commercial DDBMSs

Hi! I am a second year MS student in computer science at Texas A&M University. Actually, I need to do some literature survey on the implementation techniques employed in the existing commercially available DDBMSs such as Oracle7, Sybase 10 or older version, Distributed INGRES 6.4, Informix-OnLine 5.0 etc. I saw one posting in the usenet regarding the comparison matrix (by Mr. Drucker). That is really helpful to me. However, I want to know little bit further about the implementation techniques, employed in the above mentioned systems, particularly in the following areas of DDBMSs:- 0. Architecture of the DDBMS from implementation point of view. 1. Concurrency Control 2. Recovery 3. Data Distribution 4. Directory Management and 5. Query optimization I have already done a comrehensive survey of the different algorithms in the above mentioned areas, both for homogeneous DDBMSs and HDDBMSs. I will appreciate any advice and/or help regarding my concern. In particular, sources of the above information, such as, announcements, conference proceedings, manuals etc. I would like to thank the following persons who have already responded to me in this respect:- Donal Daly, Nigel Campbell, Jonathan Leffler, Joe M. Abbate, RW Salnick, Pavan Muzumdar, Devan F. Deway, Elton Wildermuth, Dave Criswell, and Rene Bonvanie. Thanks a lot. sameer (Sameer Soni)