Re: Relational vs network vs hierarchic databases

"Dan" <guntermann_at_verizon.com> wrote in message news:Om%jd.368$z_4.155_at_trnddc07...

> Traversing by pointers is very, very fast. There is not doubt about it.
> However, there is a huge downside to hardcoding a data model by using
> pointers and fixed data segments. This should be obvious.
>
> I believe what Laconic2 meant by saying "all other things equal" is that
if
> we were to race a relational system and an IMS hierarchical system with
> *exactly* the same resources in terms of memory, processing power,
platform
> characteristics, I/O capabilities, secondary storage, and inter-process
> communication overhead (which is probably not really possible), over fixed
> data access paths which correspond to how the hierarchy is formed in IMS,
> the IMS system would be and is faster (sub-second responses).
>
> Laconic2 can correct me if this is not what he meant.

You caught what I meant, but what you said is clearer than what I was thinking. Thanks.

Decades, ago, I saw some benchmarks between VAX DBMS and VAX Rdb/VMS. VAX DBMS won all the benchmarks.
But God help you if the schema evolved in any way at all with VAX DBMS. On the other hand, adding or dropping indexes in Rdb was as easy as playing a video game. And adding new tables, or altering domains of existing columns was easy as well. So you could cope with database mission creep, provided you knew some other things (long topic).

With VAX DBMS, you were locked into a long cycle between major revisions of the schema.

Your comments regarding IMS are more to the point than what I just said. Received on Tue Nov 09 2004 - 13:45:37 CET