TiDB Cloud Lake provides a set of system tables that contain metadata about your TiDB Cloud Lake deployment, databases, tables, queries, and system performance. These tables are read-only and are automatically updated by the system.
System tables are organized in the system schema and can be queried using standard SQL. They provide valuable information for monitoring, troubleshooting, and understanding your TiDB Cloud Lake environment.
| Table | Description |
|---|---|
| system.tables | Provides metadata information for all tables including properties, creation time, size, and more. |
| system.tables_with_history | Provides historical metadata information for tables, including dropped tables. |
| system.databases | Contains information about all databases in the system. |
| system.views | Contains information about all views in the system. |
| system.databases_with_history | Contains historical information about databases, including dropped databases. |
| system.columns | Provides information about columns in all tables. |
| system.indexes | Contains information about table indexes. |
| system.virtual_columns | Lists virtual columns available in the system. |
| Table | Description |
|---|---|
| system.query_log | Contains information about executed queries, including performance metrics. |
| system.metrics | Contains information about system metric events. |
| system.query_cache | Provides information about the query cache. |
| system.locks | Contains information about acquired locks in the system. |
| Table | Description |
|---|---|
| system.functions | Lists all available built-in functions. |
| system.table_functions | Lists all available table functions. |
| system.user_functions | Contains information about user-defined functions. |
| system.settings | Contains information about system settings. |
| Table | Description |
|---|---|
| system.build_options | Contains information about build options used to compile TiDB Cloud Lake. |
| system.clusters | Contains information about clusters in the system. |
| system.contributors | Lists contributors to the TiDB Cloud Lake project. |
| system.credits | Contains information about third-party libraries used in TiDB Cloud Lake. |
| system.caches | Provides information about system caches. |
| Table | Description |
|---|---|
| system.numbers | A table containing a single column with integers starting from 0, useful for generating test data. |
| system.streams | Contains information about streams in the system. |
| system.temp_tables | Contains information about temporary tables. |
| system.temp_files | Contains information about temporary files. |