information_schema.constraint_column_usage and key_column_usage should

not discriminate against system columns, since we support constraints on
system columns, and in fact constraints on OID are moderately useful.

diff --git a/src/backend/catalog/information_schema.sql b/src/backend/catalog/information_schema.sql
index 9764097044076c8d8256a72f0388306bddc68e60..afdf14f1a35851dd7e058cfb56399ef95a899f34 100644 (file)
--- a/src/backend/catalog/information_schema.sql
+++ b/src/backend/catalog/information_schema.sql
@@ -434,7 +434,6 @@ CREATE VIEW constraint_column_usage AS
             AND c.connamespace = nc.oid
             AND c.contype = 'c'
             AND r.relkind = 'r'
-            AND a.attnum > 0
             AND NOT a.attisdropped
 
         UNION ALL
@@ -448,7 +447,6 @@ CREATE VIEW constraint_column_usage AS
             AND nc.oid = c.connamespace
             AND (CASE WHEN c.contype = 'f' THEN r.oid = c.confrelid AND c.confkey[pos.n] = a.attnum
                       ELSE r.oid = c.conrelid AND c.conkey[pos.n] = a.attnum END)
-            AND a.attnum > 0
             AND NOT a.attisdropped
             AND c.contype IN ('p', 'u', 'f')
             AND r.relkind = 'r'
@@ -683,7 +681,6 @@ CREATE VIEW key_column_usage AS
           AND r.oid = c.conrelid
           AND nc.oid = c.connamespace
           AND c.conkey[pos.n] = a.attnum
-          AND a.attnum > 0
           AND NOT a.attisdropped
           AND c.contype IN ('p', 'u', 'f')
           AND r.relkind = 'r'