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PURGE_LOG()

Function Description

PURGE_LOG() is used to delete logs recorded in the MatrixOne database system table. Returning 0 means that the deletion is successful; if the deletion fails, the error message will be returned.

Note

Currently, only the root user (i.e. the cluster administrator with MOADMIN permission) has permission to execute the PURGE_LOG() function for log deletion operations.

Function Syntax

> PURGE_LOG('sys_table_name', 'date')

Parameter definition

Parameters Description
'sys_table_name' There are only three system tables that can be deleted at present: metric, rawlog, and statement_info.
Note: 'sys_table_name' must be wrapped in quotes.
'date' Select a date to delete the logs generated before that date.
Note: 'date' must be wrapped in single quotes.

Note

MatrixOne has only three system log tables: metric, rawlog, and statement_info. For more information about these three tables, please refer to MatrixOne System Database and Tables.

Example

  • Example 1:
-- Delete the log of type statement_info before this day
mysql> select purge_log('statement_info', '2023-06-30') a;
+------+
| a |
+------+
| 0 |
+------+
1 row in set (0.01 sec)
  • Example 2:
-- Query the time and quantity of metric log collection
mysql> select date(collecttime), count(1) from system_metrics.metric group by date(collecttime);
+---------------------------------+
| date(collecttime) | count(1) |
+---------------------------------+
| 2023-07-07 | 20067 |
| 2023-07-06 | 30246 |
| 2023-07-05 | 27759 |
+---------------------------------+
3 rows in set (0.04 sec)

-- Delete the logs of rawlog, statement_info, and metric before this day.
mysql> select purge_log('rawlog, statement_info, metric', '2023-07-06');
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| purge_log(rawlog, statement_info, metric, 2023-07-06) |
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| 0 |
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1 row in set (0.33 sec)

-- Query again 2023-07-05, 2023-07-06 and 2023-07-07
mysql> select date(collecttime), count(1) from system_metrics.metric group by date(collecttime);
+---------------------------------+
| date(collecttime) | count(1) |
+---------------------------------+
| 2023-07-06 | 30246 |
| 2023-07-07 | 20121 |
+---------------------------------+
2 rows in set (0.01 sec)