Information Schema

为了和 MySQL 保持兼容，TiDB 支持很多 INFORMATION_SCHEMA 表，其中有不少表都支持相应的 SHOW 命令。查询 INFORMATION_SCHEMA 表也为表的连接操作提供了可能。

ANALYZE_STATUS Table

ANALYZE_STATUS 表提供正在执行的收集统计信息的任务以及有限条历史任务记录。

  1. mysql> select * from `ANALYZE_STATUS`
  2. +--------------+------------+----------------+-------------------+----------------+---------------------+----------+
  3. | TABLE_SCHEMA | TABLE_NAME | PARTITION_NAME | JOB_INFO          | PROCESSED_ROWS | START_TIME          | STATE    |
  4. +--------------+------------+----------------+-------------------+----------------+---------------------+----------+
  5. | test         | t          |                | analyze index idx | 2              | 2019-06-21 19:51:14 | finished |
  6. | test         | t          |                | analyze columns   | 2              | 2019-06-21 19:51:14 | finished |
  7. | test         | t1         | p0             | analyze columns   | 0              | 2019-06-21 19:51:15 | finished |
  8. | test         | t1         | p3             | analyze columns   | 0              | 2019-06-21 19:51:15 | finished |
  9. | test         | t1         | p1             | analyze columns   | 0              | 2019-06-21 19:51:15 | finished |
  10. | test         | t1         | p2             | analyze columns   | 1              | 2019-06-21 19:51:15 | finished |
  11. +--------------+------------+----------------+-------------------+----------------+---------------------+----------+
  12. 6 rows in set

CHARACTER_SETS Table

CHARACTER_SETS 表提供字符集相关的信息。TiDB 目前仅支持部分字符集。

  1. mysql> SELECT * FROM character_sets;
  2. +--------------------+----------------------+---------------+--------+
  3. | CHARACTER_SET_NAME | DEFAULT_COLLATE_NAME | DESCRIPTION   | MAXLEN |
  4. +--------------------+----------------------+---------------+--------+
  5. | utf8               | utf8_bin             | UTF-8 Unicode |      3 |
  6. | utf8mb4            | utf8mb4_bin          | UTF-8 Unicode |      4 |
  7. | ascii              | ascii_bin            | US ASCII      |      1 |
  8. | latin1             | latin1_bin           | Latin1        |      1 |
  9. | binary             | binary               | binary        |      1 |
  10. +--------------------+----------------------+---------------+--------+
  11. 5 rows in set (0.00 sec)

COLLATIONS Table

COLLATIONS 表提供了 CHARACTER_SETS 表中字符集对应的排序规则列表。TiDB 当前仅支持二进制排序规则，包含该表仅为兼容 MySQL。

  1. mysql> SELECT * FROM collations WHERE character_set_name='utf8mb4';
  2. +------------------------+--------------------+------+------------+-------------+---------+
  3. | COLLATION_NAME         | CHARACTER_SET_NAME | ID   | IS_DEFAULT | IS_COMPILED | SORTLEN |
  4. +------------------------+--------------------+------+------------+-------------+---------+
  5. | utf8mb4_general_ci     | utf8mb4            |   45 | Yes        | Yes         |       1 |
  6. | utf8mb4_bin            | utf8mb4            |   46 |            | Yes         |       1 |
  7. | utf8mb4_unicode_ci     | utf8mb4            |  224 |            | Yes         |       1 |
  8. | utf8mb4_icelandic_ci   | utf8mb4            |  225 |            | Yes         |       1 |
  9. | utf8mb4_latvian_ci     | utf8mb4            |  226 |            | Yes         |       1 |
  10. | utf8mb4_romanian_ci    | utf8mb4            |  227 |            | Yes         |       1 |
  11. | utf8mb4_slovenian_ci   | utf8mb4            |  228 |            | Yes         |       1 |
  12. | utf8mb4_polish_ci      | utf8mb4            |  229 |            | Yes         |       1 |
  13. | utf8mb4_estonian_ci    | utf8mb4            |  230 |            | Yes         |       1 |
  14. | utf8mb4_spanish_ci     | utf8mb4            |  231 |            | Yes         |       1 |
  15. | utf8mb4_swedish_ci     | utf8mb4            |  232 |            | Yes         |       1 |
  16. | utf8mb4_turkish_ci     | utf8mb4            |  233 |            | Yes         |       1 |
  17. | utf8mb4_czech_ci       | utf8mb4            |  234 |            | Yes         |       1 |
  18. | utf8mb4_danish_ci      | utf8mb4            |  235 |            | Yes         |       1 |
  19. | utf8mb4_lithuanian_ci  | utf8mb4            |  236 |            | Yes         |       1 |
  20. | utf8mb4_slovak_ci      | utf8mb4            |  237 |            | Yes         |       1 |
  21. | utf8mb4_spanish2_ci    | utf8mb4            |  238 |            | Yes         |       1 |
  22. | utf8mb4_roman_ci       | utf8mb4            |  239 |            | Yes         |       1 |
  23. | utf8mb4_persian_ci     | utf8mb4            |  240 |            | Yes         |       1 |
  24. | utf8mb4_esperanto_ci   | utf8mb4            |  241 |            | Yes         |       1 |
  25. | utf8mb4_hungarian_ci   | utf8mb4            |  242 |            | Yes         |       1 |
  26. | utf8mb4_sinhala_ci     | utf8mb4            |  243 |            | Yes         |       1 |
  27. | utf8mb4_german2_ci     | utf8mb4            |  244 |            | Yes         |       1 |
  28. | utf8mb4_croatian_ci    | utf8mb4            |  245 |            | Yes         |       1 |
  29. | utf8mb4_unicode_520_ci | utf8mb4            |  246 |            | Yes         |       1 |
  30. | utf8mb4_vietnamese_ci  | utf8mb4            |  247 |            | Yes         |       1 |
  31. +------------------------+--------------------+------+------------+-------------+---------+
  32. 26 rows in set (0.00 sec)

COLLATION_CHARACTER_SET_APPLICABILITY Table

COLLATION_CHARACTER_SET_APPLICABILITY 表将排序规则映射至适用的字符集名称。和 COLLATIONS 表一样，包含此表也是为了兼容 MySQL。

  1. mysql> SELECT * FROM collation_character_set_applicability WHERE character_set_name='utf8mb4';
  2. +------------------------+--------------------+
  3. | COLLATION_NAME         | CHARACTER_SET_NAME |
  4. +------------------------+--------------------+
  5. | utf8mb4_general_ci     | utf8mb4            |
  6. | utf8mb4_bin            | utf8mb4            |
  7. | utf8mb4_unicode_ci     | utf8mb4            |
  8. | utf8mb4_icelandic_ci   | utf8mb4            |
  9. | utf8mb4_latvian_ci     | utf8mb4            |
  10. | utf8mb4_romanian_ci    | utf8mb4            |
  11. | utf8mb4_slovenian_ci   | utf8mb4            |
  12. | utf8mb4_polish_ci      | utf8mb4            |
  13. | utf8mb4_estonian_ci    | utf8mb4            |
  14. | utf8mb4_spanish_ci     | utf8mb4            |
  15. | utf8mb4_swedish_ci     | utf8mb4            |
  16. | utf8mb4_turkish_ci     | utf8mb4            |
  17. | utf8mb4_czech_ci       | utf8mb4            |
  18. | utf8mb4_danish_ci      | utf8mb4            |
  19. | utf8mb4_lithuanian_ci  | utf8mb4            |
  20. | utf8mb4_slovak_ci      | utf8mb4            |
  21. | utf8mb4_spanish2_ci    | utf8mb4            |
  22. | utf8mb4_roman_ci       | utf8mb4            |
  23. | utf8mb4_persian_ci     | utf8mb4            |
  24. | utf8mb4_esperanto_ci   | utf8mb4            |
  25. | utf8mb4_hungarian_ci   | utf8mb4            |
  26. | utf8mb4_sinhala_ci     | utf8mb4            |
  27. | utf8mb4_german2_ci     | utf8mb4            |
  28. | utf8mb4_croatian_ci    | utf8mb4            |
  29. | utf8mb4_unicode_520_ci | utf8mb4            |
  30. | utf8mb4_vietnamese_ci  | utf8mb4            |
  31. +------------------------+--------------------+
  32. 26 rows in set (0.00 sec)

COLUMNS Table

COLUMNS 表提供了表的所有列的信息。

  1. mysql> CREATE TABLE test.t1 (a int);
  2. 1 row in set (0.01 sec)
  3. mysql> SELECT * FROM information_schema.columns WHERE table_schema='test' AND TABLE_NAME='t1'\G
  4. *************************** 1. row ***************************
  5.            TABLE_CATALOG: def
  6.             TABLE_SCHEMA: test
  7.               TABLE_NAME: t1
  8.              COLUMN_NAME: a
  9.         ORDINAL_POSITION: 1
  10.           COLUMN_DEFAULT: NULL
  11.              IS_NULLABLE: YES
  12.                DATA_TYPE: int
  13. CHARACTER_MAXIMUM_LENGTH: NULL
  14.   CHARACTER_OCTET_LENGTH: NULL
  15.        NUMERIC_PRECISION: 11
  16.            NUMERIC_SCALE: 0
  17.       DATETIME_PRECISION: NULL
  18.       CHARACTER_SET_NAME: NULL
  19.           COLLATION_NAME: NULL
  20.              COLUMN_TYPE: int(11)
  21.               COLUMN_KEY: 
  22.                    EXTRA: 
  23.               PRIVILEGES: select,insert,update,references
  24.           COLUMN_COMMENT: 
  25.    GENERATION_EXPRESSION: 
  26. 1 row in set (0.01 sec)

对应的 SHOW 语句如下：

  1. mysql> SHOW COLUMNS FROM t1 FROM test;
  2. +-------+---------+------+------+---------+-------+
  3. | Field | Type    | Null | Key  | Default | Extra |
  4. +-------+---------+------+------+---------+-------+
  5. | a     | int(11) | YES  |      | NULL    |       |
  6. +-------+---------+------+------+---------+-------+
  7. 1 row in set (0.00 sec)

ENGINES Table

ENGINES 表提供了关于存储引擎的信息。从和 MySQL 兼容性上考虑，TiDB 会一直将 InnoDB 描述为唯一支持的引擎。

  1. mysql> SELECT * FROM engines\G
  2. *************************** 1. row ***************************
  3.       ENGINE: InnoDB
  4.      SUPPORT: DEFAULT
  5.      COMMENT: Supports transactions, row-level locking, and foreign keys
  6. TRANSACTIONS: YES
  7.           XA: YES
  8.   SAVEPOINTS: YES
  9. 1 row in set (0.00 sec)

KEY_COLUMN_USAGE Table

KEY_COLUMN_USAGE 表描述了列的键约束，比如主键约束。

  1. mysql> SELECT * FROM key_column_usage WHERE table_schema='mysql' and table_name='user'\G
  2. *************************** 1. row ***************************
  3.            CONSTRAINT_CATALOG: def
  4.             CONSTRAINT_SCHEMA: mysql
  5.               CONSTRAINT_NAME: PRIMARY
  6.                 TABLE_CATALOG: def
  7.                  TABLE_SCHEMA: mysql
  8.                    TABLE_NAME: user
  9.                   COLUMN_NAME: Host
  10.              ORDINAL_POSITION: 1
  11. POSITION_IN_UNIQUE_CONSTRAINT: NULL
  12.       REFERENCED_TABLE_SCHEMA: NULL
  13.         REFERENCED_TABLE_NAME: NULL
  14.        REFERENCED_COLUMN_NAME: NULL
  15. *************************** 2. row ***************************
  16.            CONSTRAINT_CATALOG: def
  17.             CONSTRAINT_SCHEMA: mysql
  18.               CONSTRAINT_NAME: PRIMARY
  19.                 TABLE_CATALOG: def
  20.                  TABLE_SCHEMA: mysql
  21.                    TABLE_NAME: user
  22.                   COLUMN_NAME: User
  23.              ORDINAL_POSITION: 2
  24. POSITION_IN_UNIQUE_CONSTRAINT: NULL
  25.       REFERENCED_TABLE_SCHEMA: NULL
  26.         REFERENCED_TABLE_NAME: NULL
  27.        REFERENCED_COLUMN_NAME: NULL
  28. 2 rows in set (0.00 sec)

PROCESSLIST Table

PROCESSLIST 和 show processlist 的功能一样，都是查看当前正在处理的请求。

PROCESSLIST 表会比 show processlist 多一个 MEM 列，MEM 是指正在处理的请求已使用的内存，单位是 byte。

  1. +----+------+------+--------------------+---------+------+-------+---------------------------+-----+
  2. | ID | USER | HOST | DB                 | COMMAND | TIME | STATE | INFO                      | MEM |
  3. +----+------+------+--------------------+---------+------+-------+---------------------------+-----+
  4. | 1  | root | ::1  | INFORMATION_SCHEMA | Query   | 0    | 2     | select * from PROCESSLIST | 0   |
  5. +----+------+------+--------------------+---------+------+-------+---------------------------+-----+

SCHEMATA Table

SCHEMATA 表提供了关于数据库的信息。表中的数据与 SHOW DATABASES 语句的执行结果等价。

  1. mysql> SELECT * FROM schemata; 
  2. +--------------+--------------------+----------------------------+------------------------+----------+ 
  3. | CATALOG_NAME | SCHEMA_NAME        | DEFAULT_CHARACTER_SET_NAME | DEFAULT_COLLATION_NAME | SQL_PATH | 
  4. +--------------+--------------------+----------------------------+------------------------+----------+ 
  5. | def          | INFORMATION_SCHEMA | utf8mb4                    | utf8mb4_bin            | NULL     | 
  6. | def          | mynewdb            | utf8mb4                    | utf8mb4_bin            | NULL     |
  7. | def          | mysql              | utf8mb4                    | utf8mb4_bin            | NULL     | 
  8. | def          | PERFORMANCE_SCHEMA | utf8mb4                    | utf8mb4_bin            | NULL     | 
  9. | def          | test               | utf8mb4                    | utf8mb4_bin            | NULL     | 
  10. +--------------+--------------------+----------------------------+------------------------+----------+ 
  11. 5 rows in set (0.00 sec)

SESSION_VARIABLES Table

SESSION_VARIABLES 表提供了关于 session 变量的信息。表中的数据跟 SHOW SESSION VARIABLES 语句执行结果类似。

  1. mysql> SELECT * FROM session_variables LIMIT 10;
  2. +----------------------------------+----------------------+
  3. | VARIABLE_NAME                    | VARIABLE_VALUE       |
  4. +----------------------------------+----------------------+
  5. | max_write_lock_count             | 18446744073709551615 |
  6. | server_id_bits                   | 32                   |
  7. | net_read_timeout                 | 30                   |
  8. | innodb_online_alter_log_max_size | 134217728            |
  9. | innodb_optimize_fulltext_only    | OFF                  |
  10. | max_join_size                    | 18446744073709551615 |
  11. | innodb_read_io_threads           | 4                    |
  12. | session_track_gtids              | OFF                  |
  13. | have_ssl                         | DISABLED             |
  14. | max_binlog_cache_size            | 18446744073709547520 |
  15. +----------------------------------+----------------------+
  16. 10 rows in set (0.00 sec)

SLOW_QUERY Table

SLOW_QUERY 提供了慢查询相关的一些信息。表里面的内容是通过解析 TiDB 慢日志文件的数据而来的，表中列名和慢日志中的字段名是一一对应的关系。更多操作可以参考慢查询日志文档。

  1.  mysql>desc SLOW_QUERY;
  2. +---------------+---------------------+------+-----+---------+-------+
  3. | Field         | Type                | Null | Key | Default | Extra |
  4. +---------------+---------------------+------+-----+---------+-------+
  5. | Time          | timestamp unsigned  | YES  |     | <null>  |       |
  6. | Txn_start_ts  | bigint(20) unsigned | YES  |     | <null>  |       |
  7. | User          | varchar(64)         | YES  |     | <null>  |       |
  8. | Host          | varchar(64)         | YES  |     | <null>  |       |
  9. | Conn_ID       | bigint(20) unsigned | YES  |     | <null>  |       |
  10. | Query_time    | double unsigned     | YES  |     | <null>  |       |
  11. | Process_time  | double unsigned     | YES  |     | <null>  |       |
  12. | Wait_time     | double unsigned     | YES  |     | <null>  |       |
  13. | Backoff_time  | double unsigned     | YES  |     | <null>  |       |
  14. | Request_count | bigint(20) unsigned | YES  |     | <null>  |       |
  15. | Total_keys    | bigint(20) unsigned | YES  |     | <null>  |       |
  16. | Process_keys  | bigint(20) unsigned | YES  |     | <null>  |       |
  17. | DB            | varchar(64)         | YES  |     | <null>  |       |
  18. | Index_ids     | varchar(100)        | YES  |     | <null>  |       |
  19. | Is_internal   | tinyint(1) unsigned | YES  |     | <null>  |       |
  20. | Digest        | varchar(64)         | YES  |     | <null>  |       |
  21. | Stats         | varchar(512)        | YES  |     | <null>  |       |
  22. | Cop_proc_avg  | double unsigned     | YES  |     | <null>  |       |
  23. | Cop_proc_p90  | double unsigned     | YES  |     | <null>  |       |
  24. | Cop_proc_max  | double unsigned     | YES  |     | <null>  |       |
  25. | Cop_proc_addr | varchar(64)         | YES  |     | <null>  |       |
  26. | Cop_wait_avg  | double unsigned     | YES  |     | <null>  |       |
  27. | Cop_wait_p90  | double unsigned     | YES  |     | <null>  |       |
  28. | Cop_wait_max  | double unsigned     | YES  |     | <null>  |       |
  29. | Cop_wait_addr | varchar(64)         | YES  |     | <null>  |       |
  30. | Mem_max       | bigint(20) unsigned | YES  |     | <null>  |       |
  31. | Query         | varchar(4096)       | YES  |     | <null>  |       |
  32. +---------------+---------------------+------+-----+---------+-------+

STATISTICS Table

STATISTICS 表提供了关于表索引的信息。

  1. mysql> desc statistics;
  2. +---------------|---------------------|------|------|---------|-------+
  3. | Field         | Type                | Null | Key  | Default | Extra |
  4. +---------------|---------------------|------|------|---------|-------+
  5. | TABLE_CATALOG | varchar(512)        | YES  |      | NULL    |       |
  6. | TABLE_SCHEMA  | varchar(64)         | YES  |      | NULL    |       |
  7. | TABLE_NAME    | varchar(64)         | YES  |      | NULL    |       |
  8. | NON_UNIQUE    | varchar(1)          | YES  |      | NULL    |       |
  9. | INDEX_SCHEMA  | varchar(64)         | YES  |      | NULL    |       |
  10. | INDEX_NAME    | varchar(64)         | YES  |      | NULL    |       |
  11. | SEQ_IN_INDEX  | bigint(2) UNSIGNED  | YES  |      | NULL    |       |
  12. | COLUMN_NAME   | varchar(21)         | YES  |      | NULL    |       |
  13. | COLLATION     | varchar(1)          | YES  |      | NULL    |       |
  14. | CARDINALITY   | bigint(21) UNSIGNED | YES  |      | NULL    |       |
  15. | SUB_PART      | bigint(3) UNSIGNED  | YES  |      | NULL    |       |
  16. | PACKED        | varchar(10)         | YES  |      | NULL    |       |
  17. | NULLABLE      | varchar(3)          | YES  |      | NULL    |       |
  18. | INDEX_TYPE    | varchar(16)         | YES  |      | NULL    |       |
  19. | COMMENT       | varchar(16)         | YES  |      | NULL    |       |
  20. | INDEX_COMMENT | varchar(1024)       | YES  |      | NULL    |       |
  21. +---------------|---------------------|------|------|---------|-------+

下列语句是等价的：

  1. SELECT * FROM INFORMATION_SCHEMA.STATISTICS
  2.   WHERE table_name = 'tbl_name'
  3.   AND table_schema = 'db_name'
  5. SHOW INDEX
  6.   FROM tbl_name
  7.   FROM db_name

TABLES Table

TABLES 表提供了数据库里面关于表的信息。

  1. mysql> SELECT * FROM tables WHERE table_schema='mysql' AND table_name='user'\G
  2. *************************** 1. row ***************************
  3.   TABLE_CATALOG: def
  4.    TABLE_SCHEMA: mysql
  5.      TABLE_NAME: user
  6.      TABLE_TYPE: BASE TABLE
  7.          ENGINE: InnoDB
  8.         VERSION: 10
  9.      ROW_FORMAT: Compact
  10.      TABLE_ROWS: 0
  11.  AVG_ROW_LENGTH: 0
  12.     DATA_LENGTH: 0
  13. MAX_DATA_LENGTH: 0
  14.    INDEX_LENGTH: 0
  15.       DATA_FREE: 0
  16.  AUTO_INCREMENT: 0
  17.     CREATE_TIME: 2019-03-29 09:17:27
  18.     UPDATE_TIME: NULL
  19.      CHECK_TIME: NULL
  20. TABLE_COLLATION: utf8mb4_bin
  21.        CHECKSUM: NULL
  22.  CREATE_OPTIONS: 
  23.   TABLE_COMMENT: 
  24.   TIDB_TABLE_ID: 5
  25. 1 row in set (0.00 sec)

以下操作是等价的：

  1. SELECT table_name FROM INFORMATION_SCHEMA.TABLES
  2.   WHERE table_schema = 'db_name'
  3.   [AND table_name LIKE 'wild']
  5. SHOW TABLES
  6.   FROM db_name
  7.   [LIKE 'wild']

TABLE_CONSTRAINTS Table

TABLE_CONSTRAINTS 表记录了表的约束信息。

  1. mysql> SELECT * FROM table_constraints WHERE constraint_type='UNIQUE'\G
  2. *************************** 1. row ***************************
  3. CONSTRAINT_CATALOG: def
  4.  CONSTRAINT_SCHEMA: mysql
  5.    CONSTRAINT_NAME: name
  6.       TABLE_SCHEMA: mysql
  7.         TABLE_NAME: help_topic
  8.    CONSTRAINT_TYPE: UNIQUE
  9. *************************** 2. row ***************************
  10. CONSTRAINT_CATALOG: def
  11.  CONSTRAINT_SCHEMA: mysql
  12.    CONSTRAINT_NAME: tbl
  13.       TABLE_SCHEMA: mysql
  14.         TABLE_NAME: stats_meta
  15.    CONSTRAINT_TYPE: UNIQUE
  16. *************************** 3. row ***************************
  17. CONSTRAINT_CATALOG: def
  18.  CONSTRAINT_SCHEMA: mysql
  19.    CONSTRAINT_NAME: tbl
  20.       TABLE_SCHEMA: mysql
  21.         TABLE_NAME: stats_histograms
  22.    CONSTRAINT_TYPE: UNIQUE
  23. *************************** 4. row ***************************
  24. CONSTRAINT_CATALOG: def
  25.  CONSTRAINT_SCHEMA: mysql
  26.    CONSTRAINT_NAME: tbl
  27.       TABLE_SCHEMA: mysql
  28.         TABLE_NAME: stats_buckets
  29.    CONSTRAINT_TYPE: UNIQUE
  30. *************************** 5. row ***************************
  31. CONSTRAINT_CATALOG: def
  32.  CONSTRAINT_SCHEMA: mysql
  33.    CONSTRAINT_NAME: delete_range_index
  34.       TABLE_SCHEMA: mysql
  35.         TABLE_NAME: gc_delete_range
  36.    CONSTRAINT_TYPE: UNIQUE
  37. *************************** 6. row ***************************
  38. CONSTRAINT_CATALOG: def
  39.  CONSTRAINT_SCHEMA: mysql
  40.    CONSTRAINT_NAME: delete_range_done_index
  41.       TABLE_SCHEMA: mysql
  42.         TABLE_NAME: gc_delete_range_done
  43.    CONSTRAINT_TYPE: UNIQUE
  44. 6 rows in set (0.00 sec)

其中：

  • CONSTRAINT_TYPE 的取值可以是 UNIQUE，PRIMARY KEY，或者 FOREIGN KEY。
  • UNIQUE 和 PRIMARY KEY 信息与 SHOW INDEX 语句的执行结果类似。

TIDB_HOT_REGIONS Table

TIDB_HOT_REGIONS 表提供了关于热点 REGION 的相关信息。

  1. mysql> desc TIDB_HOT_REGIONS;
  2. +----------------+---------------------+------+-----+---------+-------+
  3. | Field          | Type                | Null | Key | Default | Extra |
  4. +----------------+---------------------+------+-----+---------+-------+
  5. | TABLE_ID       | bigint(21) unsigned | YES  |     | <null>  |       |
  6. | INDEX_ID       | bigint(21) unsigned | YES  |     | <null>  |       |
  7. | DB_NAME        | varchar(64)         | YES  |     | <null>  |       |
  8. | TABLE_NAME     | varchar(64)         | YES  |     | <null>  |       |
  9. | INDEX_NAME     | varchar(64)         | YES  |     | <null>  |       |
  10. | TYPE           | varchar(64)         | YES  |     | <null>  |       |
  11. | MAX_HOT_DEGREE | bigint(21) unsigned | YES  |     | <null>  |       |
  12. | REGION_COUNT   | bigint(21) unsigned | YES  |     | <null>  |       |
  13. | FLOW_BYTES     | bigint(21) unsigned | YES  |     | <null>  |       |
  14. +----------------+---------------------+------+-----+---------+-------+

TIDB_INDEXES Table

TIDB_INDEXES 记录了所有表中的 INDEX 信息。

  1. mysql>desc TIDB_INDEXES;
  2. +---------------+---------------------+------+-----+---------+-------+
  3. | Field         | Type                | Null | Key | Default | Extra |
  4. +---------------+---------------------+------+-----+---------+-------+
  5. | TABLE_SCHEMA  | varchar(64)         | YES  |     | <null>  |       |
  6. | TABLE_NAME    | varchar(64)         | YES  |     | <null>  |       |
  7. | NON_UNIQUE    | bigint(21) unsigned | YES  |     | <null>  |       |
  8. | KEY_NAME      | varchar(64)         | YES  |     | <null>  |       |
  9. | SEQ_IN_INDEX  | bigint(21) unsigned | YES  |     | <null>  |       |
  10. | COLUMN_NAME   | varchar(64)         | YES  |     | <null>  |       |
  11. | SUB_PART      | bigint(21) unsigned | YES  |     | <null>  |       |
  12. | INDEX_COMMENT | varchar(2048)       | YES  |     | <null>  |       |
  13. | INDEX_ID      | bigint(21) unsigned | YES  |     | <null>  |       |
  14. +---------------+---------------------+------+-----+---------+-------+

TIKV_REGION_PEERS Table

TIKV_REGION_PEERS 表提供了所有 REGION 的 peer 信息。

  1. mysql> desc TIKV_REGION_PEERS;
  2. +--------------+---------------------+------+-----+---------+-------+
  3. | Field        | Type                | Null | Key | Default | Extra |
  4. +--------------+---------------------+------+-----+---------+-------+
  5. | REGION_ID    | bigint(21) unsigned | YES  |     | <null>  |       |
  6. | PEER_ID      | bigint(21) unsigned | YES  |     | <null>  |       |
  7. | STORE_ID     | bigint(21) unsigned | YES  |     | <null>  |       |
  8. | IS_LEARNER   | tinyint(1) unsigned | YES  |     | <null>  |       |
  9. | IS_LEADER    | tinyint(1) unsigned | YES  |     | <null>  |       |
  10. | STATUS       | varchar(10)         | YES  |     | <null>  |       |
  11. | DOWN_SECONDS | bigint(21) unsigned | YES  |     | <null>  |       |
  12. +--------------+---------------------+------+-----+---------+-------+

TIKV_REGION_STATUS Table

TIKV_REGION_STATUS 表提供了所有 REGION 的状态信息。

  1. mysql> desc TIKV_REGION_STATUS;
  2. +------------------+---------------------+------+-----+---------+-------+
  3. | Field            | Type                | Null | Key | Default | Extra |
  4. +------------------+---------------------+------+-----+---------+-------+
  5. | REGION_ID        | bigint(21) unsigned | YES  |     | <null>  |       |
  6. | START_KEY        | text                | YES  |     | <null>  |       |
  7. | END_KEY          | text                | YES  |     | <null>  |       |
  8. | EPOCH_CONF_VER   | bigint(21) unsigned | YES  |     | <null>  |       |
  9. | EPOCH_VERSION    | bigint(21) unsigned | YES  |     | <null>  |       |
  10. | WRITTEN_BYTES    | bigint(21) unsigned | YES  |     | <null>  |       |
  11. | READ_BYTES       | bigint(21) unsigned | YES  |     | <null>  |       |
  12. | APPROXIMATE_SIZE | bigint(21) unsigned | YES  |     | <null>  |       |
  13. | APPROXIMATE_KEYS | bigint(21) unsigned | YES  |     | <null>  |       |
  14. +------------------+---------------------+------+-----+---------+-------+

TIKV_STORE_STATUS Table

TIKV_STORE_STATUS 表提供了所有 TiKV Store 的状态信息。

  1. mysql> desc TIKV_STORE_STATUS;
  2. +-------------------+---------------------+------+-----+---------+-------+
  3. | Field             | Type                | Null | Key | Default | Extra |
  4. +-------------------+---------------------+------+-----+---------+-------+
  5. | STORE_ID          | bigint(21) unsigned | YES  |     | <null>  |       |
  6. | ADDRESS           | varchar(64)         | YES  |     | <null>  |       |
  7. | STORE_STATE       | bigint(21) unsigned | YES  |     | <null>  |       |
  8. | STORE_STATE_NAME  | varchar(64)         | YES  |     | <null>  |       |
  9. | LABEL             | json unsigned       | YES  |     | <null>  |       |
  10. | VERSION           | varchar(64)         | YES  |     | <null>  |       |
  11. | CAPACITY          | varchar(64)         | YES  |     | <null>  |       |
  12. | AVAILABLE         | varchar(64)         | YES  |     | <null>  |       |
  13. | LEADER_COUNT      | bigint(21) unsigned | YES  |     | <null>  |       |
  14. | LEADER_WEIGHT     | bigint(21) unsigned | YES  |     | <null>  |       |
  15. | LEADER_SCORE      | bigint(21) unsigned | YES  |     | <null>  |       |
  16. | LEADER_SIZE       | bigint(21) unsigned | YES  |     | <null>  |       |
  17. | REGION_COUNT      | bigint(21) unsigned | YES  |     | <null>  |       |
  18. | REGION_WEIGHT     | bigint(21) unsigned | YES  |     | <null>  |       |
  19. | REGION_SCORE      | bigint(21) unsigned | YES  |     | <null>  |       |
  20. | REGION_SIZE       | bigint(21) unsigned | YES  |     | <null>  |       |
  21. | START_TS          | datetime unsigned   | YES  |     | <null>  |       |
  22. | LAST_HEARTBEAT_TS | datetime unsigned   | YES  |     | <null>  |       |
  23. | UPTIME            | varchar(64)         | YES  |     | <null>  |       |
  24. +-------------------+---------------------+------+-----+---------+-------+

USER_PRIVILEGES Table

USER_PRIVILEGES 表提供了关于全局权限的信息。该表的数据根据 mysql.user 系统表生成。

  1. mysql> desc USER_PRIVILEGES;
  2. +----------------|--------------|------|------|---------|-------+
  3. | Field          | Type         | Null | Key  | Default | Extra |
  4. +----------------|--------------|------|------|---------|-------+
  5. | GRANTEE        | varchar(81)  | YES  |      | NULL    |       |
  6. | TABLE_CATALOG  | varchar(512) | YES  |      | NULL    |       |
  7. | PRIVILEGE_TYPE | varchar(64)  | YES  |      | NULL    |       |
  8. | IS_GRANTABLE   | varchar(3)   | YES  |      | NULL    |       |
  9. +----------------|--------------|------|------|---------|-------+
  10. 4 rows in set (0.00 sec)

VIEWS Table

VIEWS 表提供了关于 SQL 视图的信息。

  1. mysql> create view test.v1 as select 1;
  2. Query OK, 0 rows affected (0.00 sec)
  3. mysql> select * from views\G
  4. *************************** 1. row ***************************
  5.        TABLE_CATALOG: def
  6.         TABLE_SCHEMA: test
  7.           TABLE_NAME: v1
  8.      VIEW_DEFINITION: select 1
  9.         CHECK_OPTION: CASCADED
  10.         IS_UPDATABLE: NO
  11.              DEFINER: root@127.0.0.1
  12.        SECURITY_TYPE: DEFINER
  13. CHARACTER_SET_CLIENT: utf8
  14. COLLATION_CONNECTION: utf8_general_ci
  15. 1 row in set (0.00 sec)

不支持的 Information Schema 表

TiDB 包含以下 INFORMATION_SCHEMA 表，但仅会返回空行：

  • COLUMN_PRIVILEGES
  • EVENTS
  • FILES
  • GLOBAL_STATUS
  • GLOBAL_VARIABLES
  • OPTIMIZER_TRACE
  • PARAMETERS
  • PARTITIONS
  • PLUGINS
  • PROFILING
  • REFERENTIAL_CONSTRAINTS
  • ROUTINES
  • SCHEMA_PRIVILEGES
  • SESSION_STATUS
  • TABLESPACES
  • TABLE_PRIVILEGES
  • TRIGGERS