Add pg_upgrade C comment about why we check all relkinds for regtypes.

diff --git a/contrib/pg_upgrade/check.c b/contrib/pg_upgrade/check.c
index 8594d2617b286976424732b283661dc2584b8f8d..891eb9a9f0dd4ddcc30f2c22d85ada7a71712c5e 100644 (file)
--- a/contrib/pg_upgrade/check.c
+++ b/contrib/pg_upgrade/check.c
@@ -644,6 +644,11 @@ check_for_reg_data_type_usage(ClusterInfo *cluster)
                DbInfo     *active_db = &cluster->dbarr.dbs[dbnum];
                PGconn     *conn = connectToServer(cluster, active_db->db_name);
 
+               /*
+                *      While several relkinds don't store any data, e.g. views, they
+                *      can be used to define data types of other columns, so we
+                *      check all relkinds.
+                */
                res = executeQueryOrDie(conn,
                                                                "SELECT n.nspname, c.relname, a.attname "
                                                                "FROM   pg_catalog.pg_class c, "