MDEV-18755 Assertion `inited==INDEX' failed in handler::ha_index_read_map

When the chosen execution plan accesses a join table employing a range
rowid filter a quick select to scan this range has to be built. This
quick select is built by a call of SQL_SELECT::test_quick_select().
At this call the function should allow to evaluate only single index
range scans. In order to be able to do this a new parameter was added
to this function.

3 files changed, 28 insertions, 17 deletions

diff --git a/sql/opt_range.cc b/sql/opt_range.cc
index fcf0d2228a5..1e60bb9ae92 100644
--- a/sql/opt_range.cc
+++ b/sql/opt_range.cc
@@ -2586,6 +2586,9 @@ static int fill_used_fields_bitmap(PARAM *param)
       limit             Query limit
       force_quick_range Prefer to use range (instead of full table scan) even
                         if it is more expensive.
+      remove_false_parts_of_where  Remove parts of OR-clauses for which range
+                                   analysis produced SEL_TREE(IMPOSSIBLE)
+      only_single_index_range_scan Evaluate only single index range scans
 
   NOTES
     Updates the following in the select parameter:
@@ -2644,7 +2647,8 @@ int SQL_SELECT::test_quick_select(THD *thd, key_map keys_to_use,
 				  table_map prev_tables,
 				  ha_rows limit, bool force_quick_range, 
                                   bool ordered_output,
-                                  bool remove_false_parts_of_where)
+                                  bool remove_false_parts_of_where,
+                                  bool only_single_index_range_scan)
 {
   uint idx;
   double scan_time;
@@ -2824,7 +2828,7 @@ int SQL_SELECT::test_quick_select(THD *thd, key_map keys_to_use,
     }
 
     TABLE_READ_PLAN *best_trp= NULL;
-    TRP_GROUP_MIN_MAX *group_trp;
+    TRP_GROUP_MIN_MAX *group_trp= NULL;
     double best_read_time= read_time;
 
     if (cond)
@@ -2859,7 +2863,8 @@ int SQL_SELECT::test_quick_select(THD *thd, key_map keys_to_use,
       Try to construct a QUICK_GROUP_MIN_MAX_SELECT.
       Notice that it can be constructed no matter if there is a range tree.
     */
-    group_trp= get_best_group_min_max(&param, tree, best_read_time);
+    if (!only_single_index_range_scan)
+      group_trp= get_best_group_min_max(&param, tree, best_read_time);
     if (group_trp)
     {
       param.table->quick_condition_rows= MY_MIN(group_trp->records,
@@ -2907,7 +2912,8 @@ int SQL_SELECT::test_quick_select(THD *thd, key_map keys_to_use,
         table deletes.
       */
       if ((thd->lex->sql_command != SQLCOM_DELETE) && 
-           optimizer_flag(thd, OPTIMIZER_SWITCH_INDEX_MERGE))
+           optimizer_flag(thd, OPTIMIZER_SWITCH_INDEX_MERGE) &&
+          !only_single_index_range_scan)
       {
         /*
           Get best non-covering ROR-intersection plan and prepare data for
@@ -2935,7 +2941,8 @@ int SQL_SELECT::test_quick_select(THD *thd, key_map keys_to_use,
       */
       if (param.table->covering_keys.is_clear_all() &&
           optimizer_flag(thd, OPTIMIZER_SWITCH_INDEX_MERGE) &&
-          optimizer_flag(thd, OPTIMIZER_SWITCH_INDEX_MERGE_SORT_INTERSECT))
+          optimizer_flag(thd, OPTIMIZER_SWITCH_INDEX_MERGE_SORT_INTERSECT) &&
+          !only_single_index_range_scan)
       {
         if ((intersect_trp= get_best_index_intersect(&param, tree,
                                                     best_read_time)))
@@ -2948,7 +2955,7 @@ int SQL_SELECT::test_quick_select(THD *thd, key_map keys_to_use,
       }
 
       if (optimizer_flag(thd, OPTIMIZER_SWITCH_INDEX_MERGE) &&
-          head->stat_records() != 0)
+          head->stat_records() != 0 && !only_single_index_range_scan)
       {
         /* Try creating index_merge/ROR-union scan. */
         SEL_IMERGE *imerge;
diff --git a/sql/opt_range.h b/sql/opt_range.h
index 7e92e1f54ee..2dab90b9f69 100644
--- a/sql/opt_range.h
+++ b/sql/opt_range.h
@@ -1645,7 +1645,8 @@ class SQL_SELECT :public Sql_alloc {
   {
     key_map tmp;
     tmp.set_all();
-    return test_quick_select(thd, tmp, 0, limit, force_quick_range, FALSE, FALSE) < 0;
+    return test_quick_select(thd, tmp, 0, limit, force_quick_range,
+                             FALSE, FALSE, FALSE) < 0;
   }
   /* 
     RETURN
@@ -1662,7 +1663,8 @@ class SQL_SELECT :public Sql_alloc {
   }
   int test_quick_select(THD *thd, key_map keys, table_map prev_tables,
 			ha_rows limit, bool force_quick_range, 
-                        bool ordered_output, bool remove_false_parts_of_where);
+                        bool ordered_output, bool remove_false_parts_of_where,
+                        bool only_single_index_range_scan);
 };
 
 
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 4f98153d752..211898f46d0 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -1606,7 +1606,7 @@ bool JOIN::make_range_rowid_filters()
     tab->table->force_index= true;
     (void) sel->test_quick_select(thd, filter_map, (table_map) 0,
                                   (ha_rows) HA_POS_ERROR,
-				  true, false, true);
+                                  true, false, true, true);
     tab->table->force_index= force_index_save;
     if (thd->is_error())
       goto no_filter;
@@ -4623,7 +4623,8 @@ static ha_rows get_quick_record_count(THD *thd, SQL_SELECT *select,
                 select->test_quick_select(thd, *(key_map *)keys,
                                           (table_map) 0,
                                           limit, 0, FALSE,
-                                          TRUE /* remove_where_parts*/)) ==
+                                          TRUE,     /* remove_where_parts*/
+                                          FALSE)) ==
                1))
       DBUG_RETURN(select->quick->records);
     if (unlikely(error == -1))
@@ -11356,7 +11357,7 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond)
 					OPTION_FOUND_ROWS ?
 					HA_POS_ERROR :
 					join->unit->select_limit_cnt), 0,
-                                        FALSE, FALSE) < 0)
+                                       FALSE, FALSE, FALSE) < 0)
             {
 	      /*
 		Before reporting "Impossible WHERE" for the whole query
@@ -11370,7 +11371,7 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond)
                                           OPTION_FOUND_ROWS ?
                                           HA_POS_ERROR :
                                           join->unit->select_limit_cnt),0,
-                                          FALSE, FALSE) < 0)
+                                         FALSE, FALSE, FALSE) < 0)
 		DBUG_RETURN(1);			// Impossible WHERE
             }
             else
@@ -20899,7 +20900,8 @@ test_if_quick_select(JOIN_TAB *tab)
 
   int res= tab->select->test_quick_select(tab->join->thd, tab->keys,
                                           (table_map) 0, HA_POS_ERROR, 0,
-                                          FALSE, /*remove where parts*/FALSE);
+                                          FALSE, /*remove where parts*/FALSE,
+                                          FALSE);
   if (tab->explain_plan && tab->explain_plan->range_checked_fer)
     tab->explain_plan->range_checked_fer->collect_data(tab->select->quick);
 
@@ -22763,9 +22765,9 @@ test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit,
           res= select->test_quick_select(tab->join->thd, new_ref_key_map, 0,
                                          (tab->join->select_options &
                                           OPTION_FOUND_ROWS) ?
-                                         HA_POS_ERROR :
-                                         tab->join->unit->select_limit_cnt,TRUE,
-                                         TRUE, FALSE) <= 0;
+                                          HA_POS_ERROR :
+                                          tab->join->unit->select_limit_cnt,TRUE,
+                                         TRUE, FALSE, FALSE) <= 0;
           if (res)
           {
             select->cond= save_cond;
@@ -22867,7 +22869,7 @@ test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit,
                                 join->select_options & OPTION_FOUND_ROWS ?
                                 HA_POS_ERROR :
                                 join->unit->select_limit_cnt,
-                                TRUE, FALSE, FALSE);
+                                TRUE, FALSE, FALSE, FALSE);
 
       if (cond_saved)
         select->cond= saved_cond;