TIFLASH_SEGMENTS

The TIFLASH_SEGMENTS table provides statistical information about data tables in TiFlash.

USE information_schema;
DESC tiflash_segments;

+-------------------------------+-------------+------+------+---------+-------+
| Field                         | Type        | Null | Key  | Default | Extra |
+-------------------------------+-------------+------+------+---------+-------+
| DATABASE                      | varchar(64) | YES  |      | NULL    |       |
| TABLE                         | varchar(64) | YES  |      | NULL    |       |
| TIDB_DATABASE                 | varchar(64) | YES  |      | NULL    |       |
| TIDB_TABLE                    | varchar(64) | YES  |      | NULL    |       |
| TABLE_ID                      | bigint(64)  | YES  |      | NULL    |       |
| IS_TOMBSTONE                  | bigint(64)  | YES  |      | NULL    |       |
| SEGMENT_ID                    | bigint(64)  | YES  |      | NULL    |       |
| RANGE                         | varchar(64) | YES  |      | NULL    |       |
| EPOCH                         | bigint(64)  | YES  |      | NULL    |       |
| ROWS                          | bigint(64)  | YES  |      | NULL    |       |
| SIZE                          | bigint(64)  | YES  |      | NULL    |       |
| DELTA_RATE                    | double      | YES  |      | NULL    |       |
| DELTA_MEMTABLE_ROWS           | bigint(64)  | YES  |      | NULL    |       |
| DELTA_MEMTABLE_SIZE           | bigint(64)  | YES  |      | NULL    |       |
| DELTA_MEMTABLE_COLUMN_FILES   | bigint(64)  | YES  |      | NULL    |       |
| DELTA_MEMTABLE_DELETE_RANGES  | bigint(64)  | YES  |      | NULL    |       |
| DELTA_PERSISTED_PAGE_ID       | bigint(64)  | YES  |      | NULL    |       |
| DELTA_PERSISTED_ROWS          | bigint(64)  | YES  |      | NULL    |       |
| DELTA_PERSISTED_SIZE          | bigint(64)  | YES  |      | NULL    |       |
| DELTA_PERSISTED_COLUMN_FILES  | bigint(64)  | YES  |      | NULL    |       |
| DELTA_PERSISTED_DELETE_RANGES | bigint(64)  | YES  |      | NULL    |       |
| DELTA_CACHE_SIZE              | bigint(64)  | YES  |      | NULL    |       |
| DELTA_INDEX_SIZE              | bigint(64)  | YES  |      | NULL    |       |
| STABLE_PAGE_ID                | bigint(64)  | YES  |      | NULL    |       |
| STABLE_ROWS                   | bigint(64)  | YES  |      | NULL    |       |
| STABLE_SIZE                   | bigint(64)  | YES  |      | NULL    |       |
| STABLE_DMFILES                | bigint(64)  | YES  |      | NULL    |       |
| STABLE_DMFILES_ID_0           | bigint(64)  | YES  |      | NULL    |       |
| STABLE_DMFILES_ROWS           | bigint(64)  | YES  |      | NULL    |       |
| STABLE_DMFILES_SIZE           | bigint(64)  | YES  |      | NULL    |       |
| STABLE_DMFILES_SIZE_ON_DISK   | bigint(64)  | YES  |      | NULL    |       |
| STABLE_DMFILES_PACKS          | bigint(64)  | YES  |      | NULL    |       |
| TIFLASH_INSTANCE              | varchar(64) | YES  |      | NULL    |       |
+-------------------------------+-------------+------+------+---------+-------+
33 rows in set (0.00 sec)

Fields in the TIFLASH_SEGMENTS table are described as follows:

• DATABASE: Database name in TiFlash. The segment belongs to a table in this database.
• TABLE: Table name in TiFlash. The segment belongs to this table.
• TIDB_DATABASE: Database name in TiDB. The segment belongs to a table in this database.
• TIDB_TABLE: Table name in TiDB. The segment belongs to this table.
• TABLE_ID: The internal ID of the table to which the segment belongs. This ID is unique within a TiDB cluster.
• IS_TOMBSTONE: Indicates whether the table the segment belongs to can be recycled. 1 indicates that the table can be recycled. 0 indicates that the table is in a normal state.
• SEGMENT_ID: Segment ID, which is unique within a table.
• RANGE: The range of data that the segment contains.
• EPOCH: The updated version of the segment. The version number of each segment increases monotonically.
• ROWS: The total number of rows in the segment.
• SIZE: The total size of the segment data (in bytes).
• DELTA_RATE: The ratio of the total number of rows in the Delta layer to that in the segment.
• DELTA_MEMTABLE_ROWS: The total number of cached rows in the Delta layer.
• DELTA_MEMTABLE_SIZE: The total size of the data cached in the Delta layer (in bytes).
• DELTA_MEMTABLE_COLUMN_FILES: The number of Column Files cached in the Delta layer.
• DELTA_MEMTABLE_DELETE_RANGES: The number of Delete Ranges cached in the Delta layer.
• DELTA_PERSISTED_PAGE_ID: The ID of the data stored on a disk in the Delta layer.
• DELTA_PERSISTED_ROWS: The total number of rows of persisted data in the Delta layer.
• DELTA_PERSISTED_SIZE: The total size of the persisted data in the Delta layer (in bytes).
• DELTA_PERSISTED_COLUMN_FILES: The number of persisted Column Files in the Delta layer.
• DELTA_PERSISTED_DELETE_RANGES: The number of persisted Delete Ranges in the Delta layer.
• DELTA_CACHE_SIZE: The size of the cache in the Delta layer (in bytes).
• DELTA_INDEX_SIZE: The size of the indexes in the Delta layer (in bytes).
• STABLE_PAGE_ID: The disk storage ID of the data in the Stable layer.
• STABLE_ROWS: The total number of rows in the Stable layer.
• STABLE_SIZE: The total size of the data in the Stable layer (in bytes).
• STABLE_DMFILES: The number of DMFiles in the Stable layer.
• STABLE_DMFILES_ID_0: The disk storage ID of the first DMFile in the Stable layer.
• STABLE_DMFILES_ROWS: The total number of rows in the DMFile in the Stable layer.
• STABLE_DMFILES_SIZE: The total size of the data in the DMFile in the Stable layer (in bytes).
• STABLE_DMFILES_SIZE_ON_DISK: The disk space occupied by the DMFile in the Stable layer (in bytes).
• STABLE_DMFILES_PACKS: The number of Packs in the DMFile in the Stable layer.
• TIFLASH_INSTANCE: The address of the TiFlash instance.