Important
You are viewing the documentation of an older version of the TiDB database (TiDB v5.4). It is recommended that you use the latest LTS version of the TiDB database.
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_RULES | Provides information on all objects that have explicit placement rules assigned. 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. |