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MDEV-6879: Dereference of NULL primary_file->table in DsMrr_impl::get_disk_sweep_mrr_cost()

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(Attempt #2)
- Don't attempt to use BKA for materialized derived tables. The 
  table is neither filled nor fully opened yet, so attempt to 
  call handler->multi_range_read_info() causes crash.
This commit is contained in:
Sergey Petrunya
2014-10-20 23:35:34 +04:00
parent 8925b4a935
commit 1a996bde1e
3 changed files with 72 additions and 1 deletions
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15
sql/sql_select.cc
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@ -10549,6 +10549,19 @@ uint check_join_cache_usage(JOIN_TAB *tab,
cache_level--;
}
/*
Don't use BKA for materialized tables. We could actually have a
meaningful use of BKA when linked join buffers are used.
The problem is, the temp.table is not filled (actually not even opened
properly) yet, and this doesn't let us call
handler->multi_range_read_info(). It is possible to come up with
estimates, etc. without acessing the table, but it seems not to worth the
effort now.
*/
if (tab->table->pos_in_table_list->is_materialized_derived())
no_bka_cache= true;
/*
Don't use join buffering if we're dictated not to by no_jbuf_after
(This is not meaningfully used currently)
@ -10615,7 +10628,7 @@ uint check_join_cache_usage(JOIN_TAB *tab,
if (tab->ref.is_access_triggered())
goto no_join_cache;
if (!tab->is_ref_for_hash_join())
if (!tab->is_ref_for_hash_join() && !no_bka_cache)
{
flags= HA_MRR_NO_NULL_ENDPOINTS | HA_MRR_SINGLE_POINT;
if (tab->table->covering_keys.is_set(tab->ref.key))