SECURITY LABEL

SECURITY LABEL
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SECURITY LABEL — define or change a security label applied to an object

Synopsis

SECURITY LABEL [ FOR provider ] ON
{
  TABLE object_name |
  COLUMN table_name.column_name |
  AGGREGATE aggregate_name ( aggregate_signature ) |
  DATABASE object_name |
  DOMAIN object_name |
  EVENT TRIGGER object_name |
  FOREIGN TABLE object_name
  FUNCTION function_name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ] |
  LARGE OBJECT large_object_oid |
  MATERIALIZED VIEW object_name |
  [ PROCEDURAL ] LANGUAGE object_name |
  PROCEDURE procedure_name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ] |
  PUBLICATION object_name |
  ROLE object_name |
  ROUTINE routine_name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ] |
  SCHEMA object_name |
  SEQUENCE object_name |
  SUBSCRIPTION object_name |
  TABLESPACE object_name |
  TYPE object_name |
  VIEW object_name
} IS { string_literal | NULL }

where aggregate_signature is:

* |
[ argmode ] [ argname ] argtype [ , ... ] |
[ [ argmode ] [ argname ] argtype [ , ... ] ] ORDER BY [ argmode ] [ argname ] argtype [ , ... ]

Description

SECURITY LABEL applies a security label to a database object. An arbitrary number of security labels, one per label provider, can be associated with a given database object. Label providers are loadable modules which register themselves by using the function register_label_provider.

Note

register_label_provider is not an SQL function; it can only be called from C code loaded into the backend.

The label provider determines whether a given label is valid and whether it is permissible to assign that label to a given object. The meaning of a given label is likewise at the discretion of the label provider. PostgreSQL places no restrictions on whether or how a label provider must interpret security labels; it merely provides a mechanism for storing them. In practice, this facility is intended to allow integration with label-based mandatory access control (MAC) systems such as SELinux. Such systems make all access control decisions based on object labels, rather than traditional discretionary access control (DAC) concepts such as users and groups.

Parameters

object_name table_name.column_name aggregate_name function_name procedure_name routine_name: The name of the object to be labeled. Names of tables, aggregates, domains, foreign tables, functions, procedures, routines, sequences, types, and views can be schema-qualified.
provider: The name of the provider with which this label is to be associated. The named provider must be loaded and must consent to the proposed labeling operation. If exactly one provider is loaded, the provider name may be omitted for brevity.
argmode: The mode of a function, procedure, or aggregate argument: IN, OUT, INOUT, or VARIADIC. If omitted, the default is IN. Note that SECURITY LABEL does not actually pay any attention to OUT arguments, since only the input arguments are needed to determine the function's identity. So it is sufficient to list the IN, INOUT, and VARIADIC arguments.
argname: The name of a function, procedure, or aggregate argument. Note that SECURITY LABEL does not actually pay any attention to argument names, since only the argument data types are needed to determine the function's identity.
argtype: The data type of a function, procedure, or aggregate argument.
large_object_oid: The OID of the large object.
PROCEDURAL: This is a noise word.
string_literal: The new setting of the security label, written as a string literal.
NULL: Write NULL to drop the security label.

Examples

The following example shows how the security label of a table could be set or changed:

SECURITY LABEL FOR selinux ON TABLE mytable IS 'system_u:object_r:sepgsql_table_t:s0';

To remove the label:

SECURITY LABEL FOR selinux ON TABLE mytable IS NULL;

Compatibility

There is no SECURITY LABEL command in the SQL standard.