maria-developers team mailing list archive

[Sergei Golubchik <serg@xxxxxxxxxxx>]

Hi, Alexander!

On Oct 04, Alexander Barkov wrote:
> Hello Sergei,
> 
> Please review a patch for MDEV-13997.
> 
> It's needed for:
> MDEV-13995 MAX(timestamp) returns a wrong result near DST change
> and for:
> MDEV-4912 Add a plugin to field types (column types)
> 
> Thanks!

See some questions below.
I'm not yet familiar with new 10.3 type handler
code, not sure I understood everything correctly.

> commit 55eb354cbbeef818d739c69a700528decacd963d
> Author: Alexander Barkov <bar@xxxxxxxxxxx>
> Date:   Wed Oct 4 15:12:36 2017 +0400
> 
> diff --git a/sql/item.cc b/sql/item.cc
> index f609bfd..992215f 100644
> --- a/sql/item.cc
> +++ b/sql/item.cc
> @@ -109,6 +109,19 @@ void Item::push_note_converted_to_positive_complement(THD *thd)
>  }
>  
>  
> +longlong Item::val_datetime_packed_result()
> +{
> +  MYSQL_TIME ltime, tmp;
> +  if (get_date_result(&ltime, TIME_FUZZY_DATES | TIME_INVALID_DATES))
> +    return 0;
> +  if (ltime.time_type != MYSQL_TIMESTAMP_TIME)
> +    return pack_time(&ltime);
> +  if ((null_value= time_to_datetime_with_warn(current_thd, &ltime, &tmp, 0)))
> +    return 0;
> +  return pack_time(&tmp);

Hmm, it's used instead of the old Item_cache_temporal::cache_value()
but it's significantly more complex. What's the change in behavior?

> +}
> +
> +
>  /**
>    Get date/time/datetime.
>    Optionally extend TIME result to DATETIME.
> diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
> index 9954c66..90b150a 100644
> --- a/sql/item_cmpfunc.cc
> +++ b/sql/item_cmpfunc.cc
> @@ -2112,38 +2102,40 @@ bool Item_func_between::fix_length_and_dec_numeric(THD *thd)
>  }
>  
>  
> -longlong Item_func_between::val_int_cmp_temporal()
> +bool Item_func_between::fix_length_and_dec_temporal(THD *thd)
>  {
> -  THD *thd= current_thd;
> -  longlong value, a, b;
> -  Item *cache, **ptr;
> -  bool value_is_null, a_is_null, b_is_null;
> +  if (!thd->lex->is_ps_or_view_context_analysis())
> +  {
> +    for (uint i= 0; i < 3; i ++)
> +    {
> +      if (args[i]->const_item() &&
> +          args[i]->type_handler_for_comparison() != m_comparator.type_handler())

What does this condition mean?

> +      {
> +        Item_cache *cache= m_comparator.type_handler()->Item_get_cache(thd, args[i]);
> +        if (!cache || cache->setup(thd, args[i]))
> +          return true;
> +        thd->change_item_tree(&args[i], cache);
> +      }
> +    }
> +  }
> +  return false;
> +}
>  

Regards,
Sergei
Chief Architect MariaDB
and security@xxxxxxxxxxx