From: Kevin Dick Subject: Re: Relationals vs. Objects Databases I Date: 1998/02/02 Message-ID: <34D63AE1.9691C1D8@dick.org>#1/1 Content-Transfer-Encoding: 7bit References: <01bd230c$6c367590$ec0bbac3@m3bj1> <6b43mv$kg0$1@wnnews1.netlink.net.nz> Content-Type: text/plain; charset=us-ascii Organization: scruz-net Mime-Version: 1.0 Newsgroups: cern.oracle,comp.databases.object,comp.databases.objects,comp.databases.theory Andrew McClure wrote: > > I have been following this thread with some interest, and being relatively > new to Object Databases, I won't fly into the current debate, however - > I have one simple question. If one was to take a variety of running > RDBMS applications, and port them to an ODBMS on similar hardware - > Is there a rule of thumb that would predicate the performance > difference, would it favour ODBMS, and if so, by how much. > > Further to this, if one did the same for RDBMS systems enhanced with, > and using Object extensions, would these results differ dramatically? The performance improvement would depend a lot on the data model and access pattern of the application. Application data models with lots of relationships between elements and a traversal access pattern would experience a significant performance increase from a switch to an ODBMS. From benchmark results and anecdotal evidence, this improvement ranges from 1 to 3 orders of magnitude decrease in response time. What is "lots of relationships"? Hard to say, but if you have an E-R diagram where most of the arcs cross more than one other arc, that's a pretty good indication. It's much harder to say for ORDBMS because their support for object features differs significantly. In most cases, the underlying storage is still tables so the improvement for relationship traversal should be modest, perhaps a factor of 2 decrease in response time at best. However, if the issue is complex datatypes, the results will be much better. In most cases, ORDBMS extend the datatype capabilities quite a bit. Storing and manipulating ADTs and multimedia types could yield an order of magnitude or more improvement. Kevin