[Info-vax] VSI roadmap

[Arne Vajhøj]

On 8/24/2023 1:31 PM, Johnny Billquist wrote:
> On 2023-08-24 16:05, Dave Froble wrote:
>> RMS keys are defined as locations in a data record.  Not sure I'd 
>> define that as "information about fields".  As far as I know, RMS 
>> (other than key definitions) knows nothing about data 
>> fields/columns/whatever.
> 
> RMS keys have a type (obviously). You can also have some meta-data, even 
> though I suspect it's mostly not used...

> Note both the name, and type information for each key. However, the name 
> have no function as such within RMS. At least not under RSX. But you can 
> put information there if you want to.

Pretty much same on VMS.

The manual for XABKEY lists among other fields:

XAB$B_DTP : key type and order
XAB$B_FLG : flags (incl. allowing duplicates or not)
XAB$L_KNM : name (only used for documentation)
XAB$W_POSn : position in record (only n=0 used if non segmented key)
XAB$B_SIZn : size  (only n=0 used if non segmented key)
XAB$B_REF : key number (0 is primay key)

Arne