Hi, Sergei! On Fri, Feb 8, 2019 at 5:02 AM Sergei Golubchik <s...@mariadb.org> wrote:
> Hi, Nikita! > > On Feb 08, Nikita Malyavin wrote: > > On Fri, Feb 8, 2019 at 2:18 AM Sergei Golubchik <s...@mariadb.org> > wrote: > > > I thought you've wanted it a CHECK constraint. You've quoted the > > > standard proving your point of view. > > > > I've also quoted that it's name shouldn't match any existing > > constraint name:) > > yes, we have this issue for all auto-generated names, and the usual > workaround is to append _1, _2, etc until there's a free name. > > Okay, added to ALTER TABLE commit > > > > > 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. > > > > Oh, so You're really thinking on such refactoring, to change the sizes of > > metainfo types rapidly? Then that 👇makes sense: > > No, I don't. Changing storage format is very heavy and thus very rare > operation. > > I was just using it as an example, to show that embedding a magical > number in the name of a constant doesn't make it any less magical or the > code any easier to understand. "Easy to change" is a good rule, even if > you don't actually plan to change :) > > > > > 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? > > > > 3 for fieldno, 3 for field_name_len, 3 for key_count (WITHOUT OVERLAPS > > commit), and who knows -- I've also planned an flag in FOREIGN KEY > support. > > sure, they're different entities, there is no inherent rule why they all > should use the same storage width. So yes, 9 macros. Seems, the consensual solution is just to add size consts, one per category. I've updated the code. Are You good with that? -- Yours truly, Nikita Malyavin
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