Bug#28652733 ASSERTION FAILED: !TABLE || (!TABLE->READ_SET || BITMAP_IS_SET(TABLE->READ_SET,

Author: Sergey Glukhov

sql/sql_join_buffer.cc

@@ -559,14 +559,16 @@ static void filter_gcol_for_dynamic_range_scan(QEP_TAB *const tab)
 
 void JOIN_CACHE::filter_virtual_gcol_base_cols()
 {
+  DBUG_ASSERT(save_read_set_for_gcol.size() == 0);
   for (QEP_TAB *tab= qep_tab - tables; tab < qep_tab; tab++)
   {
     TABLE *table= tab->table();
     if (table->vfield == NULL)
       continue;
 
     const uint index= tab->effective_index();
-    if (index != MAX_KEY && table->index_contains_some_virtual_gcol(index) &&
+    const bool cov_index =
+      index != MAX_KEY && table->index_contains_some_virtual_gcol(index) &&
         /*
           There are two cases:
           - If the table scan uses covering index scan, we can get the value
@@ -576,24 +578,40 @@ void JOIN_CACHE::filter_virtual_gcol_base_cols()
             After restore the base columns, the value of virtual generated
             columns can be calculated correctly.
         */
-        table->covering_keys.is_set(index))
+        table->covering_keys.is_set(index);
+
+    if (!(cov_index || tab->dynamic_range())) continue;
+
+    /*
+      Save of a copy of table->read_set in save_read_set so that it can be
+      restored. tmp_set cannot be used as recipient for this as it's already
+      used in other parts of JOIN_CACHE::init().
+    */
+    my_bitmap_map *bitbuf =
+      (my_bitmap_map *)alloc_root(tab->table()->in_use->mem_root,
+                                  table->s->column_bitmap_size);
+    MY_BITMAP *save_read_set =
+      (MY_BITMAP *)alloc_root(tab->table()->in_use->mem_root,
+                              sizeof(MY_BITMAP));
+    bitmap_init(save_read_set, bitbuf, table->s->fields, false);
+    bitmap_copy(save_read_set, table->read_set);
+    /*
+      restore_virtual_gcol_base_cols() will need old bitmap so we save a
+      reference to it.
+    */
+    save_read_set_for_gcol.push_back(save_read_set);
+
+    if (cov_index)
     {
-      DBUG_ASSERT(bitmap_is_clear_all(&table->tmp_set));
-      // Keep table->read_set in tmp_set so that it can be restored
-      bitmap_copy(&table->tmp_set, table->read_set);
       bitmap_clear_all(table->read_set);
       table->mark_columns_used_by_index_no_reset(index, table->read_set);
       if (table->s->primary_key != MAX_KEY)
         table->mark_columns_used_by_index_no_reset(table->s->primary_key,
                                                    table->read_set);
-      bitmap_intersect(table->read_set, &table->tmp_set);
+      bitmap_intersect(table->read_set, save_read_set);
     }
     else if (tab->dynamic_range())
     {
-      DBUG_ASSERT(bitmap_is_clear_all(&table->tmp_set));
-      // Keep table->read_set in tmp_set so that it can be restored
-      bitmap_copy(&table->tmp_set, table->read_set);
-
       filter_gcol_for_dynamic_range_scan(tab);
     }
   }
@@ -607,18 +625,26 @@ void JOIN_CACHE::filter_virtual_gcol_base_cols()
 
 void JOIN_CACHE::restore_virtual_gcol_base_cols()
 {
+  MY_BITMAP **save_read_set= save_read_set_for_gcol.begin();
+
   for (QEP_TAB *tab= qep_tab - tables; tab < qep_tab; tab++)
   {
     TABLE *table= tab->table();
     if (table->vfield == NULL)
       continue;
 
-    if (!bitmap_is_clear_all(&table->tmp_set))
-    {
-      bitmap_copy(table->read_set, &table->tmp_set);
-      bitmap_clear_all(&table->tmp_set);
-    }
+    const uint index= tab->effective_index();
+    const bool cov_index =
+      (index != MAX_KEY && table->index_contains_some_virtual_gcol(index) &&
+       table->covering_keys.is_set(index));
+
+    if (!(cov_index || tab->dynamic_range())) continue;
+
+    DBUG_ASSERT(!bitmap_is_clear_all(*save_read_set));
+    bitmap_copy(table->read_set, *save_read_set);
+    save_read_set++;
   }
+  DBUG_ASSERT(save_read_set == save_read_set_for_gcol.end());
 }
 
 /* 

sql/sql_join_buffer.h

@@ -2,6 +2,7 @@
 #define SQL_JOIN_CACHE_INCLUDED
 
 #include "sql_executor.h"
+#include "mem_root_array.h"
 
 /* Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
 
@@ -99,6 +100,11 @@ class JOIN_CACHE :public QEP_operation
   uint size_of_rec_len;
   /* Size of the offset of a field within a record in the cache */   
   uint size_of_fld_ofs;
+  /**
+    In init() there are several uses of TABLE::tmp_set, so one tmp_set isn't
+    enough; this one is specific of generated column handling.
+  */
+  Mem_root_array<MY_BITMAP*, true> save_read_set_for_gcol;
 
 protected:
 
@@ -463,6 +469,7 @@ class JOIN_CACHE :public QEP_operation
   */
   JOIN_CACHE(JOIN *j, QEP_TAB *qep_tab_arg, JOIN_CACHE *prev)
     : QEP_operation(qep_tab_arg),
+      save_read_set_for_gcol(qep_tab_arg->table()->in_use->mem_root),
       join(j), buff(NULL), prev_cache(prev),
       next_cache(NULL)
     {