Re: Max length of a VARYING field

[Scott Klement <rpg400-l@xxxxxxxxxxxxxxxx>]

When I teach the VARYING keyword, I always teach it this way:

     D  myVar          s            500A   varying

500 is the maximum number of characters that can be stored.
varying means that it's not always that large.

If you changed the spec to look like this:

     D  myVar          s            500A   varying(*max64kb)

Then it'd be rather unclear when I said that 500 was the maximum number 
of characters.  It's hard to explain why both 500 and 64k are the 
maximum in the same statement.  Not only that, but it's quite a bit of 
typing to type Varying(*max128tb) (or any of the *MAX things).

Please, lets not make things more complicated to teach then they already 
are.

Err... also, I'm not sure that we need a *MAX32KB.  Is that just for 
compatibility with older releases, or what?


Joe Pluta wrote:
> Okay, how about something straightforward:
>
> VARYING(*MAX32KB)
> VARYING(*MAX2GB)
> VARYING(*MAX128TB)
>
> The numbers are based on 2, 4 and 6 byte prefixes, but with one bit unused
> (not sure why one bit is unused, except that 32KB is the current maximum, so
> I kept the pattern going).
>
> Let VARYING default to VARYING(*MAX32KB) and all is well.
>
> I stopped at 48-bit addressing (technically 47-bit) because it's just hard
> for me to conceive of a situation where one would need more than 128
> terabytes for a single field.  If you decided to go to 63 bits, I guess you
> do *MAX8EB (eight exabytes).
>
> Joe