You can use the SHOW PREDOWNSAMPLES syntax to query pre-downsampling rules configured for a table.
Applicable engines and versions
The SHOW PREDOWNSAMPLES syntax is applicable only to all versions of LindormTSDB.
Syntax
SHOW PREDOWNSAMPLES [ ON table_identifier ]Parameters
Parameter | Required | Description |
table_identifier | No | The name of the table for which the pre-downsampling rules you want to query are configured. Note If you do not specify this parameter, pre-downsampling rules configured for all tables are returned by default. |
Examples
Example 1: Query the pre-downsampling rules configured for all tables.
SHOW PREDOWNSAMPLES;The following result is returned:
+--------+----------+------------+-----+----------------------+ | table | interval | aggregator | ttl | update_time | +--------+----------+------------+-----+----------------------+ | sensor | 1h | sum, max | 90d | 2021-10-10T08:00:00Z | | sensor | 5m | sum, max | 30d | 2021-10-10T08:00:00Z | | test | 1m | sum, max | 30d | 2021-10-10T08:00:00Z | | test | 2h | sum, max | 30d | 2021-10-10T08:00:00Z | +--------+----------+------------+-----+----------------------+Example 2: Query the pre-downsampling rules configured for a table named sensor.
SHOW PREDOWNSAMPLES ON sensor;The following result is returned:
+--------+----------+------------+-----+----------------------+ | table | interval | aggregator | ttl | update_time | +--------+----------+------------+-----+----------------------+ | sensor | 1h | sum, max | 90d | 2021-10-10T08:00:00Z | | sensor | 5m | sum, max | 30d | 2021-10-10T08:00:00Z | +--------+----------+------------+-----+----------------------+