maria-developers team mailing list archive

[Sergei Golubchik <serg@xxxxxxxxxxx>]

Hi, Nikita!

On Feb 08, Nikita Malyavin wrote:
> On Tue, Feb 5, 2019 at 10:37 AM Sergei Golubchik <serg@xxxxxxxxxxx> wrote:
> >
> > as discussed, let's give the constraint the same name as the period.
> > but don't forget to add a test where a user explicitly creates a
> > constraint with this name. Like
> >
> >   create or replace table t (id int primary key, s date, e date,
> >   period for mytime(s,e), constraint mytime (id < 100));
> 
> Oh, I thought You meant to leave it as is. Ok, but what about making it
> not a CHECK constraint? I mean, to make its name not overlapping with CHECK
> constraints namespace. This will mean that the user can create his own
> CHECK constraint with the same name, and have no syntax to drop PERIOD
> constraint. What do you think about it?

I thought you've wanted it a CHECK constraint. You've quoted the
standard proving your point of view.

> > > +create or replace table t (s timestamp(2), e timestamp(6),
> > > +period for mytime(s,e));
> > > +ERROR HY000: PERIOD FOR `mytime` fields types mismatch
> > > +create or replace table t (id int primary key, s int, e date,
> > > +period for mytime(s,e));
> > > +ERROR 42000: Incorrect column specifier for column 's'
> >
> > incorrect column _type_?
> 
> Just used already existed ER_WRONG_FIELD_SPEC. Any better ideas?

ok, let's keep it this way for now

> > > diff --git a/sql/table.h b/sql/table.h
> > > --- a/sql/table.h
> > > +++ b/sql/table.h
> > > @@ -1730,6 +1747,9 @@ class IS_table_read_plan;
> > >  /** The threshold size a blob field buffer before it is freed */
> > >  #define MAX_TDC_BLOB_SIZE 65536
> > >
> > > +/** number of bytes read by uint2korr and sint2korr */
> > > +#define korr2size 2
> >
> > No, that's silly. It's like #define TWO 2
> > Of course korr2size is 2. And korr3size is 3, and korr4size is 4.
> 
> Of course! That's the way to say "This variable was stored as a 2-byte
> tuple".

I mean, you didn't remove the magic number. It's still 2, and if you'd
like to change it to be 3, for example, you'd still need to go and
change the code everywhere.

> > That's why I suggested something like
> >
> >   #define fieldno_size   2
> >   #define fieldno_korr   uint2korr
> >   #define fieldno_store  int2store
> >
> Oh no, that'll add 9 new macros! And the number can grow...

What do you mean, it's just three new macros, like above. Where's 9?

Regards,
Sergei
Chief Architect MariaDB
and security@xxxxxxxxxxx