information_schema - CockroachDB

The information_schema contains information about your database’s tables, columns, indexes, and views. This information can be used for introspection and reflection.

Data exposed by `information_schema`

To perform introspection on objects, you can either read from the related information_schema table or use one of CockroachDB’s SHOW statements. information_schema tables are read-only.

Object	`information\_schema` Table	Corresponding `SHOW` Statement
Columns	`columns`
Constraints	`check\_constraints`, `key\_column\_usage`, `referential\_constraints`, `table\_constraints`
Databases	`schemata`
Indexes	`statistics`
Privileges	`schema\_privileges`, `table\_privileges`
Roles	`role\_table\_grants`
Sequences	`sequences`
Tables	`tables`
Views	`tables`, `views`

Tables in `information_schema`

The virtual schema information_schema contains virtual tables, also called “system views,” representing the database’s objects, each of which is detailed below. These differ from regular in that they do not show data created from the content of other tables. Instead, CockroachDB generates the data for virtual tables when they are accessed.

A query can specify a table name without a database name (e.g., SELECT * FROM information_schema.sequences). See for more information.

The virtual tables in information_schema contain useful comments with links to further documentation. To view these comments, use SHOW TABLES FROM information_schema WITH COMMENT:

administrable_role_authorizations

administrable_role_authorizations identifies all roles that the current user has the admin option for.

Column	Description
`grantee`	Name of the user to which this role membership was granted (always the current user).
`role\_name`	Name of a role.
`is\_grantable`	`YES` if the grantee has the admin option on the role; `NO` if not.

applicable_roles

applicable_roles identifies all roles whose privileges the current user can use. This implies there is a chain of role grants from the current user to the role in question. The current user itself is also an applicable role, but is not listed.

Column	Description
`grantee`	Name of the user to which this role membership was granted (always the current user).
`role\_name`	Name of a role.
`is\_grantable`	`YES` if the grantee has the admin option on the role; `NO` if not.

character_sets

character_sets identifies the character sets available in the current database.

Column	Description
`character\_set\_catalog`	Always `NULL` (unsupported by CockroachDB).
`character\_set\_schema`	Always `NULL` (unsupported by CockroachDB).
`character\_set\_name`	Name of the character set (i.e., the name of the database encoding). Always `UTF8`.
`character\_repertoire`	Character repertoire. `UCS` if the encoding is UTF8; the encoding name if not.
`form\_of\_use`	Character encoding form (i.e., the name of the database encoding). Always `UTF8`.
`default\_collate\_catalog`	Name of the database containing the default collation (if any collation is identified, always the current database).
`default\_collate\_schema`	Always `NULL` (unsupported by CockroachDB).
`default\_collate\_name`	Always `NULL` (unsupported by CockroachDB).

check_constraints

check_constraints contains information about the constraints applied to columns in a database.

Column	Description
`constraint\_catalog`	Name of the database containing the constraint.
`constraint\_schema`	Name of the schema containing the constraint.
`constraint\_name`	Name of the constraint.
`check\_clause`	Definition of the `CHECK` constraint.

collations

collations identifies the collations available in the current database.

Column	Description
`collation\_catalog`	Name of the database containing the collation (always the current database).
`collation\_schema`	Name of the schema containing the collation (always `pg\_catalog`).
`collation\_name`	Name of the collation.
`pad\_attribute`	Always `NO PAD` (`PAD SPACE` is not supported by CockroachDB).

collation_character_set_applicability

collation_character_set_applicability identifies which character set the available collations are applicable to.

Column	Description
`collation\_catalog`	Name of the database containing the collation (always the current database).
`collation\_schema`	Name of the schema containing the collation (always `pg\_catalog`).
`collation\_name`	Name of the collation.
`character\_set\_catalog`	Always `NULL` (unsupported by CockroachDB).
`character\_set\_schema`	Always `NULL` (unsupported by CockroachDB).
`character\_set\_name`	Name of the character set (always `UTF8`).

columns

columns contains information about the columns in each table.

Column	Description
`table\_catalog`	Name of the database containing the table.
`table\_schema`	Name of the schema containing the table.
`table\_name`	Name of the table.
`column\_name`	Name of the column.
`column\_comment`	Comment on the column.
`ordinal\_position`	Ordinal position of the column in the table (begins at 1).
`column\_default`	Default value for the column.
`is\_nullable`	`YES` if the column accepts `NULL` values; `NO` if it doesn’t (e.g., it has the ).
`data\_type`	of the column.
`character\_maximum\_length`	If `data\_type` is `STRING`, the maximum length in characters of a value; otherwise `NULL`.
`character\_octet\_length`	If `data\_type` is `STRING`, the maximum length in octets (bytes) of a value; otherwise `NULL`.
`numeric\_precision`	If `data\_type` is numeric, the declared or implicit precision (i.e., number of significant digits); otherwise `NULL`.
`numeric\_precision\_radix`	If `data\_type` identifies a numeric type, the base in which the values in the columns `numeric\_precision` and `numeric\_scale` are expressed (either `2` or `10`). For all other data types, column is `NULL`.
`numeric\_scale`	If `data\_type` is an exact numeric type, the scale (i.e., number of digits to the right of the decimal point); otherwise `NULL`.
`datetime\_precision`	The precision level of columns with data type , , or . For all other data types, this column is `NULL`.
`interval\_type`	If `data\_type` is , the specified fields (e.g., `YEAR TO MONTH`); otherwise `NULL`.
`interval\_precision`	If `data\_type` is , the declared or implicit precision (i.e., number of significant digits); otherwise `NULL`.
`character\_set\_catalog`	Always `NULL` (unsupported by CockroachDB).
`character\_set\_schema`	Always `NULL` (unsupported by CockroachDB).
`character\_set\_name`	Always `NULL` (unsupported by CockroachDB).
`collation\_catalog`	Name of the database containing the collation (always the current database); `NULL` if the default collation is used, or if `data\_type` is not collatable.
`collation\_schema`	Name of the schema containing the collation; `NULL` if the default collation is used, or if `data\_type` is not collatable.
`collation\_name`	Name of the collation; `NULL` if the default collation is used, or if `data\_type` is not collatable.
`domain\_catalog`	Always `NULL` (unsupported by CockroachDB).
`domain\_schema`	Always `NULL` (unsupported by CockroachDB).
`domain\_name`	Always `NULL` (unsupported by CockroachDB).
`udt\_catalog`	Name of the column data type’s database (always the current database).
`udt\_schema`	Name of the column data type’s schema.
`udt\_name`	Name of the column data type.
`scope\_catalog`	Always `NULL` (unsupported by CockroachDB).
`scope\_schema`	Always `NULL` (unsupported by CockroachDB).
`scope\_name`	Always `NULL` (unsupported by CockroachDB).
`maximum\_cardinality`	Always `NULL` (unsupported by CockroachDB).
`dtd\_identifier`	Always `NULL` (unsupported by CockroachDB).
`is\_self\_referencing`	Always `NULL` (unsupported by CockroachDB).
`is\_identity`	Whether or not the column is an identity column (always `NO`).
`identity\_generation`	Always `NULL` (unsupported by CockroachDB).
`identity\_start`	If the column is an identity column, then the start value of the internal sequence, else `NULL`.
`identity\_increment`	If the column is an identity column, then the increment of the internal sequence, else `NULL`.
`identity\_maximum`	If the column is an identity column, then the maximum value of the internal sequence, else `NULL`.
`identity\_minimum`	If the column is an identity column, then the minimum value of the internal sequence, else `NULL`.
`identity\_cycle`	If the column is an identity column, then `YES` if the internal sequence cycles or `NO` if it does not; otherwise `NULL`.
`is\_generated`	Whether or not the column is generated (i.e., a ). Possible values: `YES` or `NO`.
`generation\_expression`	The expression used for computing the column value in a computed column.
`is\_updatable`	Whether or not the column is able to be updated. Possible values: `YES` or `NO`.
`is\_hidden`	Whether or not the column is hidden. Possible values: `YES` or `NO`.
`crdb\_sql\_type`	of the column.

column_privileges

column_privileges identifies all privileges granted on columns to or by a currently enabled role. There is one row for each combination of grantor, grantee, and column (defined by table_catalog, table_schema, table_name, and column_name).

Column	Description
`grantor`	Name of the role that granted the privilege.
`grantee`	Name of the role that was granted the privilege.
`table\_catalog`	Name of the database containing the table that contains the column (always the current database).
`table\_schema`	Name of the schema containing the table that contains the column.
`table\_name`	Name of the table.
`column\_name`	Name of the column.
`privilege\_type`	Name of the .
`is\_grantable`	Always `NULL` (unsupported by CockroachDB).

column_udt_usage

column_udt_usage identifies all columns that use data types owned by a currently-enabled role.

Column	Description
`udt\_catalog`	Name of the database in which the column data type is defined (always the current database).
`udt\_schema`	Name of the schema in which the column data type is defined.
`udt\_name`	Name of the column data type.
`table\_catalog`	Name of the database containing the table (always the current database).
`table\_schema`	Name of the schema containing the table.
`table\_name`	Name of the table.
`column\_name`	Name of the column.

constraint_column_usage

constraint_column_usage identifies all columns in a database that are used by some .

Column	Description
`table\_catalog`	Name of the database that contains the table that contains the column that is used by some constraint.
`table\_schema`	Name of the schema that contains the table that contains the column that is used by some constraint.
`table\_name`	Name of the table that contains the column that is used by some constraint.
`column\_name`	Name of the column that is used by some constraint.
`constraint\_catalog`	Name of the database that contains the constraint.
`constraint\_schema`	Name of the schema that contains the constraint.
`constraint\_name`	Name of the constraint.

enabled_roles

The enabled_roles view identifies enabled roles for the current user. This includes both direct and indirect roles.

Column	Description
`role\_name`	Name of a role.

key_column_usage

key_column_usage identifies columns with , , or constraints.

Column	Description
`constraint\_catalog`	Name of the database containing the constraint.
`constraint\_schema`	Name of the schema containing the constraint.
`constraint\_name`	Name of the constraint.
`table\_catalog`	Name of the database containing the constrained table.
`table\_schema`	Name of the schema containing the constrained table.
`table\_name`	Name of the constrained table.
`column\_name`	Name of the constrained column.
`ordinal\_position`	Ordinal position of the column within the constraint (begins at 1).
`position\_in\_unique\_constraint`	For foreign key constraints, ordinal position of the referenced column within its uniqueness constraint (begins at 1).

referential_constraints

referential_constraints identifies all referential () constraints.

Column	Description
`constraint\_catalog`	Name of the database containing the constraint.
`constraint\_schema`	Name of the schema containing the constraint.
`constraint\_name`	Name of the constraint.
`unique\_constraint\_catalog`	Name of the database containing the `UNIQUE` or `PRIMARY KEY` constraint that the foreign key constraint references (always the current database).
`unique\_constraint\_schema`	Name of the schema containing the `UNIQUE` or `PRIMARY KEY` constraint that the foreign key constraint references.
`unique\_constraint\_name`	Name of the `UNIQUE` or `PRIMARY KEY` constraint.
`match\_option`	Match option of the foreign key constraint: `FULL`, `PARTIAL`, or `NONE`.
`update\_rule`	Update rule of the foreign key constraint: `CASCADE`, `SET NULL`, `SET DEFAULT`, `RESTRICT`, or `NO ACTION`.
`delete\_rule`	Delete rule of the foreign key constraint: `CASCADE`, `SET NULL`, `SET DEFAULT`, `RESTRICT`, or `NO ACTION`.
`table\_name`	Name of the table containing the constraint.
`referenced\_table\_name`	Name of the table containing the `UNIQUE` or `PRIMARY KEY` constraint that the foreign key constraint references.

role_table_grants

role_table_grants identifies which have been granted on tables or views where the grantor or grantee is a currently enabled role. This table is identical to table_privileges.

Column	Description
`grantor`	Name of the role that granted the privilege.
`grantee`	Name of the role that was granted the privilege.
`table\_catalog`	Name of the database containing the table.
`table\_schema`	Name of the schema containing the table.
`table\_name`	Name of the table.
`privilege\_type`	Name of the .
`is\_grantable`	`TRUE` if the grantee has the grant option on the object; `FALSE` if not.
`with\_hierarchy`	Always `NULL` (unsupported by CockroachDB).

schema_privileges

schema_privileges identifies which have been granted to each user at the database level.

Column	Description
`grantee`	Username of user with grant.
`table\_catalog`	Name of the database containing the constrained table.
`table\_schema`	Name of the schema containing the constrained table.
`privilege\_type`	Name of the .
`is\_grantable`	Always `NULL` (unsupported by CockroachDB).

schemata

schemata identifies the database’s schemas.

Column	Description
`table\_catalog`	Name of the database.
`table\_schema`	Name of the schema.
`default\_character\_set\_name`	Always `NULL` (unsupported by CockroachDB).
`sql\_path`	Always `NULL` (unsupported by CockroachDB).

sequences

sequences identifies defined in a database.

Column	Description
`sequence\_catalog`	Name of the database that contains the sequence.
`sequence\_schema`	Name of the schema that contains the sequence.
`sequence\_name`	Name of the sequence.
`data\_type`	The data type of the sequence.
`numeric\_precision`	The (declared or implicit) precision of the sequence `data\_type`.
`numeric\_precision\_radix`	The base of the values in which the columns `numeric\_precision` and `numeric\_scale` are expressed. The value is either `2` or `10`.
`numeric\_scale`	The (declared or implicit) scale of the sequence `data\_type`. The scale indicates the number of significant digits to the right of the decimal point. It can be expressed in decimal (base 10) or binary (base 2) terms, as specified in the column `numeric\_precision\_radix`.
`start\_value`	The first value of the sequence.
`minimum\_value`	The minimum value of the sequence.
`maximum\_value`	The maximum value of the sequence.
`increment`	The value by which the sequence is incremented. A negative number creates a descending sequence. A positive number creates an ascending sequence.
`cycle\_option`	Currently, all sequences are set to `NO CYCLE` and the sequence will not wrap.

session_variables

session_variables contains information about the for your session. session_variables contains a variable column and a value column. The value column corresponds to the output of the statement. For a list of the session variables, see . For a list of the session variables that have been updated from default values, see .

statistics

statistics identifies table .

Column	Description
`table\_catalog`	Name of the database that contains the constrained table.
`table\_schema`	Name of the schema that contains the constrained table.
`table\_name`	Name of the table.
`non\_unique`	`NO` if the index was created with the `UNIQUE` constraint; `YES` if the index was not created with `UNIQUE`.
`index\_schema`	Name of the schema that contains the index.
`index\_name`	Name of the index.
`seq\_in\_index`	Ordinal position of the column within the index (begins at 1).
`column\_name`	Name of the column being indexed.
`collation`	Always `NULL` (unsupported by CockroachDB).
`cardinality`	Always `NULL` (unsupported by CockroachDB).
`direction`	`ASC` (ascending) or `DESC` (descending) order.
`storing`	`YES` if column is ; `NO` if it’s indexed or implicit.
`implicit`	`YES` if column is implicit (i.e., it is not specified in the index and not stored); `NO` if it’s indexed or stored.

table_constraints

table_constraints identifies applied to tables.

Column	Description
`constraint\_catalog`	Name of the database containing the constraint.
`constraint\_schema`	Name of the schema containing the constraint.
`constraint\_name`	Name of the constraint.
`table\_catalog`	Name of the database containing the constrained table.
`table\_schema`	Name of the schema containing the constrained table.
`table\_name`	Name of the constrained table.
`constraint\_type`	Type of : `CHECK`, `FOREIGN KEY`, `PRIMARY KEY`, or `UNIQUE`. `NOT NULL` constraints appear as `CHECK` constraints in this column.
`is\_deferrable`	`YES` if the constraint can be deferred; `NO` if not.
`initially\_deferred`	`YES` if the constraint is deferrable and initially deferred; `NO` if not.

table_privileges

table_privileges identifies which have been granted to each user at the table level.

Column	Description
`grantor`	Always `NULL` (unsupported by CockroachDB).
`grantee`	Username of the user with grant.
`table\_catalog`	Name of the database that the grant applies to.
`table\_schema`	Name of the schema that the grant applies to.
`table\_name`	Name of the table that the grant applies to.
`privilege\_type`	Type of : `SELECT`, `INSERT`, `UPDATE`, `DELETE`, `TRUNCATE`, `REFERENCES`, or `TRIGGER`.
`is\_grantable`	`TRUE` if the grantee has the grant option on the object; `FALSE` if not.
`with\_hierarchy`	Always `NULL` (unsupported by CockroachDB).

tables

tables identifies tables and views in the database.

Column	Description
`table\_catalog`	Name of the database that contains the table.
`table\_schema`	Name of the schema that contains the table.
`table\_name`	Name of the table.
`table\_type`	Type of the table: `BASE TABLE` for a normal table, `VIEW` for a view, or `SYSTEM VIEW` for a view created by CockroachDB.
`version`	Version number of the table; versions begin at 1 and are incremented each time an `ALTER TABLE` statement is issued on the table. Note that this column is an experimental feature used for internal purposes inside CockroachDB and its definition is subject to change without notice.

type_privileges

type_privileges contains information about privileges on the user-defined types in the current database.

Column	Description
`grantee`	Username of user with privilege grant.
`type\_catalog`	Name of the database that contains the type (always the current database).
`type\_schema`	Name of the schema that contains the type.
`type\_name`	Name of the type.
`privilege\_type`	Type of .

user_privileges

user_privileges identifies global .

Column	Description
`grantee`	Username of user with grant.
`table\_catalog`	Name of the database that the privilege applies to.
`privilege\_type`	Type of .
`is\_grantable`	Always `NULL` (unsupported by CockroachDB).

views

views identifies in the database.

Column	Description
`table\_catalog`	Name of the database that contains the view.
`table\_schema`	Name of the schema that contains the view.
`table\_name`	Name of the view.
`view\_definition`	`AS` clause used to .
`check\_option`	Always `NULL` (unsupported by CockroachDB).
`is\_updatable`	Always `NULL` (unsupported by CockroachDB).
`is\_insertable\_into`	Always `NULL` (unsupported by CockroachDB).
`is\_trigger\_updatable`	Always `NULL` (unsupported by CockroachDB).
`is\_trigger\_deletable`	Always `NULL` (unsupported by CockroachDB).
`is\_trigger\_insertable\_into`	Always `NULL` (unsupported by CockroachDB).

Empty tables

For compatibility with third-party PostgreSQL and MySQL tooling, information_schema includes the following empty tables:

attributes
check_constraint_routine_usage
column_column_usage
column_domain_usage
column_options
column_statistics
columns_extensions
constraint_table_usage
data_type_privileges
domain_constraints
domain_udt_usage
domains
element_types
engines
events
files
foreign_data_wrapper_options
foreign_data_wrappers
foreign_server_options
foreign_servers
foreign_table_options
foreign_tables
information_schema_catalog_name
keywords
optimizer_trace
parameters
partitions
plugins
processlist
profiling
resource_groups
role_column_grants
role_routine_grants
role_udt_grants
role_usage_grants
routines
routine_privileges
schemata_extensions
sql_features
sql_implementation_info
sql_parts
sql_sizing
st_geometry_columns
st_spatial_reference_systems
st_units_of_measure
table_constraints_extensions
tables_extensions
tablespaces
tablespaces_extensions
transforms
triggered_update_columns
triggers
udt_privileges
usage_privileges
user_attributes
user_defined_types
user_mapping_options
user_mappings
view_column_usage
view_routine_usage
view_table_usage

Querying `information_schema` tables

You can run on the tables in information_schema.

The information_schema views typically represent objects that the current user has privilege to access. To ensure you can view all the objects in a database, access it as a user with .

Unless specified otherwise, queries to information_schema assume the .

For example, to retrieve all columns from the table_constraints table:

> SELECT * FROM movr.information_schema.table_constraints;

  constraint_catalog | constraint_schema |       constraint_name        | table_catalog | table_schema |         table_name         | constraint_type | is_deferrable | initially_deferred
---------------------+-------------------+------------------------------+---------------+--------------+----------------------------+-----------------+---------------+---------------------
  movr               | public            | users_pkey                   | movr          | public       | users                      | PRIMARY KEY     | NO            | NO
  movr               | public            | 3426283741_53_1_not_null     | movr          | public       | users                      | CHECK           | NO            | NO
  movr               | public            | 3426283741_53_2_not_null     | movr          | public       | users                      | CHECK           | NO            | NO
  movr               | public            | vehicles_pkey                | movr          | public       | vehicles                   | PRIMARY KEY     | NO            | NO
...
(25 rows)

And to retrieve specific columns from the table_constraints table:

> SELECT table_name, constraint_name FROM movr.information_schema.table_constraints;

          table_name         |       constraint_name
-----------------------------+-------------------------------
  users                      | primary
  users                      | 3426283741_53_1_not_null
  users                      | 3426283741_53_2_not_null
  vehicles                   | primary
...
(25 rows)

​Data exposed by information_schema

​Tables in information_schema

​administrable_role_authorizations

​applicable_roles

​character_sets

​check_constraints

​collations

​collation_character_set_applicability

​columns

​column_privileges

​column_udt_usage

​constraint_column_usage

​enabled_roles

​key_column_usage

​referential_constraints

​role_table_grants

​schema_privileges

​schemata

​sequences

​session_variables

​statistics

​table_constraints

​table_privileges

​tables

​type_privileges

​user_privileges

​views

​Empty tables

​Querying information_schema tables

​See also

Data exposed by `information_schema`

Tables in `information_schema`

administrable_role_authorizations

applicable_roles

character_sets

check_constraints

collations

collation_character_set_applicability

columns

column_privileges

column_udt_usage

constraint_column_usage

enabled_roles

key_column_usage

referential_constraints

role_table_grants

schema_privileges

schemata

sequences

session_variables

statistics

table_constraints

table_privileges

tables

type_privileges

user_privileges

views

Empty tables

Querying `information_schema` tables

See also