Addressed all remaining issues from the review of the patch

that introduced engine independent persistent statistics.
In particular:
- added an enumeration type for possible values of the system
  variable use_stat_tables
- renamed KEY::real_rec_per_key to KEY::actual_rec_per_key
- optimized the collection of statistical data for any primary
  key defined only on one column.
  

1 files changed, 2 insertions, 1 deletions

diff --git a/sql/sql_join_cache.cc b/sql/sql_join_cache.cc
index 225bb413195..ac96746c389 100644
--- a/sql/sql_join_cache.cc
+++ b/sql/sql_join_cache.cc
@@ -3812,7 +3812,8 @@ uint JOIN_TAB_SCAN_MRR::aux_buffer_incr(ulong recno)
   uint incr= 0;
   TABLE_REF *ref= &join_tab->ref;
   TABLE *tab= join_tab->table;
-  uint rec_per_key= tab->key_info[ref->key].real_rec_per_key(ref->key_parts-1);
+  uint rec_per_key=
+    tab->key_info[ref->key].actual_rec_per_key(ref->key_parts-1);
   set_if_bigger(rec_per_key, 1);
   if (recno == 1)
     incr=  ref->key_length + tab->file->ref_length;