Add sequence USAGE privileges to information schema

The sequence USAGE privilege is sufficiently similar to the SQL
standard that it seems reasonable to show in the information schema.
Also add some compatibility notes about it on the GRANT reference
page.

1 files changed, 12 insertions, 0 deletions

diff --git a/doc/src/sgml/ref/grant.sgml b/doc/src/sgml/ref/grant.sgml
index c5edaed153a..05f98bb6bb5 100644
--- a/doc/src/sgml/ref/grant.sgml
+++ b/doc/src/sgml/ref/grant.sgml
@@ -643,6 +643,18 @@ GRANT admins TO joe;
    </para>
 
    <para>
+    In the SQL standard, sequences only have a <literal>USAGE</literal>
+    privilege, which controls the use of the <literal>NEXT VALUE FOR</literal>
+    expression, which is equivalent to the
+    function <function>nextval</function> in PostgreSQL.  The sequence
+    privileges <literal>SELECT</literal> and <literal>UPDATE</literal> are
+    PostgreSQL extensions.  The application of the
+    sequence <literal>USAGE</literal> privilege to
+    the <literal>currval</literal> function is also a PostgreSQL extension (as
+    is the function itself).
+   </para>
+
+   <para>
     Privileges on databases, tablespaces, schemas, and languages are
     <productname>PostgreSQL</productname> extensions.
    </para>