Information Schema

Information Schema provides an ANSI-standard way of viewing system metadata. TiDB also provides a number of custom INFORMATION_SCHEMA tables, in addition to the tables included for MySQL compatibility.

Many INFORMATION_SCHEMA tables have a corresponding SHOW command. The benefit of querying INFORMATION_SCHEMA is that it is possible to join between tables.

Tables for MySQL compatibility

Table Name	Description
`CHARACTER_SETS`	Provides a list of character sets the server supports.
`COLLATIONS`	Provides a list of collations that the server supports.
`COLLATION_CHARACTER_SET_APPLICABILITY`	Explains which collations apply to which character sets.
`COLUMNS`	Provides a list of columns for all tables.
`COLUMN_PRIVILEGES`	Not implemented by TiDB. Returns zero rows.
`COLUMN_STATISTICS`	Not implemented by TiDB. Returns zero rows.
`ENGINES`	Provides a list of supported storage engines.
`EVENTS`	Not implemented by TiDB. Returns zero rows.
`FILES`	Not implemented by TiDB. Returns zero rows.
`GLOBAL_STATUS`	Not implemented by TiDB. Returns zero rows.
`GLOBAL_VARIABLES`	Not implemented by TiDB. Returns zero rows.
`KEY_COLUMN_USAGE`	Describes the key constraints of the columns, such as the primary key constraint.
`OPTIMIZER_TRACE`	Not implemented by TiDB. Returns zero rows.
`PARAMETERS`	Not implemented by TiDB. Returns zero rows.
`PARTITIONS`	Provides a list of table partitions.
`PLUGINS`	Not implemented by TiDB. Returns zero rows.
`PROCESSLIST`	Provides similar information to the command `SHOW PROCESSLIST`.
`PROFILING`	Not implemented by TiDB. Returns zero rows.
`REFERENTIAL_CONSTRAINTS`	Provides information on `FOREIGN KEY` constraints.
`ROUTINES`	Not implemented by TiDB. Returns zero rows.
`SCHEMATA`	Provides similar information to `SHOW DATABASES`.
`SCHEMA_PRIVILEGES`	Not implemented by TiDB. Returns zero rows.
`SESSION_STATUS`	Not implemented by TiDB. Returns zero rows.
`SESSION_VARIABLES`	Provides similar functionality to the command `SHOW SESSION VARIABLES`
`STATISTICS`	Provides information on table indexes.
`TABLES`	Provides a list of tables that the current user has visibility of. Similar to `SHOW TABLES`.
`TABLESPACES`	Not implemented by TiDB. Returns zero rows.
`TABLE_CONSTRAINTS`	Provides information on primary keys, unique indexes and foreign keys.
`TABLE_PRIVILEGES`	Not implemented by TiDB. Returns zero rows.
`TRIGGERS`	Not implemented by TiDB. Returns zero rows.
`USER_PRIVILEGES`	Summarizes the privileges associated with the current user.
`VIEWS`	Provides a list of views that the current user has visibility of. Similar to running `SHOW FULL TABLES WHERE table_type = 'VIEW'`

Tables that are TiDB extensions

Table Name	Description
`ANALYZE_STATUS`	Provides information about tasks to collect statistics.
`CLIENT_ERRORS_SUMMARY_BY_HOST`	Provides a summary of errors and warnings generated by client requests and returned to clients.
`CLIENT_ERRORS_SUMMARY_BY_USER`	Provides a summary of errors and warnings generated by clients.
`CLIENT_ERRORS_SUMMARY_GLOBAL`	Provides a summary of errors and warnings generated by clients.
`CLUSTER_CONFIG`	Provides details about configuration settings for the entire TiDB cluster. This table is not applicable to TiDB Cloud.
`CLUSTER_DEADLOCKS`	Provides a cluster-level view of the `DEADLOCKS` table.
`CLUSTER_HARDWARE`	Provides details on the underlying physical hardware discovered on each TiDB component. This table is not applicable to TiDB Cloud.
`CLUSTER_INFO`	Provides details on the current cluster topology.
`CLUSTER_LOAD`	Provides current load information for TiDB servers in the cluster. This table is not applicable to TiDB Cloud.
`CLUSTER_LOG`	Provides a log for the entire TiDB cluster. This table is not applicable to TiDB Cloud.
`CLUSTER_PROCESSLIST`	Provides a cluster-level view of the `PROCESSLIST` table.
`CLUSTER_SLOW_QUERY`	Provides a cluster-level view of the `SLOW_QUERY` table.
`CLUSTER_STATEMENTS_SUMMARY`	Provides a cluster-level view of the `STATEMENTS_SUMMARY` table.
`CLUSTER_STATEMENTS_SUMMARY_HISTORY`	Provides a cluster-level view of the `STATEMENTS_SUMMARY_HISTORY` table.
`CLUSTER_TIDB_TRX`	Provides a cluster-level view of the `TIDB_TRX` table.
`CLUSTER_SYSTEMINFO`	Provides details about kernel parameter configuration for servers in the cluster. This table is not applicable to TiDB Cloud.
`DATA_LOCK_WAITS`	Provides the lock-waiting information on the TiKV server.
`DDL_JOBS`	Provides similar output to `ADMIN SHOW DDL JOBS`
`DEADLOCKS`	Provides the information of several deadlock errors that have recently occurred.
`INSPECTION_RESULT`	Triggers internal diagnostics checks. This table is not applicable to TiDB Cloud.
`INSPECTION_RULES`	A list of internal diagnostic checks performed. This table is not applicable to TiDB Cloud.
`INSPECTION_SUMMARY`	A summarized report of important monitoring metrics. This table is not applicable to TiDB Cloud.
`METRICS_SUMMARY`	A summary of metrics extracted from Prometheus. This table is not applicable to TiDB Cloud.
`METRICS_SUMMARY_BY_LABEL`	See `METRICS_SUMMARY` table.
`METRICS_TABLES`	Provides the PromQL definitions for tables in `METRICS_SCHEMA`. This table is not applicable to TiDB Cloud.
`PLACEMENT_POLICIES`	Provides information on all placement policies. This table is not applicable to TiDB Cloud.
`SEQUENCES`	The TiDB implementation of sequences is based on MariaDB.
`SLOW_QUERY`	Provides information on slow queries on the current TiDB server.
`STATEMENTS_SUMMARY`	Similar to performance_schema statement summary in MySQL.
`STATEMENTS_SUMMARY_HISTORY`	Similar to performance_schema statement summary history in MySQL.
`TABLE_STORAGE_STATS`	Provides details about table sizes in storage.
`TIDB_HOT_REGIONS`	Provides statistics about which regions are hot. This table is not applicable to TiDB Cloud.
`TIDB_HOT_REGIONS_HISTORY`	Provides history statistics about which Regions are hot.
`TIDB_INDEXES`	Provides index information about TiDB tables.
`TIDB_SERVERS_INFO`	Provides a list of TiDB servers (namely, tidb-server component)
`TIDB_TRX`	Provides the information of the transactions that are being executed on the TiDB node.
`TIFLASH_REPLICA`	Provides details about TiFlash replicas.
`TIKV_REGION_PEERS`	Provides details about where regions are stored.
`TIKV_REGION_STATUS`	Provides statistics about regions.
`TIKV_STORE_STATUS`	Provides basic information about TiKV servers.