diff options
Diffstat (limited to 'sql/table.cc')
| -rw-r--r-- | sql/table.cc | 28 |
1 files changed, 16 insertions, 12 deletions
diff --git a/sql/table.cc b/sql/table.cc index 83ab3f357bf..10bd4056ac2 100644 --- a/sql/table.cc +++ b/sql/table.cc @@ -3462,7 +3462,6 @@ int TABLE_SHARE::init_from_sql_statement_string(THD *thd, bool write, char *sql_copy; handler *file; LEX *old_lex; - Query_arena *arena, backup; LEX tmp_lex; KEY *unused1; uint unused2; @@ -3489,11 +3488,6 @@ int TABLE_SHARE::init_from_sql_statement_string(THD *thd, bool write, old_lex= thd->lex; thd->lex= &tmp_lex; - arena= thd->stmt_arena; - if (arena->is_conventional()) - arena= 0; - else - thd->set_n_backup_active_arena(arena, &backup); /* THD::reset_db() does not set THD::db_charset, @@ -3545,8 +3539,6 @@ ret: lex_end(thd->lex); thd->reset_db(&db_backup); thd->lex= old_lex; - if (arena) - thd->restore_active_arena(arena, &backup); reenable_binlog(thd); thd->variables.character_set_client= old_cs; if (unlikely(thd->is_error() || error)) @@ -6760,7 +6752,7 @@ void TABLE_LIST::set_check_materialized() DBUG_ENTER("TABLE_LIST::set_check_materialized"); SELECT_LEX_UNIT *derived= this->derived; if (view) - derived= &view->unit; + derived= this->derived= &view->unit; DBUG_ASSERT(derived); DBUG_ASSERT(!derived->is_excluded()); if (!derived->first_select()->exclude_from_table_unique_test) @@ -9609,13 +9601,25 @@ bool TABLE_LIST::init_derived(THD *thd, bool init_view) { /* A subquery might be forced to be materialized due to a side-effect. */ if (!is_materialized_derived() && unit->can_be_merged() && - (unit->outer_select() && !unit->outer_select()->with_rownum) && + /* + Following is special case of + SELECT * FROM (<limited-select>) WHERE ROWNUM() <= nnn + */ + (unit->outer_select() && + !(unit->outer_select()->with_rownum && + unit->outer_select()->table_list.elements == 1 && + (thd->lex->sql_command == SQLCOM_SELECT || + !unit->outer_select()->is_query_topmost(thd)) && + !is_view())) && + (!thd->lex->with_rownum || (!first_select->group_list.elements && !first_select->order_list.elements)) && (is_view() || - (optimizer_flag(thd, OPTIMIZER_SWITCH_DERIVED_MERGE) && - !thd->lex->can_not_use_merged(1))) && + optimizer_flag(thd, OPTIMIZER_SWITCH_DERIVED_MERGE)) && + !thd->lex->can_not_use_merged() && + !((thd->lex->sql_command == SQLCOM_UPDATE_MULTI || + thd->lex->sql_command == SQLCOM_DELETE_MULTI) && !is_view()) && !is_recursive_with_table()) set_merged_derived(); else |