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.