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

Author: Sergey Glukhov

sql/sql_join_buffer.cc

@@ -1,4 +1,4 @@
-/* Copyright (c) 2010, 2017, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2010, 2019, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -566,8 +566,8 @@ void JOIN_CACHE::filter_virtual_gcol_base_cols()
       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
@@ -577,24 +577,38 @@ 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().
+    */
+    auto bitbuf =
+      (my_bitmap_map *)alloc_root(tab->table()->in_use->mem_root,
+                                    table->s->column_bitmap_size);
+    auto 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.insert(std::make_pair(tab, 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);
     }
   }
@@ -614,10 +628,11 @@ void JOIN_CACHE::restore_virtual_gcol_base_cols()
     if (table->vfield == NULL)
       continue;
 
-    if (!bitmap_is_clear_all(&table->tmp_set))
+    auto saved = save_read_set_for_gcol.find(tab);
+    if (saved != save_read_set_for_gcol.end())
     {
-      bitmap_copy(table->read_set, &table->tmp_set);
-      bitmap_clear_all(&table->tmp_set);
+      DBUG_ASSERT(!bitmap_is_clear_all(saved->second));
+      bitmap_copy(table->read_set, saved->second);
     }
   }
 }

sql/sql_join_buffer.h

@@ -3,7 +3,7 @@
 
 #include "sql_executor.h"
 
-/* Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -18,6 +18,10 @@
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
 
+
+#include "memroot_allocator.h"
+#include <unordered_map>
+
 /** @file Join buffer classes */
 
 /* 
@@ -30,6 +34,25 @@
 #define CACHE_VARSTR1   3        /* short string value (length takes 1 byte) */ 
 #define CACHE_VARSTR2   4        /* long string value (length takes 2 bytes) */
 
+
+/**
+  std::unordered_map, but allocated on a MEM_ROOT.
+*/
+template <class Key, class Value, class Hash = std::hash<Key>,
+          class KeyEqual = std::equal_to<Key>>
+class memroot_unordered_map
+    : public std::unordered_map<
+          Key, Value, Hash, KeyEqual,
+          Memroot_allocator<std::pair<const Key, Value>>> {
+ public:
+  memroot_unordered_map(MEM_ROOT *mem_root)
+      : std::unordered_map<Key, Value, Hash, KeyEqual,
+                           Memroot_allocator<std::pair<const Key, Value>>>(
+            /*bucket_count=*/10, Hash(), KeyEqual(),
+            Memroot_allocator<std::pair<const Key, Value>>(mem_root)) {}
+};
+
+
 /*
   The CACHE_FIELD structure used to describe fields of records that
   are written into a join cache buffer from record buffers and backward.
@@ -98,6 +121,12 @@ class JOIN_CACHE :public QEP_operation
   /* 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.
+  */
+  memroot_unordered_map<QEP_TAB *, MY_BITMAP *> save_read_set_for_gcol;
+
 protected:
 
   /* 3 functions below actually do not use the hidden parameter 'this' */ 
@@ -460,8 +489,10 @@ class JOIN_CACHE :public QEP_operation
     linked.
   */
   JOIN_CACHE(JOIN *j, QEP_TAB *qep_tab_arg, JOIN_CACHE *prev)
-    : QEP_operation(qep_tab_arg), join(j), buff(NULL), prev_cache(prev),
-    next_cache(NULL)
+    : 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)
     {
       if (prev_cache)
         prev_cache->next_cache= this;