Re: tuple radix sort

Hi John,

How about adding an assertion here:

```
diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 72c2c2995d8..bcc534136d7 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -2783,6 +2783,8 @@ radix_sort_recursive(SortTuple *begin, size_t n_elems, int level, Tuplesortstate
else
next_level = level + 1;

+ Assert(next_level > level);
+
for (uint8 *rp = remaining_partitions;
rp < remaining_partitions + num_partitions;
rp++)
```

It can help us catch some unexpected behaviors.

--
Regards,
ChangAo Chen