From 709a0a131021135e9fb7a2095fcfcbc223dfb126 Mon Sep 17 00:00:00 2001 From: Igor Babaev Date: Wed, 26 May 2010 13:18:18 -0700 Subject: MWL#106: Backport optimizations for derived tables and views. The main consolidated patch. --- sql/item_func.cc | 30 +++++++++++++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-) (limited to 'sql/item_func.cc') diff --git a/sql/item_func.cc b/sql/item_func.cc index 0676ce4f633..6ddff0511a7 100644 --- a/sql/item_func.cc +++ b/sql/item_func.cc @@ -192,7 +192,6 @@ Item_func::fix_fields(THD *thd, Item **ref) with_sum_func= with_sum_func || item->with_sum_func; used_tables_cache|= item->used_tables(); - not_null_tables_cache|= item->not_null_tables(); const_item_cache&= item->const_item(); with_subselect|= item->with_subselect; } @@ -206,6 +205,21 @@ Item_func::fix_fields(THD *thd, Item **ref) } +bool +Item_func::eval_not_null_tables(uchar *opt_arg) +{ + Item **arg,**arg_end; + if (arg_count) + { + for (arg=args, arg_end=args+arg_count; arg != arg_end ; arg++) + { + not_null_tables_cache|= (*arg)->not_null_tables(); + } + } + return FALSE; +} + + void Item_func::fix_after_pullout(st_select_lex *new_parent, Item **ref) { Item **arg,**arg_end; @@ -3895,6 +3909,20 @@ bool Item_func_set_user_var::fix_fields(THD *thd, Item **ref) entry->collation.set(args[0]->collation.collation, DERIVATION_IMPLICIT); collation.set(entry->collation.collation, DERIVATION_IMPLICIT); cached_result_type= args[0]->result_type(); + { + /* + When this function is used in a derived table/view force the derived + table to be materialized to preserve possible side-effect of setting a + user variable. + */ + SELECT_LEX_UNIT *unit= thd->lex->current_select->master_unit(); + TABLE_LIST *derived; + for (derived= unit->derived; + derived; + derived= derived->select_lex->master_unit()->derived) + derived->set_materialized_derived(); + } + return FALSE; } -- cgit v1.2.1