System Tables

Databend provides a set of system tables that contain metadata about your Databend 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 Databend environment.

Available System Tables

Database & Table Metadata

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.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.

Query & Performance

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.

Functions & Settings

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.
system.configs	Contains configuration information for the Databend deployment.

System Information

Table	Description
system.build_options	Contains information about build options used to compile Databend.
system.clusters	Contains information about clusters in the system.
system.contributors	Lists contributors to the Databend project.
system.credits	Contains information about third-party libraries used in Databend.
system.caches	Provides information about system caches.

Utility Tables

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.

Information Schema

Table	Description
information_schema.tables	ANSI SQL standard metadata view for tables.