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Version: Nightly

REGION_STATISTICS

The REGION_STATISTICS table provides detailed information about a region's statistics, including the total number of rows, disk size, and more. These statistics are approximate values.

USE INFORMATION_SCHEMA;
DESC REGION_STATISTICS;

The output is as follows:

+--------------------------+--------+------+------+---------+---------------+
| Column                   | Type   | Key  | Null | Default | Semantic Type |
+--------------------------+--------+------+------+---------+---------------+
| region_id                | UInt64 |      | NO   |         | FIELD         |
| table_id                 | UInt32 |      | NO   |         | FIELD         |
| region_number            | UInt32 |      | NO   |         | FIELD         |
| region_rows              | UInt64 |      | YES  |         | FIELD         |
| written_bytes_since_open | UInt64 |      | YES  |         | FIELD         |
| disk_size                | UInt64 |      | YES  |         | FIELD         |
| memtable_size            | UInt64 |      | YES  |         | FIELD         |
| manifest_size            | UInt64 |      | YES  |         | FIELD         |
| sst_size                 | UInt64 |      | YES  |         | FIELD         |
| sst_num                  | UInt64 |      | YES  |         | FIELD         |
| index_size               | UInt64 |      | YES  |         | FIELD         |
| engine                   | String |      | YES  |         | FIELD         |
| region_role              | String |      | YES  |         | FIELD         |
+--------------------------+--------+------+------+---------+---------------+

Fields in the REGION_STATISTICS table are described as follows:

  • region_id: The ID of the Region.
  • table_id: The ID of the table.
  • region_number: The number of the region in the table.
  • region_rows: The number of rows in the region. It includes rows in SST files owned by this region and rows in memtables. Rows from SST files referenced from other regions are not counted.
  • written_bytes_since_open: The number of bytes written to the region since the region was opened.
  • disk_size: The total size of data files in the region, including data, index and metadata etc.
  • memtable_size: The region's total size of memtables.
  • manifest_size: The region's total size of manifest files.
  • sst_size: The region's total size of SST files owned by this region. SST files referenced from other regions are not counted.
  • sst_num: The region's total number of SST files owned by this region. SST files referenced from other regions are not counted.
  • index_size: The region's total size of index files owned by this region. SST index files referenced from other regions are not counted.
  • engine: The engine type of the region, mito or metric.
  • region_role: The region's role, Leader or Follower. Retrieve a table's region statistics information as follows:
SELECT r.* FROM REGION_STATISTICS r LEFT JOIN TABLES t on r.table_id = t.table_id \
WHERE t.table_name = 'system_metrics';

Output:

+---------------+----------+---------------+-------------+--------------------------+-----------+---------------+---------------+----------+---------+------------+--------+-------------+
| region_id     | table_id | region_number | region_rows | written_bytes_since_open | disk_size | memtable_size | manifest_size | sst_size | sst_num | index_size | engine | region_role |
+---------------+----------+---------------+-------------+--------------------------+-----------+---------------+---------------+----------+---------+------------+--------+-------------+
| 4398046511104 |     1024 |             0 |           8 |                        0 |      4922 |             0 |          1338 |     3249 |       1 |        335 | mito   | Leader      |
+---------------+----------+---------------+-------------+--------------------------+-----------+---------------+---------------+----------+---------+------------+--------+-------------+