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MDEV-16751: Server crashes in st_join_table::cleanup or TABLE_LIST::is_with_table_recursive_reference

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with join_cache_level>2

During muliple equality propagation for a query in which we have an IN subquery, the items in the select list of the
subquery may not be part of the multiple equality because there might be another occurence of the same field in the
where clause of the subquery.
So we keyuse_is_valid_for_access_in_chosen_plan function which expects the items in the select list of the subquery to
be same to the ones in the multiple equality (through these multiple equalities we create keyuse array).
The solution would be that we expect the same field not the same Item because when we have SEMI JOIN MATERIALIZATION SCAN,
we use copy back technique to copies back the materialised table fields to the original fields of the base tables.
This commit is contained in:
Varun Gupta
2018-07-25 14:20:16 +05:30
parent d567f1611e
commit f9b43c2565
5 changed files with 105 additions and 2 deletions
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9
sql/sql_select.cc
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@ -7445,8 +7445,13 @@ bool JOIN_TAB::keyuse_is_valid_for_access_in_chosen_plan(JOIN *join,
st_select_lex *sjm_sel= emb_sj_nest->sj_subq_pred->unit->first_select();
for (uint i= 0; i < sjm_sel->item_list.elements; i++)
{
if (sjm_sel->ref_pointer_array[i] == keyuse->val)
return true;
DBUG_ASSERT(sjm_sel->ref_pointer_array[i]->type() == Item::FIELD_ITEM);
if (keyuse->val->type() == Item::FIELD_ITEM)
{
Field *field = ((Item_field*)sjm_sel->ref_pointer_array[i])->field;
if (field->eq(((Item_field*)keyuse->val)->field))
return true;
}
}
return false;
}