| title | summary | aliases | |||
|---|---|---|---|---|---|
Information Schema |
TiDB implements the ANSI-standard information_schema for viewing system metadata. |
|
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 statement. The benefit of querying INFORMATION_SCHEMA is that it is possible to join between tables.
| Table name | Description |
|---|---|
CHARACTER_SETS |
Provides a list of character sets the server supports. |
CHECK_CONSTRAINTS |
Provides information about CHECK constraints on tables. |
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. |
KEYWORDS |
Provides a full list of keywords. |
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_ATTRIBUTES |
Summarizes information about user comments and user attributes. |
USER_PRIVILEGES |
Summarizes the privileges associated with the current user. |
VARIABLES_INFO |
Provides information about TiDB system variables. |
VIEWS |
Provides a list of views that the current user has visibility of. Similar to running SHOW FULL TABLES WHERE table_type = 'VIEW' |
| Table name | Description |
|---|---|
CHARACTER_SETS |
Provides a list of character sets the server supports. |
CHECK_CONSTRAINTS |
Provides information about CHECK constraints on tables. |
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_ATTRIBUTES |
Summarizes information about user comments and user attributes. |
USER_PRIVILEGES |
Summarizes the privileges associated with the current user. |
VARIABLES_INFO |
Provides information about TiDB system variables. |
VIEWS |
Provides a list of views that the current user has visibility of. Similar to running SHOW FULL TABLES WHERE table_type = 'VIEW' |
Note:
Some of the following tables are only supported on TiDB Self-Hosted and not supported on TiDB Cloud. To get a full list of unsupported tables on TiDB Cloud, see System tables.
| 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. This table is not available on TiDB Serverless clusters. |
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_MEMORY_USAGE |
Provides a cluster-level view of the MEMORY_USAGE table. |
CLUSTER_MEMORY_USAGE_OPS_HISTORY |
Provides a cluster-level view of the MEMORY_USAGE_OPS_HISTORY table. |
CLUSTER_PROCESSLIST |
Provides a cluster-level view of the PROCESSLIST table. |
CLUSTER_SLOW_QUERY |
Provides a cluster-level view of the SLOW_QUERY table. This table is not available on TiDB Serverless clusters. |
CLUSTER_STATEMENTS_SUMMARY |
Provides a cluster-level view of the STATEMENTS_SUMMARY table. This table is not available on TiDB Serverless clusters. |
CLUSTER_STATEMENTS_SUMMARY_HISTORY |
Provides a cluster-level view of the STATEMENTS_SUMMARY_HISTORY table. This table is not available on TiDB Serverless clusters. |
CLUSTER_TIDB_INDEX_USAGE |
Provides a cluster-level view of the TIDB_INDEX_USAGE 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. |
MEMORY_USAGE |
The memory usage of the current TiDB instance. |
MEMORY_USAGE_OPS_HISTORY |
The history of memory-related operations and the execution basis of the current TiDB instance. |
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. This table is not applicable to TiDB Cloud. |
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 available on TiDB Serverless clusters. |
SEQUENCES |
The TiDB implementation of sequences is based on MariaDB. |
SLOW_QUERY |
Provides information on slow queries on the current TiDB server. This table is not available on TiDB Serverless clusters. |
STATEMENTS_SUMMARY |
Similar to performance_schema statement summary in MySQL. This table is not available on TiDB Serverless clusters. |
STATEMENTS_SUMMARY_HISTORY |
Similar to performance_schema statement summary history in MySQL. This table is not available on TiDB Serverless clusters. |
TABLE_STORAGE_STATS |
Provides details about table sizes in storage. |
TIDB_HOT_REGIONS |
Provides statistics about which regions are hot. |
TIDB_HOT_REGIONS_HISTORY |
Provides history statistics about which Regions are hot. |
TIDB_INDEXES |
Provides index information about TiDB tables. |
TIDB_INDEX_USAGE |
Provides the information of the index usage statistics on the TiDB node. ｜ |
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. |
| 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. This table is not available on TiDB Serverless clusters. |
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_MEMORY_USAGE |
Provides a cluster-level view of the MEMORY_USAGE table. This table is not applicable to TiDB Cloud. |
CLUSTER_MEMORY_USAGE_OPS_HISTORY |
Provides a cluster-level view of the MEMORY_USAGE_OPS_HISTORY table. 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. This table is not available on TiDB Serverless clusters. |
CLUSTER_STATEMENTS_SUMMARY |
Provides a cluster-level view of the STATEMENTS_SUMMARY table. This table is not available on TiDB Serverless clusters. |
CLUSTER_STATEMENTS_SUMMARY_HISTORY |
Provides a cluster-level view of the STATEMENTS_SUMMARY_HISTORY table. This table is not available on TiDB Serverless clusters. |
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. |
MEMORY_USAGE |
The memory usage of the current TiDB instance. |
MEMORY_USAGE_OPS_HISTORY |
The history of memory-related operations and the execution basis of the current TiDB instance. |
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. This table is not applicable to TiDB Cloud. |
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 available on TiDB Serverless clusters. |
SEQUENCES |
The TiDB implementation of sequences is based on MariaDB. |
SLOW_QUERY |
Provides information on slow queries on the current TiDB server. This table is not available on TiDB Serverless clusters. |
STATEMENTS_SUMMARY |
Similar to performance_schema statement summary in MySQL. This table is not available on TiDB Serverless clusters. |
STATEMENTS_SUMMARY_HISTORY |
Similar to performance_schema statement summary history in MySQL. This table is not available on TiDB Serverless clusters. |
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_INDEX_USAGE |
Provides the information of the index usage statistics on the TiDB node. ｜ |
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. |