maria-developers team mailing list archive

[Sergei Golubchik <serg@xxxxxxxxxxx>]

Hi, Oleksandr!

On Feb 26, Oleksandr Byelkin wrote:
> On Wed, Feb 26, 2020 at 1:44 PM Sergei Golubchik <serg@xxxxxxxxxxx> wrote:
> 
> > Hi, Sanja!
> >
> > _some_ comments are below.
> >
> > The main thing, I still don't understand your changes in sql_select.cc.
> >
> > Why did you create separate counters and code paths with if() for CYCLE?
> > I'd think it could be just a generalization of DISTINCT
> 
> DISTINCT makes all fields distinct, except hidden, I need also except come
> other (or better say by list of not hidden)

Exactly. I thought DISTINCT will be just CYCLE with an empty list of
non-distinct columns. Or something like that. Not like

  if (cycle) {
    cycle code
  } else {
    distinct code
  }

> > > --- a/sql/sql_cte.cc
> > > +++ b/sql/sql_cte.cc
> > > @@ -982,6 +982,38 @@ With_element::rename_columns_of_derived_unit(THD *thd,
> >
> > are you sure what you're doing below can still be called
> > "rename_columns_of_derived_unit" ?
> 
> I can rename it to prepare_olumns_of_derived_unit, is it OK?

anything you like :)

> > > +opt_cycle:
> > > +         /* empty */
> > > +         { $$= NULL; }
> > > +         |
> > > +         CYCLE_SYM
> > > +         {
> > > +           if (!Lex->curr_with_clause->with_recursive)
> > > +           {
> > > +             thd->parse_error(ER_SYNTAX_ERROR, $1.pos());
> > > +           }
> > > +         }
> > > +         '(' with_column_list ')'
> >
> > Where did you see that the standard requires parentheses here?
> 
> Maybe in ORACLE docs... but without it it creates a lot of conflicts.

The standard says no parentheses. What kind of conflicts do you get?

Regards,
Sergei
VP of MariaDB Server Engineering
and security@xxxxxxxxxxx