Note
This view is available starting with V4.2.0.
Purpose
This view records the location range of the data dictionary in the system log stream, which facilitates the consumption of the data dictionary by Change Data Capture (CDC).
Columns
Column |
Type |
Nullable |
Description |
|---|---|---|---|
| SNAPSHOT_SCN | bigint(20) unsigned | NO | The SNAPSHOT SCN of the corresponding tenant when the data dictionary was generated. |
| REPORT_TIME | timestamp(6) | YES | The time when the data dictionary was generated and reported to the internal table. (The unit is microseconds.) |
| START_LSN | bigint(20) unsigned | NO | The LSN of the first log in the tenant's primary log stream where the data dictionary was persisted. |
| END_LSN | bigint(20) unsigned | NO | The LSN of the last log in the tenant's primary log stream where the data dictionary was persisted. |
Sample query
Query the location range of the data dictionaries of all user tenants in the system log stream in the sys tenant.
obclient [oceanbase]> SELECT * FROM oceanbase.CDB_OB_DATA_DICTIONARY_IN_LOG;
The query result is as follows:
+-----------+---------------------+----------------------------+-----------+-----------+
| TENANT_ID | SNAPSHOT_SCN | REPORT_TIME | START_LSN | END_LSN |
+-----------+---------------------+----------------------------+-----------+-----------+
| 1002 | 1723084121964378000 | 2024-08-08 10:28:42.014127 | 10713062 | 10713062 |
| 1002 | 1723170522400303000 | 2024-08-09 10:28:42.439283 | 139661239 | 139661239 |
| 1004 | 1723084155932969000 | 2024-08-08 10:29:15.983581 | 16136726 | 16136726 |
| 1004 | 1723170556335749000 | 2024-08-09 10:29:16.366229 | 148555952 | 148555952 |
+-----------+---------------------+----------------------------+-----------+-----------+
4 rows in set