TIFLASH_TABLES
TIFLASH_TABLES 表提供了关于 TiFlash 中数据表的统计信息。
USE information_schema;
DESC tiflash_tables;
+-------------------------------------------+--------------+------+------+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------------------------------------------+--------------+------+------+---------+-------+
| TIDB_DATABASE | varchar(64) | YES | | NULL | |
| TIDB_TABLE | varchar(64) | YES | | NULL | |
| TABLE_ID | bigint | YES | | NULL | |
| IS_TOMBSTONE | bigint | YES | | NULL | |
| SEGMENT_COUNT | bigint | YES | | NULL | |
| TOTAL_ROWS | bigint | YES | | NULL | |
| TOTAL_SIZE | bigint | YES | | NULL | |
| TOTAL_DELETE_RANGES | bigint | YES | | NULL | |
| DELTA_RATE_ROWS | double | YES | | NULL | |
| DELTA_RATE_SEGMENTS | double | YES | | NULL | |
| DELTA_PLACED_RATE | double | YES | | NULL | |
| DELTA_CACHE_SIZE | bigint | YES | | NULL | |
| DELTA_CACHE_RATE | double | YES | | NULL | |
| DELTA_CACHE_WASTED_RATE | double | YES | | NULL | |
| DELTA_INDEX_SIZE | bigint | YES | | NULL | |
| AVG_SEGMENT_ROWS | double | YES | | NULL | |
| AVG_SEGMENT_SIZE | double | YES | | NULL | |
| DELTA_COUNT | bigint | YES | | NULL | |
| TOTAL_DELTA_ROWS | bigint | YES | | NULL | |
| TOTAL_DELTA_SIZE | bigint | YES | | NULL | |
| AVG_DELTA_ROWS | double | YES | | NULL | |
| AVG_DELTA_SIZE | double | YES | | NULL | |
| AVG_DELTA_DELETE_RANGES | double | YES | | NULL | |
| STABLE_COUNT | bigint | YES | | NULL | |
| TOTAL_STABLE_ROWS | bigint | YES | | NULL | |
| TOTAL_STABLE_SIZE | bigint | YES | | NULL | |
| TOTAL_STABLE_SIZE_ON_DISK | bigint | YES | | NULL | |
| AVG_STABLE_ROWS | double | YES | | NULL | |
| AVG_STABLE_SIZE | double | YES | | NULL | |
| TOTAL_PACK_COUNT_IN_DELTA | bigint | YES | | NULL | |
| MAX_PACK_COUNT_IN_DELTA | bigint | YES | | NULL | |
| AVG_PACK_COUNT_IN_DELTA | double | YES | | NULL | |
| AVG_PACK_ROWS_IN_DELTA | double | YES | | NULL | |
| AVG_PACK_SIZE_IN_DELTA | double | YES | | NULL | |
| TOTAL_PACK_COUNT_IN_STABLE | bigint | YES | | NULL | |
| AVG_PACK_COUNT_IN_STABLE | double | YES | | NULL | |
| AVG_PACK_ROWS_IN_STABLE | double | YES | | NULL | |
| AVG_PACK_SIZE_IN_STABLE | double | YES | | NULL | |
| STORAGE_STABLE_NUM_SNAPSHOTS | bigint | YES | | NULL | |
| STORAGE_STABLE_OLDEST_SNAPSHOT_LIFETIME | double | YES | | NULL | |
| STORAGE_STABLE_OLDEST_SNAPSHOT_THREAD_ID | bigint | YES | | NULL | |
| STORAGE_STABLE_OLDEST_SNAPSHOT_TRACING_ID | varchar(128) | YES | | NULL | |
| STORAGE_DELTA_NUM_SNAPSHOTS | bigint | YES | | NULL | |
| STORAGE_DELTA_OLDEST_SNAPSHOT_LIFETIME | double | YES | | NULL | |
| STORAGE_DELTA_OLDEST_SNAPSHOT_THREAD_ID | bigint | YES | | NULL | |
| STORAGE_DELTA_OLDEST_SNAPSHOT_TRACING_ID | varchar(128) | YES | | NULL | |
| STORAGE_META_NUM_SNAPSHOTS | bigint | YES | | NULL | |
| STORAGE_META_OLDEST_SNAPSHOT_LIFETIME | double | YES | | NULL | |
| STORAGE_META_OLDEST_SNAPSHOT_THREAD_ID | bigint | YES | | NULL | |
| STORAGE_META_OLDEST_SNAPSHOT_TRACING_ID | varchar(128) | YES | | NULL | |
| BACKGROUND_TASKS_LENGTH | bigint | YES | | NULL | |
| TIFLASH_INSTANCE | varchar(64) | YES | | NULL | |
+-------------------------------------------+--------------+------+------+---------+-------+
TIFLASH_TABLES 表中的字段说明如下：
TIDB_DATABASE：TiDB 中该表所属的数据库名称。TIDB_TABLE：TiDB 中的表名。TABLE_ID：表的内部 ID，在 TiDB 集群内唯一。IS_TOMBSTONE：表示该表是否可以被回收。1表示可以被回收，0表示表处于正常状态。SEGMENT_COUNT：表中的段（Segment）数量。Segment 是 TiFlash 的数据管理单元。TOTAL_ROWS：表中的总行数。TOTAL_SIZE：表的总大小（字节数）。TOTAL_DELETE_RANGES：表中 Delete Range 的总数。DELTA_RATE_ROWS：表在 Delta 层的总行数占该表总行数的比例。DELTA_RATE_SEGMENTS：表中包含非空 Delta 层的段占所有段的比例。DELTA_PLACED_RATE：表在 Delta 层已完成索引构建的行数占比。DELTA_CACHE_SIZE：表在 Delta 层缓存的大小（字节数）。DELTA_CACHE_RATE：表在 Delta 层缓存数据的占比。DELTA_CACHE_WASTED_RATE：表在 Delta 层无效缓存数据的占比。DELTA_INDEX_SIZE：Delta 层索引占用的内存大小（字节数）。AVG_SEGMENT_ROWS：表所有段的平均行数。AVG_SEGMENT_SIZE：表所有段的平均大小（字节数）。DELTA_COUNT：表中包含非空 Delta 层的段数量。TOTAL_DELTA_ROWS：Delta 层的总行数。TOTAL_DELTA_SIZE：Delta 层数据的总大小（字节数）。AVG_DELTA_ROWS：所有 Delta 层数据的平均行数。AVG_DELTA_SIZE：所有 Delta 层数据的平均大小（字节数）。AVG_DELTA_DELETE_RANGES：所有 Delta 层 Delete Range 操作的平均次数。STABLE_COUNT：表中包含非空 Stable 层的段数量。TOTAL_STABLE_ROWS：所有 Stable 层的总行数。TOTAL_STABLE_SIZE：所有 Stable 层数据的总大小（字节数）。TOTAL_STABLE_SIZE_ON_DISK：所有 Stable 层数据在磁盘上占用的空间（字节数）。AVG_STABLE_ROWS：所有 Stable 层数据的平均行数。AVG_STABLE_SIZE：所有 Stable 层数据的平均大小（字节数）。TOTAL_PACK_COUNT_IN_DELTA：所有 Delta 层中列文件（Column File）的总数。MAX_PACK_COUNT_IN_DELTA：单个 Delta 层中列文件的最大数量。AVG_PACK_COUNT_IN_DELTA：所有 Delta 层中列文件的平均数量。AVG_PACK_ROWS_IN_DELTA：所有 Delta 层中所有列文件的平均行数。AVG_PACK_SIZE_IN_DELTA：所有 Delta 层中所有列文件的平均数据大小（字节数）。TOTAL_PACK_COUNT_IN_STABLE：所有 Stable 层中 Pack 的总数。AVG_PACK_COUNT_IN_STABLE：所有 Stable 层中 Pack 的平均数量。AVG_PACK_ROWS_IN_STABLE：所有 Stable 层中所有 Pack 的平均行数。AVG_PACK_SIZE_IN_STABLE：Stable 层中所有 Pack 的平均数据大小（字节数）。STORAGE_STABLE_NUM_SNAPSHOTS：Stable 层的快照数量。STORAGE_STABLE_OLDEST_SNAPSHOT_LIFETIME：Stable 层最早快照的存活时长（秒）。STORAGE_STABLE_OLDEST_SNAPSHOT_THREAD_ID：Stable 层最早快照的线程 ID。STORAGE_STABLE_OLDEST_SNAPSHOT_TRACING_ID：Stable 层最早快照的追踪 ID。STORAGE_DELTA_NUM_SNAPSHOTS：Delta 层的快照数量。STORAGE_DELTA_OLDEST_SNAPSHOT_LIFETIME：Delta 层最早快照的存活时长（秒）。STORAGE_DELTA_OLDEST_SNAPSHOT_THREAD_ID：Delta 层最早快照的线程 ID。STORAGE_DELTA_OLDEST_SNAPSHOT_TRACING_ID：Delta 层最早快照的追踪 ID。STORAGE_META_NUM_SNAPSHOTS：元信息中的快照数量。STORAGE_META_OLDEST_SNAPSHOT_LIFETIME：元信息中最早快照的存活时长（秒）。STORAGE_META_OLDEST_SNAPSHOT_THREAD_ID：元信息中最早快照的线程 ID。STORAGE_META_OLDEST_SNAPSHOT_TRACING_ID：元信息中最早快照的追踪 ID。BACKGROUND_TASKS_LENGTH：后台任务队列的长度。TIFLASH_INSTANCE：TiFlash 实例的地址。