Note
This view was introduced in OceanBase Database V4.2.0.
Purpose
The oceanbase.CDB_OB_DATA_DICTIONARY_IN_LOG view displays the location range of data dictionaries in the system log stream so that Change Data Capture (CDC) can conveniently consume the data dictionaries.
Related parameters
dump_data_dictionary_to_log_interval
Columns
| Column | Type | Nullable? | Description |
|---|---|---|---|
| TENANT_ID | bigint(20) | NO | The ID of the tenant. Valid values:
|
| SNAPSHOT_SCN | bigint(20) unsigned | NO | The snapshot system change number (SCN) of the tenant when the data dictionary was generated. |
| REPORT_TIME | timestamp(6) | NO | The time when the data dictionary was reported to the internal table, in µs. |
| START_LSN | bigint(20) unsigned | NO | The log sequence number (LSN) of the first log when the data dictionary was persisted in the log stream with the ID 1 of the tenant. |
| END_LSN | bigint(20) unsigned | NO | The LSN of the last log when the data dictionary was persisted in the log stream with the ID 1 of the tenant. |
Sample query
Query the location range of data dictionaries of all user tenants in the system log stream from 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 | 1722408567371559602 | 2024-07-31 14:49:27.420098 | 9118467 | 9118467 |
| 1004 | 1722408697334096435 | 2024-07-31 14:51:37.373029 | 13706567 | 13706567 |
+-----------+---------------------+----------------------------+-----------+----------+
2 rows in set