把每个用户的事件流切分成会话。
ts 升序排列。相邻两个事件的时间间隔超过 30 分钟时，后一个事件开始一个新会话；间隔恰好 30 分钟仍属于同一个会话。session_no 从 1 开始。start（会话内最早的 ts）、结束时间 end（最晚的 ts）、事件数 n_events。输入
events(event_id, user_id, ts, event_type, page)：输入不保证有序输出
列为 user_id, session_no, start, end, n_events，行顺序不限。
events web/events
| # | event_idint64 | user_idint64 | tsdatetime | event_typestring | pagestring |
|---|---|---|---|---|---|
| 1 | 1 | 53 | 2026-06-03 17:57:33 | login | /home |
| 2 | 2 | 53 | 2026-06-04 15:21:00 | visit | /home |
| 3 | 3 | 53 | 2026-06-04 15:22:00 | view | /product/303 |
| 4 | 4 | 53 | 2026-06-04 15:32:04 | add_to_cart | /cart |
| 5 | 5 | 56 | 2026-06-05 23:24:19 | login | /home |
| 6 | 6 | 56 | 2026-06-05 23:29:18 | view | /product/202 |
| 7 | 7 | 56 | 2026-06-05 23:36:15 | view | /product/202 |
| 8 | 8 | 56 | 2026-06-05 23:47:36 | add_to_cart | /cart |
| 9 | 9 | 56 | 2026-06-05 23:56:24 | checkout | /checkout |
| 10 | 10 | 56 | 2026-06-06 19:14:00 | visit | /home |
| 11 | 11 | 56 | 2026-06-06 19:22:53 | view | /product/303 |
| 12 | 12 | 56 | 2026-06-06 19:25:12 | view | /home |
| 13 | 13 | 56 | 2026-06-06 19:28:25 | add_to_cart | /cart |
| 14 | 14 | 29 | 2026-06-07 10:40:01 | login | /home |
| 15 | 15 | 29 | 2026-06-07 10:46:43 | view | /product/303 |
| 16 | 16 | 29 | 2026-06-07 11:04:46 | add_to_cart | /cart |
| 17 | 17 | 29 | 2026-06-07 11:09:25 | checkout | /checkout |
| 18 | 18 | 34 | 2026-06-07 12:57:49 | login | /home |
| 19 | 19 | 34 | 2026-06-07 13:03:57 | view | /product/202 |
| 20 | 20 | 34 | 2026-06-07 13:11:07 | view | /home |
| # | user_idInt64 | session_noDecimal(precision=38, scale=0) | startDatetime(time_unit='us', time_zone=None) | endDatetime(time_unit='us', time_zone=None) | n_eventsInt64 |
|---|---|---|---|---|---|
| 1 | 53 | 2.0 | 2026-06-04 15:21:00 | 2026-06-04 15:32:04 | 3 |
| 2 | 4 | 1.0 | 2026-09-04 08:12:49 | 2026-09-04 08:35:27 | 5 |
| 3 | 4 | 3.0 | 2026-09-13 05:05:48 | 2026-09-13 05:35:11 | 6 |
| 4 | 4 | 4.0 | 2026-09-13 06:14:48 | 2026-09-13 06:33:11 | 5 |
| 5 | 4 | 6.0 | 2026-09-19 06:25:41 | 2026-09-19 06:54:22 | 5 |
| 6 | 4 | 7.0 | 2026-09-26 03:30:56 | 2026-09-26 03:36:17 | 2 |
| 7 | 4 | 8.0 | 2026-10-07 13:24:04 | 2026-10-07 13:24:04 | 1 |
| 8 | 23 | 2.0 | 2026-07-16 12:27:00 | 2026-07-16 12:38:59 | 2 |
| 9 | 23 | 5.0 | 2026-07-28 11:31:55 | 2026-07-28 11:40:35 | 2 |
| 10 | 23 | 9.0 | 2026-09-13 19:34:58 | 2026-09-13 19:42:23 | 2 |
| 11 | 23 | 10.0 | 2026-09-13 20:43:04 | 2026-09-13 20:51:39 | 2 |
| 12 | 23 | 11.0 | 2026-10-14 14:20:06 | 2026-10-14 14:20:06 | 1 |
| 13 | 24 | 2.0 | 2026-09-10 04:18:04 | 2026-09-10 04:30:44 | 4 |
| 14 | 33 | 1.0 | 2026-09-05 13:07:12 | 2026-09-05 13:17:04 | 3 |
| 15 | 33 | 3.0 | 2026-10-14 08:32:38 | 2026-10-14 08:34:26 | 2 |
| 16 | 33 | 4.0 | 2026-10-14 10:40:38 | 2026-10-14 10:55:13 | 3 |
| 17 | 40 | 2.0 | 2026-08-20 09:12:00 | 2026-08-20 09:28:09 | 2 |
| 18 | 40 | 5.0 | 2026-08-29 18:49:27 | 2026-08-29 19:06:21 | 3 |
| 19 | 43 | 1.0 | 2026-06-24 11:18:24 | 2026-06-24 11:27:09 | 2 |
| 20 | 43 | 3.0 | 2026-09-25 09:18:31 | 2026-09-25 09:30:29 | 4 |
| 21 | 43 | 4.0 | 2026-09-25 10:55:31 | 2026-09-25 11:08:43 | 3 |
| 22 | 45 | 1.0 | 2026-07-01 01:15:17 | 2026-07-01 01:40:37 | 5 |
| 23 | 45 | 3.0 | 2026-07-13 15:51:08 | 2026-07-13 16:09:08 | 3 |
| 24 | 45 | 4.0 | 2026-07-13 18:47:08 | 2026-07-13 19:05:47 | 3 |
| 25 | 45 | 6.0 | 2026-08-21 06:33:46 | 2026-08-21 07:58:24 | 10 |
| 26 | 45 | 7.0 | 2026-08-27 11:26:47 | 2026-08-27 11:34:11 | 3 |
| 27 | 45 | 8.0 | 2026-09-07 02:21:23 | 2026-09-07 02:34:31 | 3 |
| 28 | 51 | 1.0 | 2026-09-22 19:06:38 | 2026-09-22 19:15:13 | 2 |
| 29 | 51 | 3.0 | 2026-09-27 01:07:36 | 2026-09-27 01:20:02 | 3 |
| 30 | 51 | 4.0 | 2026-09-29 09:04:00 | 2026-09-29 09:10:29 | 2 |
| 31 | 56 | 1.0 | 2026-06-05 23:24:19 | 2026-06-05 23:56:24 | 5 |
| 32 | 56 | 3.0 | 2026-07-20 16:46:30 | 2026-07-20 17:02:06 | 3 |
| 33 | 56 | 4.0 | 2026-07-25 14:06:10 | 2026-07-25 14:12:51 | 3 |
| 34 | 56 | 6.0 | 2026-08-27 22:20:47 | 2026-08-27 22:56:20 | 3 |
| 35 | 56 | 7.0 | 2026-08-28 00:11:47 | 2026-08-28 00:14:56 | 2 |
| 36 | 56 | 8.0 | 2026-10-11 22:46:33 | 2026-10-11 23:09:05 | 5 |
| 37 | 1 | 2.0 | 2026-06-25 15:59:00 | 2026-06-25 16:03:03 | 3 |
| 38 | 1 | 5.0 | 2026-08-07 06:00:59 | 2026-08-07 06:16:45 | 3 |
| 39 | 1 | 9.0 | 2026-09-20 11:02:43 | 2026-09-20 11:11:52 | 3 |
| 40 | 21 | 2.0 | 2026-09-15 03:53:03 | 2026-09-15 04:12:15 | 3 |
| 41 | 21 | 5.0 | 2026-09-17 11:08:00 | 2026-09-17 11:41:55 | 3 |
| 42 | 21 | 9.0 | 2026-09-28 01:27:07 | 2026-09-28 01:34:45 | 3 |
| 43 | 21 | 10.0 | 2026-09-29 18:44:00 | 2026-09-29 18:54:46 | 3 |
| 44 | 21 | 11.0 | 2026-09-30 17:42:00 | 2026-09-30 17:47:20 | 2 |
| 45 | 21 | 14.0 | 2026-10-10 18:05:06 | 2026-10-10 18:26:55 | 3 |
| 46 | 25 | 2.0 | 2026-09-15 13:45:00 | 2026-09-15 14:03:39 | 3 |
| 47 | 42 | 2.0 | 2026-07-08 23:05:58 | 2026-07-08 23:30:18 | 4 |
| 48 | 42 | 5.0 | 2026-08-23 22:22:28 | 2026-08-23 22:41:09 | 3 |
| 49 | 5 | 2.0 | 2026-07-24 19:42:00 | 2026-07-24 19:56:47 | 3 |
| 50 | 5 | 5.0 | 2026-09-19 08:47:25 | 2026-09-19 08:57:03 | 3 |