>
> Hi!
>
> I have tried:
>
> create table tab (v1 char(4096), v2 char(4096), v3 char(4096));
>
> Then:
>
> insert into tab values('1');
>
> OK
>
> insert into tab values('1','2');
>
> Tuple is too big: size 8256.
>
> Well, I understand why, but type 'char' is *fixed* length type,
> so even if I don't use some attributes, it *must* be inserted
> with all spaces... At least, I expected this... In this case
> I must get "tuple is too big" even if I will insert "empty"
> record. It is not so - why?
NULL has zero length.
>
> And one more: when I use 'varchar' without size, I get variable
> length attribute similar to 'text', which is stored with actual
> length, without padding. If I will specify length, it will be
> stored without padding, but will occupy specified number of bytes
> *always*, but, when retrieved, will return actual number of characters.
> Why not store only actual length, even if maximum specified?
> And, it will be listed as attribute with length zero, not 'var',
> but *actually* it is variable length, same as 'text'...
It is just part of the way varchar works. Performance is slightly
better with fixed-length strings like this, perhaps.
- --
Bruce Momjian
maillist@candle.pha.pa.us
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