Thread: AW: AW: [HACKERS] Re: atttypmod of 0

AW: AW: [HACKERS] Re: atttypmod of 0

From
Zeugswetter Andreas DBT
Date:
I guess I don't have a strong opinion on that. Since atttypmod is also
intended for
decimal and others, I think the default has to be type specific anyway,
like 0 digits after the comma for decimal.
I would prefer an atttypmod that does not include the VARHDRSZ for
varchar though.
Then it would simply be the max length (better for humans reading the
system catalog).
The default of zero would still be no problem I guess, since max zero
length is still nonsense.

Andreas

> > Yes, I think to change atttypmod to default to -1 would be the right
> > thing,
> > since the empty string '' really has a length of 0,
> > We could think of -1 as: We don't know how long this field will be.
> > 0 would mean the field has 0 bytes.
>
> Field has varlena == 4, so zero is not possible, but I could still
> change to -1 for clarity.
>

Re: AW: AW: [HACKERS] Re: atttypmod of 0

From
Bruce Momjian
Date:
>
> I guess I don't have a strong opinion on that. Since atttypmod is also
> intended for
> decimal and others, I think the default has to be type specific anyway,
> like 0 digits after the comma for decimal.
> I would prefer an atttypmod that does not include the VARHDRSZ for
> varchar though.
> Then it would simply be the max length (better for humans reading the
> system catalog).
> The default of zero would still be no problem I guess, since max zero
> length is still nonsense.

I indented to change it to -1 when we start using atttypmod for more
types that just char() and varchar().

--
Bruce Momjian
maillist@candle.pha.pa.us