Fixed bug #29338.

Optimization of queries with DETERMINISTIC functions in the
WHERE clause was not effective: sequential scan was always
used.
Now a SF with the DETERMINISTIC flags is treated as constant
when it's arguments are constants (or a SF doesn't has arguments).

2 files changed, 11 insertions, 1 deletions

diff --git a/sql/item_func.cc b/sql/item_func.cc
index b256ce4624a..e05f0a45083 100644
--- a/sql/item_func.cc
+++ b/sql/item_func.cc
@@ -5591,5 +5591,15 @@ Item_func_sp::fix_fields(THD *thd, Item **ref)
     
 #endif /* ! NO_EMBEDDED_ACCESS_CHECKS */
   }
+  if (!m_sp->m_chistics->detistic)
+   used_tables_cache |= RAND_TABLE_BIT;
   DBUG_RETURN(res);
 }
+
+
+void Item_func_sp::update_used_tables()
+{
+  Item_func::update_used_tables();
+  if (!m_sp->m_chistics->detistic)
+   used_tables_cache |= RAND_TABLE_BIT;
+}
diff --git a/sql/item_func.h b/sql/item_func.h
index 9a0201cb28b..56b5e75652c 100644
--- a/sql/item_func.h
+++ b/sql/item_func.h
@@ -1467,7 +1467,7 @@ public:
   virtual ~Item_func_sp()
   {}
 
-  table_map used_tables() const { return RAND_TABLE_BIT; }
+  void update_used_tables();
 
   void cleanup();