Add pg_upgrade comment about mismatch error

Add comment stating that constraint and index names must match.

diff --git a/contrib/pg_upgrade/info.c b/contrib/pg_upgrade/info.c
index 22504427065d88226ebb57174cffb50a02cd11d5..11ceb70567685c8c64a91ec165afdcad3034e6e8 100644 (file)
--- a/contrib/pg_upgrade/info.c
+++ b/contrib/pg_upgrade/info.c
@@ -61,6 +61,9 @@ gen_db_file_maps(DbInfo *old_db, DbInfo *new_db,
                 * 9.0, TOAST relation names always use heap table oids, hence we
                 * cannot check relation names when upgrading from pre-9.0. Clusters
                 * upgraded to 9.0 will get matching TOAST names.
+                * If index names don't match primary key constraint names, this will
+                * fail because pg_dump dumps constraint names and pg_upgrade checks
+                * index names.
                 */
                if (strcmp(old_rel->nspname, new_rel->nspname) != 0 ||
                        ((GET_MAJOR_VERSION(old_cluster.major_version) >= 900 ||