diff options
Diffstat (limited to 'sql/sql_select.cc')
| -rw-r--r-- | sql/sql_select.cc | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/sql/sql_select.cc b/sql/sql_select.cc index 87459a4441b..0372a06c469 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -13884,7 +13884,16 @@ change_cond_ref_to_const(THD *thd, I_List<COND_CMP> *save_list, if ((tmp2=new COND_CMP(and_father,func))) save_list->push_back(tmp2); } - func->set_cmp_func(); + /* + LIKE can be optimized for BINARY/VARBINARY/BLOB columns, e.g.: + + from: WHERE CONCAT(c1)='const1' AND CONCAT(c1) LIKE 'const2' + to: WHERE CONCAT(c1)='const1' AND 'const1' LIKE 'const2' + + So make sure to use set_cmp_func() only for non-LIKE operators. + */ + if (functype != Item_func::LIKE_FUNC) + ((Item_bool_rowready_func2*) func)->set_cmp_func(); } } else if (can_change_cond_ref_to_const(func, left_item, right_item, @@ -13907,7 +13916,8 @@ change_cond_ref_to_const(THD *thd, I_List<COND_CMP> *save_list, if ((tmp2=new COND_CMP(and_father,func))) save_list->push_back(tmp2); } - func->set_cmp_func(); + if (functype != Item_func::LIKE_FUNC) + ((Item_bool_rowready_func2*) func)->set_cmp_func(); } } } |