Hi, Alexander! On Apr 21, Alexander Barkov wrote:

Hi Sergei,

Please review a patch for MDEV-8024.

It's needed to as a pre-requisite for "MDEV-7950 Item_func::type() takes 0.26% in OLTP RO"

Looks ok. Just a few comments:

diff --git a/sql/item.cc b/sql/item.cc index e9bbdc7..502b8ae 100644 --- a/sql/item.cc +++ b/sql/item.cc @@ -59,6 +59,21 @@ bool cmp_items(Item *a, Item *b) }

+void +Used_tables_and_const_cache:: + used_tables_and_const_cache_update_and_join(List<Item> &list) +{ + List_iterator_fast<Item> li(list); + Item *item; + while ((item=li++)) + { + item->update_used_tables(); + used_tables_and_const_cache_join(item); + } +}

Why didn't you put that in the header? It's as small as the other used_tables_and_const_cache_update_and_join().

/***************************************************************************** ** Item functions *****************************************************************************/ diff --git a/sql/item_func.h b/sql/item_func.h index 653c08e..c78c585 100644 --- a/sql/item_func.h +++ b/sql/item_func.h @@ -1367,8 +1362,7 @@ class Item_udf_func :public Item_func { DBUG_ASSERT(fixed == 0); bool res= udf.fix_fields(thd, this, arg_count, args); - used_tables_cache= udf.used_tables_cache; - const_item_cache= udf.const_item_cache; + used_tables_and_const_cache_copy(udf.used_tables_and_const_cache());

why not used_tables_and_const_cache_copy(udf) ?

fixed= 1; return res; } diff --git a/sql/item_func.cc b/sql/item_func.cc index 50bc85f..4007d6b 100644 --- a/sql/item_func.cc +++ b/sql/item_func.cc @@ -178,8 +178,44 @@ Item_func::fix_fields(THD *thd, Item **ref) Item **arg,**arg_end; uchar buff[STACK_BUFF_ALLOC]; // Max argument in function

- used_tables_cache= not_null_tables_cache= 0; - const_item_cache=1; + // used_tables_and_const_cache_init(); // QQ: is it needed, for safety?

Add an assert, please

+ /* + Comments about the commented used_tables_and_const_cache_init() above:

Regards, Sergei