of type T. </summary>
-/// <typeparam name="T">The type of the values in the IN clause.</typeparam>
-internal class InClause<T>(IEnumerable<T> values)
-{
-    /// <summary>  the parameters for the IN clause, each with a unique name and a value. </summary>
-    private IEnumerable<(string, T)> Parameters =>
-        values.Select((value, index) => ($"p{index}", value));
-
-    /// <summary>  the condition for the IN clause, which can be used in a SQL query. </summary>
-    public string Condition => $"({string.Join(", ", Parameters.Select(p => $"@{p.Item1}"))})";
-
-    /// <summary> Adds the parameters for the IN clause to the specified SQL command.</summary>
-    /// <param name="command">The SQL command to which the parameters will be added.</param>
-    /// <returns>The same SQL command, for chaining calls.</returns>
-    public MySqlCommand BindParam(MySqlCommand command)
-    {
-        foreach (var (key, value) in Parameters)
-        {
-            command.Parameters.AddWithValue(key, value);
-        }
-
-        return command;
-    }
 }
\ No newline at end of file
diff --git a/sharp/content/repository/Notification.cs b/sharp/content/repository/Notification.cs
index 2a22a5d8..53f2d1ca 100644
--- a/sharp/content/repository/Notification.cs
+++ b/sharp/content/repository/Notification.cs
@@ -13,7 +13,7 @@
  */
 
 using Dapper;
-using MySqlConnector;
+using Npgsql;
 
 namespace content.repository;
 
@@ -25,7 +25,7 @@ public record Message
     public string Content { get; init; } = string.Empty;
     public short Type { get; init; }
     public short Status { get; init; }
-    public DateTime CreatedAt { get; init; } = DateTime.Now;
+    public DateTime CreatedAt { get; init; } = DateTime.UtcNow;
 }
 
 public interface INotificationRepository
@@ -36,7 +36,7 @@ public interface INotificationRepository
     ValueTask UpdateStatus(long userId, long id, short status);
 }
 
-public class NotificationRepository(MySqlDataSource dataSource) : INotificationRepository
+public class NotificationRepository(NpgsqlDataSource dataSource) : INotificationRepository
 {
     public async ValueTask<IReadOnlyList<Message>> FindByReceiverId(long receiverId, long page, int size,
         bool unreadOnly = false)
@@ -62,15 +62,11 @@ public async ValueTask<IReadOnlyList<Message>> FindByReceiverId(long receiverId,
     public async ValueTask<Message> Save(Message notification)
     {
         await using var connection = await dataSource.OpenConnectionAsync();
-        var result = await connection.ExecuteAsync(
+        var id = await connection.QuerySingleAsync<long>(
             "INSERT INTO notifications (sender_id, receiver_id, content, type, status, created_at) " +
-            "VALUES (@SenderId, @ReceiverId, @Content, @Type, @Status, @CreatedAt)", notification);
-        if (result == 0)
-        {
-            throw new Exception("Insert notification failed");
-        }
-
-        notification.Id = await connection.QuerySingleAsync<long>("SELECT LAST_INSERT_ID()");
+            "VALUES (@SenderId, @ReceiverId, @Content, @Type, @Status, @CreatedAt) RETURNING id",
+            notification);
+        notification.Id = id;
         return notification;
     }