Added hints about the reason, why the command string in

the view pg_stat_activity is missing, as per Bruces suggestion.

Jan

diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index 4407837..03166ea 100644 (file)
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -286,20 +286,24 @@ pg_stat_get_backend_activity(PG_FUNCTION_ARGS)
        PgStat_StatBeEntry *beentry;
        int32           beid;
        int                     len;
+       char       *activity;
        text       *result;
 
        beid = PG_GETARG_INT32(0);
 
        if ((beentry = pgstat_fetch_stat_beentry(beid)) == NULL)
-               PG_RETURN_NULL();
-
-       if (!superuser() && beentry->userid != GetUserId())
-               PG_RETURN_NULL();
+               activity = "<backend information not available>";
+       else if (!superuser() && beentry->userid != GetUserId())
+               activity = "<insufficient privilege>";
+       else if (*(beentry->activity) == '\0')
+               activity = "<command string not enabled>";
+       else
+               activity = beentry->activity;
 
-       len = strlen(beentry->activity);
+       len = strlen(activity);
        result = palloc(VARHDRSZ + len);
        VARATT_SIZEP(result) = VARHDRSZ + len;
-       memcpy(VARDATA(result), beentry->activity, len);
+       memcpy(VARDATA(result), activity, len);
 
        PG_RETURN_TEXT_P(result);
 }