Re: Quote from comp.object

On Feb 28, 10:37 am, Sampo Syreeni <d..._at_iki.fi> wrote:
> [snip] Hence, the RM places little to no constraints on optimization. [snip]

I agree with Sampo's onservations, with one practical caveat.

One principle objective of relational DBMS systems is to separate data management from application code, allowing several applications to share one database. This leads to situations where the DBMS is implemented as one set of (operating system) processes, and the application(s) in another(others).

Most hierarchical systems--IMS, Pick etc -- share with many embedded data managers -- Berkeley DB, etc -- the property that the data management is co-resident with the application code in a single process. By avoiding the cost of moving data between processes, hierarchical data managers adopting this architecture gain considerable response time and throughput advantages.

That said, it doesn't amount to a hill of beans in practice. Business flexibility trumps computer performance every time (so long as performance meets some minimal, usually pretty low-bar, level). Received on Thu Mar 01 2007 - 13:17:54 CST