[Info-vax] OpenVMS - DCL - Data entry filtering

[JF Mezei]

On 15-03-30 10:12, Stephen Hoffman wrote:

> data and accessors and logging and the rest.   You blow past what RMS 
> can do.   You might well reach the absurdity of directly rummaging 
> SYSUAF.DAT, as I and others have implemented. 

ALL-IN-1 provided interface to SYSUAF which was field based, independent
of actual layout. DCL didn't. So people rummaged because of lack of API
that could have provided field level access to those files. (and then
allowed those files to change).

Here is a question which has always bothered me. Database systems have
very opaque storage and indexing. (to me at least). Heck, I don't even
know which actual files store the data, index and what not.

But if one were to compare RMS with the low level database storage in
file(s), would the indexing and buckets etc of RMS end up competitive
with how databases organise the data and do record searches/lookups ?

MySQL seems to have a default file organisation that appears sequential
to me. ( so I use a different one which has indexed records where you
specify key fields, mostly because this is what I am familiar with)

Seems to me tha a sequeintial file organsiation can't be all that
efficient when doing database lookups by a name, or record number etc.
It is fine when most of your lookups are wildcard searches. But not so
much when doing simple loomup by a key such as employee number.