| title | summary |
|---|---|
TIFLASH_SEGMENTS |
Learn the `TIFLASH_SEGMENTS` information_schema table. |
Warning:
Do not use this table in production environments, as the fields of the table are unstable, and subject to change in new releases of TiDB, without prior notice.
Note:
This table is not available on TiDB Serverless clusters.
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.1indicates that the table can be recycled.0indicates 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.