GRANT — define access privileges
GRANT { { SELECT | INSERT | UPDATE | DELETE | TRUNCATE | REFERENCES | TRIGGER }
    [, ...] | ALL [ PRIVILEGES ] }
    ON { [ TABLE ] table_name [, ...]
         | ALL TABLES IN SCHEMA schema_name [, ...] }
    TO role_specification [, ...] [ WITH GRANT OPTION ]
    [ GRANTED BY role_specification ]
GRANT { { SELECT | INSERT | UPDATE | REFERENCES } ( column_name [, ...] )
    [, ...] | ALL [ PRIVILEGES ] ( column_name [, ...] ) }
    ON [ TABLE ] table_name [, ...]
    TO role_specification [, ...] [ WITH GRANT OPTION ]
    [ GRANTED BY role_specification ]
GRANT { { USAGE | SELECT | UPDATE }
    [, ...] | ALL [ PRIVILEGES ] }
    ON { SEQUENCE sequence_name [, ...]
         | ALL SEQUENCES IN SCHEMA schema_name [, ...] }
    TO role_specification [, ...] [ WITH GRANT OPTION ]
    [ GRANTED BY role_specification ]
GRANT { { CREATE | CONNECT | TEMPORARY | TEMP } [, ...] | ALL [ PRIVILEGES ] }
    ON DATABASE database_name [, ...]
    TO role_specification [, ...] [ WITH GRANT OPTION ]
    [ GRANTED BY role_specification ]
GRANT { USAGE | ALL [ PRIVILEGES ] }
    ON DOMAIN domain_name [, ...]
    TO role_specification [, ...] [ WITH GRANT OPTION ]
    [ GRANTED BY role_specification ]
GRANT { USAGE | ALL [ PRIVILEGES ] }
    ON FOREIGN DATA WRAPPER fdw_name [, ...]
    TO role_specification [, ...] [ WITH GRANT OPTION ]
    [ GRANTED BY role_specification ]
GRANT { USAGE | ALL [ PRIVILEGES ] }
    ON FOREIGN SERVER server_name [, ...]
    TO role_specification [, ...] [ WITH GRANT OPTION ]
    [ GRANTED BY role_specification ]
GRANT { EXECUTE | ALL [ PRIVILEGES ] }
    ON { { FUNCTION | PROCEDURE | ROUTINE } routine_name [ ( [ [ argmode ] [ arg_name ] arg_type [, ...] ] ) ] [, ...]
         | ALL { FUNCTIONS | PROCEDURES | ROUTINES } IN SCHEMA schema_name [, ...] }
    TO role_specification [, ...] [ WITH GRANT OPTION ]
    [ GRANTED BY role_specification ]
GRANT { USAGE | ALL [ PRIVILEGES ] }
    ON LANGUAGE lang_name [, ...]
    TO role_specification [, ...] [ WITH GRANT OPTION ]
    [ GRANTED BY role_specification ]
GRANT { { SELECT | UPDATE } [, ...] | ALL [ PRIVILEGES ] }
    ON LARGE OBJECT loid [, ...]
    TO role_specification [, ...] [ WITH GRANT OPTION ]
    [ GRANTED BY role_specification ]
GRANT { { SET | ALTER SYSTEM } [, ... ] | ALL [ PRIVILEGES ] }
    ON PARAMETER configuration_parameter [, ...]
    TO role_specification [, ...] [ WITH GRANT OPTION ]
    [ GRANTED BY role_specification ]
GRANT { { CREATE | USAGE } [, ...] | ALL [ PRIVILEGES ] }
    ON SCHEMA schema_name [, ...]
    TO role_specification [, ...] [ WITH GRANT OPTION ]
    [ GRANTED BY role_specification ]
GRANT { CREATE | ALL [ PRIVILEGES ] }
    ON TABLESPACE tablespace_name [, ...]
    TO role_specification [, ...] [ WITH GRANT OPTION ]
    [ GRANTED BY role_specification ]
GRANT { USAGE | ALL [ PRIVILEGES ] }
    ON TYPE type_name [, ...]
    TO role_specification [, ...] [ WITH GRANT OPTION ]
    [ GRANTED BY role_specification ]
GRANT role_name [, ...] TO role_specification [, ...]
    [ WITH ADMIN OPTION ]
    [ GRANTED BY role_specification ]
where role_specification can be:
    [ GROUP ] role_name
  | PUBLIC
  | CURRENT_ROLE
  | CURRENT_USER
  | SESSION_USER
   The GRANT command has two basic variants: one
   that grants privileges on a database object (table, column, view,
   foreign table, sequence, database, foreign-data wrapper, foreign server,
   function, procedure, procedural language, large object, configuration
   parameter, schema, tablespace, or type), and one that grants
   membership in a role.  These variants are similar in many ways, but
   they are different enough to be described separately.
  
   This variant of the GRANT command gives specific
   privileges on a database object to
   one or more roles.  These privileges are added
   to those already granted, if any.
  
   The key word PUBLIC indicates that the
   privileges are to be granted to all roles, including those that might
   be created later.  PUBLIC can be thought of as an
   implicitly defined group that always includes all roles.
   Any particular role will have the sum
   of privileges granted directly to it, privileges granted to any role it
   is presently a member of, and privileges granted to
   PUBLIC.
  
   If WITH GRANT OPTION is specified, the recipient
   of the privilege can in turn grant it to others.  Without a grant
   option, the recipient cannot do that.  Grant options cannot be granted
   to PUBLIC.
  
   If GRANTED BY is specified, the specified grantor must
   be the current user.  This clause is currently present in this form only
   for SQL compatibility.
  
There is no need to grant privileges to the owner of an object (usually the user that created it), as the owner has all privileges by default. (The owner could, however, choose to revoke some of their own privileges for safety.)
The right to drop an object, or to alter its definition in any way, is not treated as a grantable privilege; it is inherent in the owner, and cannot be granted or revoked. (However, a similar effect can be obtained by granting or revoking membership in the role that owns the object; see below.) The owner implicitly has all grant options for the object, too.
The possible privileges are:
SELECTINSERTUPDATEDELETETRUNCATEREFERENCESTRIGGERCREATECONNECTTEMPORARYEXECUTEUSAGESETALTER SYSTEMSpecific types of privileges, as defined in Section 5.7.
TEMP
       Alternative spelling for TEMPORARY.
      
ALL PRIVILEGES
       Grant all of the privileges available for the object's type.
       The PRIVILEGES key word is optional in
       PostgreSQL, though it is required by
       strict SQL.
      
   The FUNCTION syntax works for plain functions,
   aggregate functions, and window functions, but not for procedures;
   use PROCEDURE for those.
   Alternatively, use ROUTINE to refer to a function,
   aggregate function, window function, or procedure regardless of its
   precise type.
  
   There is also an option to grant privileges on all objects of the same
   type within one or more schemas.  This functionality is currently supported
   only for tables, sequences, functions, and procedures.  ALL
   TABLES also affects views and foreign tables, just like the
   specific-object GRANT command.  ALL
   FUNCTIONS also affects aggregate and window functions, but not
   procedures, again just like the specific-object GRANT
   command.  Use ALL ROUTINES to include procedures.
  
   This variant of the GRANT command grants membership
   in a role to one or more other roles.  Membership in a role is significant
   because it conveys the privileges granted to a role to each of its
   members.
  
   If WITH ADMIN OPTION is specified, the member can
   in turn grant membership in the role to others, and revoke membership
   in the role as well.  Without the admin option, ordinary users cannot
   do that.  A role is not considered to hold WITH ADMIN
   OPTION on itself.  Database superusers can grant or revoke
   membership in any role to anyone.  Roles having
   CREATEROLE privilege can grant or revoke membership
   in any role that is not a superuser.
  
   If GRANTED BY is specified, the grant is recorded as
   having been done by the specified role.  Only database superusers may
   use this option, except when it names the same role executing the command.
  
   Unlike the case with privileges, membership in a role cannot be granted
   to PUBLIC.  Note also that this form of the command
   does not allow the noise word GROUP
   in role_specification.
  
    The REVOKE command is used
    to revoke access privileges.
   
    Since PostgreSQL 8.1, the concepts of users and
    groups have been unified into a single kind of entity called a role.
    It is therefore no longer necessary to use the keyword GROUP
    to identify whether a grantee is a user or a group.  GROUP
    is still allowed in the command, but it is a noise word.
   
    A user may perform SELECT, INSERT, etc. on a
    column if they hold that privilege for either the specific column or
    its whole table.  Granting the privilege at the table level and then
    revoking it for one column will not do what one might wish: the
    table-level grant is unaffected by a column-level operation.
   
    When a non-owner of an object attempts to GRANT privileges
    on the object, the command will fail outright if the user has no
    privileges whatsoever on the object.  As long as some privilege is
    available, the command will proceed, but it will grant only those
    privileges for which the user has grant options.  The GRANT ALL
    PRIVILEGES forms will issue a warning message if no grant options are
    held, while the other forms will issue a warning if grant options for
    any of the privileges specifically named in the command are not held.
    (In principle these statements apply to the object owner as well, but
    since the owner is always treated as holding all grant options, the
    cases can never occur.)
   
    It should be noted that database superusers can access
    all objects regardless of object privilege settings.  This
    is comparable to the rights of root in a Unix system.
    As with root, it's unwise to operate as a superuser
    except when absolutely necessary.
   
    If a superuser chooses to issue a GRANT or REVOKE
    command, the command is performed as though it were issued by the
    owner of the affected object.  In particular, privileges granted via
    such a command will appear to have been granted by the object owner.
    (For role membership, the membership appears to have been granted
    by the containing role itself.)
   
    GRANT and REVOKE can also be done by a role
    that is not the owner of the affected object, but is a member of the role
    that owns the object, or is a member of a role that holds privileges
    WITH GRANT OPTION on the object.  In this case the
    privileges will be recorded as having been granted by the role that
    actually owns the object or holds the privileges
    WITH GRANT OPTION.  For example, if table
    t1 is owned by role g1, of which role
    u1 is a member, then u1 can grant privileges
    on t1 to u2, but those privileges will appear
    to have been granted directly by g1.  Any other member
    of role g1 could revoke them later.
   
    If the role executing GRANT holds the required privileges
    indirectly via more than one role membership path, it is unspecified
    which containing role will be recorded as having done the grant.  In such
    cases it is best practice to use SET ROLE to become the
    specific role you want to do the GRANT as.
   
    Granting permission on a table does not automatically extend
    permissions to any sequences used by the table, including
    sequences tied to SERIAL columns.  Permissions on
    sequences must be set separately.
   
See Section 5.7 for more information about specific privilege types, as well as how to inspect objects' privileges.
   Grant insert privilege to all users on table films:
GRANT INSERT ON films TO PUBLIC;
   Grant all available privileges to user manuel on view
   kinds:
GRANT ALL PRIVILEGES ON kinds TO manuel;
   Note that while the above will indeed grant all privileges if executed by a
   superuser or the owner of kinds, when executed by someone
   else it will only grant those permissions for which the someone else has
   grant options.
  
   Grant membership in role admins to user joe:
GRANT admins TO joe;
    According to the SQL standard, the PRIVILEGES
    key word in ALL PRIVILEGES is required.  The
    SQL standard does not support setting the privileges on more than
    one object per command.
   
    PostgreSQL allows an object owner to revoke their
    own ordinary privileges: for example, a table owner can make the table
    read-only to themselves by revoking their own INSERT,
    UPDATE, DELETE, and TRUNCATE
    privileges.  This is not possible according to the SQL standard.  The
    reason is that PostgreSQL treats the owner's
    privileges as having been granted by the owner to themselves; therefore they
    can revoke them too.  In the SQL standard, the owner's privileges are
    granted by an assumed entity “_SYSTEM”.  Not being
    “_SYSTEM”, the owner cannot revoke these rights.
   
    According to the SQL standard, grant options can be granted to
    PUBLIC; PostgreSQL only supports granting grant options
    to roles.
   
    The SQL standard allows the GRANTED BY option to
    specify only CURRENT_USER or
    CURRENT_ROLE.  The other variants are PostgreSQL
    extensions.
   
    The SQL standard provides for a USAGE privilege
    on other kinds of objects: character sets, collations,
    translations.
   
    In the SQL standard, sequences only have a USAGE
    privilege, which controls the use of the NEXT VALUE FOR
    expression, which is equivalent to the
    function nextval in PostgreSQL.  The sequence
    privileges SELECT and UPDATE are
    PostgreSQL extensions.  The application of the
    sequence USAGE privilege to
    the currval function is also a PostgreSQL extension (as
    is the function itself).
   
Privileges on databases, tablespaces, schemas, languages, and configuration parameters are PostgreSQL extensions.