MDEV-7674: ANALYZE shows r_rows=0

Change r_rows to be double

3 files changed, 14 insertions, 20 deletions

diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index 37060a6e133..5b0d04dc4a9 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -2454,8 +2454,7 @@ void THD::make_explain_field_list(List<Item> &field_list, uint8 explain_flags,
                                                  MYSQL_TYPE_LONGLONG));
   if (is_analyze)
   {
-    field_list.push_back(item= new Item_return_int("r_rows", 10,
-                                                   MYSQL_TYPE_LONGLONG));
+    field_list.push_back(item= new Item_float("r_rows", 0.1234, 10, 4));
     item->maybe_null=1;
   }
 
diff --git a/sql/sql_explain.cc b/sql/sql_explain.cc
index c68f86ce72c..aa16a744e83 100644
--- a/sql/sql_explain.cc
+++ b/sql/sql_explain.cc
@@ -298,7 +298,7 @@ int print_explain_row(select_result_sink *result,
                       const char *key_len,
                       const char *ref,
                       ha_rows *rows,
-                      ha_rows *r_rows,
+                      double *r_rows,
                       double r_filtered,
                       const char *extra)
 {
@@ -356,10 +356,7 @@ int print_explain_row(select_result_sink *result,
   if (is_analyze)
   {
     if (r_rows)
-    {
-      item_list.push_back(new Item_int(*r_rows, 
-                                       MY_INT64_NUM_DECIMAL_DIGITS));
-    }
+      item_list.push_back(new Item_float(*r_rows, 2));
     else
       item_list.push_back(item_null);
   }
@@ -472,9 +469,8 @@ int Explain_union::print_explain(Explain_query *query,
   /* `r_rows` */
   if (is_analyze)
   {
-    ha_rows avg_rows= fake_select_lex_tracker.get_avg_rows();
-    item_list.push_back(new Item_int((longlong) (ulonglong) avg_rows,
-                                      MY_INT64_NUM_DECIMAL_DIGITS));
+    double avg_rows= fake_select_lex_tracker.get_avg_rows();
+    item_list.push_back(new Item_float(avg_rows, 2));
   }
 
   /* `filtered` */
@@ -1004,9 +1000,8 @@ int Explain_table_access::print_explain(select_result_sink *output, uint8 explai
     }
     else
     {
-      ha_rows avg_rows= tracker.get_avg_rows();
-      item_list.push_back(new Item_int((longlong) (ulonglong) avg_rows,
-                                        MY_INT64_NUM_DECIMAL_DIGITS));
+      double avg_rows= tracker.get_avg_rows();
+      item_list.push_back(new Item_float(avg_rows, 2));
     }
   }
 
@@ -1289,8 +1284,8 @@ void Explain_table_access::print_explain_json(Explain_query *query,
     writer->add_member("r_rows");
     if (tracker.has_scans())
     {
-      ha_rows avg_rows= tracker.get_avg_rows();
-      writer->add_ll(avg_rows);
+      double avg_rows= tracker.get_avg_rows();
+      writer->add_double(avg_rows);
     }
     else
       writer->add_null();
@@ -1756,7 +1751,7 @@ int Explain_update::print_explain(Explain_query *query,
     "Using index condition" is also not possible (which is an unjustified limitation)
   */
   double r_filtered= 100 * tracker.get_filtered_after_where();
-  ha_rows r_rows= tracker.get_avg_rows();
+  double r_rows= tracker.get_avg_rows();
 
   print_explain_row(output, explain_flags, is_analyze,
                     1, /* id */
@@ -1877,8 +1872,8 @@ void Explain_update::print_explain_json(Explain_query *query,
   /* `r_rows` */
   if (is_analyze && tracker.has_scans())
   {
-    ha_rows avg_rows= tracker.get_avg_rows();
-    writer->add_member("r_rows").add_ll(avg_rows);
+    double avg_rows= tracker.get_avg_rows();
+    writer->add_member("r_rows").add_double(avg_rows);
   }
  
   /* UPDATE/DELETE do not produce `filtered` estimate */
diff --git a/sql/sql_explain.h b/sql/sql_explain.h
index c4bfa4d09bf..970edf7800d 100644
--- a/sql/sql_explain.h
+++ b/sql/sql_explain.h
@@ -44,9 +44,9 @@ public:
 
   bool has_scans() { return (r_scans != 0); }
   ha_rows get_loops() { return r_scans; }
-  ha_rows get_avg_rows()
+  double get_avg_rows()
   {
-    return r_scans ? (ha_rows)rint((double) r_rows / r_scans): 0;
+    return r_scans ? ((double)r_rows / r_scans): 0;
   }
 
   double get_filtered_after_where()