Improve description of constraint_exclusion variable.

diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 4e3649d63d2441fd0c1b2829bc10ad20caa14237..ac484e3d20c75b9121ea118eec0dfa89e6549781 100644 (file)
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -464,9 +464,9 @@ static struct config_bool ConfigureNamesBool[] =
        },
        {
                {"constraint_exclusion", PGC_USERSET, QUERY_TUNING_OTHER,
-                       gettext_noop("Enables the planner to use constraints to limit table access."),
-                       gettext_noop("This prevents table access if the table constraints "
-                                                "guarantee that table access is not necessary.")
+                       gettext_noop("Enables the planner to use constraints to optimize queries."),
+                       gettext_noop("Child table scans will be skipped if their "
+                                                "constraints guarantee that no rows match the query.")
                },
                &constraint_exclusion,
                false, NULL, NULL