Skip to content

Latest commit

 

History

History
199 lines (182 loc) · 25.3 KB

information-schema.md

File metadata and controls

199 lines (182 loc) · 25.3 KB
title summary aliases
Information Schema
TiDB implements the ANSI-standard information_schema for viewing system metadata.
/docs/dev/system-tables/system-table-information-schema/
/docs/dev/reference/system-databases/information-schema/
/tidb/dev/system-table-information-schema/

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_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.
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'

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.
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.
CLUSTER_INFO Provides details on the current cluster topology.
CLUSTER_LOAD Provides current load information for TiDB servers in the cluster.
CLUSTER_LOG Provides a log for the entire TiDB cluster.
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.
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.
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.
INSPECTION_RULES A list of internal diagnostic checks performed.
INSPECTION_SUMMARY A summarized report of important monitoring metrics.
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.
METRICS_SUMMARY_BY_LABEL See METRICS_SUMMARY table.
METRICS_TABLES Provides the PromQL definitions for tables in METRICS_SCHEMA.
PLACEMENT_POLICIES Provides information on all placement policies.
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.
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.
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_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.
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.
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.
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.