tp@mccall.uucp (02/23/90)
This is a summary of the responses I received to a couple of questions I posted a little while back. I didn't try to quote anybody, as I don't know if they want things quoted in public. I didn't list all the responses, just a summary. If anyone needs further specific information, let me know. Thanks to everyone who responded. We have decided to use Rdb. In article <2123.25d04079@mccall.uucp> I wrote: >Can anyone give me an idea on the relative performance of VAX Rdb vs. VAX >DBMS vs. straight RMS I/O? We are thinking of using a database product and >don't want to sacrifice too much performance. There is an excellent article on this very topic in the Jan 90 DEC Professional. This is required reading for people in my situation! It discusses Rdb in particular, but most or what is said applies equally to other databases, relational or otherwise. I also got a response from a someone in DEC's database research group, and he said that internal tests have indicated that Rdb READS are as fast as RMS, and that Rdb and DBMS use the same engine and should perform similarly. In article <2120.25d0258f@mccall.uucp> I wrote: >I've read about databases but never used one before. Thus forewarned, could >anyone answer a few questions for me? > >I am writing an application that has to maintain some moderately >complicated data structures on disk and get to them in reasonable amounts >of time. I could do this with indexed files, but it would be easier with a >database, so I'm trying to convince management that I need one. I am >considering Rdb for various reasons. The only info I have on it is the SPD. >1) I think relational would be simpler to use and more flexible in the long >run (I know it will handle this application just fine). General agreement here. >2) We already buy stuff from DEC, so it is easier than searching through >myriad 3rd party vendors. Nobody convinced me otherwise, although several people sent lists of other good products. Nobody gave me a particularly good reason to look at any of them though. [Trivial cost justification thing deleted] >The questions: > >1) Are any of the above reasons faulty? Nobody seemed to think so. >2) Are segmented strings sufficiently general to implement BLOB's (Binary >Large OBjects)? I have some unstructured data that I'd like to stick in the >database for future access. I'd like to have this pointed to by a standard >relation, and for all usual concurrency and integrity controls to apply. Yes. Segmented strings can be of arbitrary size, but you have to break them into 64K segments (a minor annoyance). >3) Is network access to a remote database transparent and fully functional, >or are there restrictions? In particular, I need concurrent local and >remote access, as I do remote support on these applications. Yes, no restrictions. >4) If I write a set of library routines and/or shareable images that access >an Rdb database, to be shared by several applications, do I need the full >development version of Rdb to link against those libraries/images? In other >words, if there is only one system on which development of database access >software would ever be done, but other systems where people would need to >link against the shareable images thus produced, is it sufficient to have >Rdb Runtime Only installed on those other systems. Yes. Full development license is only required to actually write database code. Other developers can use shareable images with Rdb code with the run-time version of Rdb only. The Rdb/VMS Runtime License is included with the VMS license, but you still have to buy the Runtime Kit. >5) Are there any other packages I REALLY should consider? Price is an >issue, but so is application development time. I can't take the time to do >an extensive search, and I can't afford to get something cheaper that would >require more effort to use (as it would increase development time). On the >other hand, if there are packages of equal or better functionality that are >SIGNIFICANTLY cheaper, or packages of equivalent price that are >SIGNIFICANTLY better, I would like to know about them. My development >environment and my target production environment are all LAVC's of >VAXstations. I got various comments on various packages, but nobody gave me a specific reason that any of them had a SIGNIFICANT edge over Rdb except for one response. One responder said that Oracle was about twice as fast in general than Rdb, but much harder to use and administrate, and that the documentation and support were not good. Oracle is also expensive. -- Terry Poot (800)255-2762, in Kansas (913)776-4041 The McCall Pattern Company, 615 McCall Rd., Manhattan, KS 66502, USA UUCP: rutgers!ksuvax1!mccall!tp Internet: tp%mccall@ksuvax1.cis.ksu.edu