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12 Global Databases on High Speed Networks
15 @heading(Noah Mendelsohn)
17 @subheading(IBM T.J. Watson Research Center@*and@*MIT Project Athena)
25 There are few network applications at Athena
27 Network applications are difficult to implement
29 Heterogeneous hardware complicates the problem
31 Synchronization and performance issues are frequently misunderstood
34 @Heading(GDB Approach@*A C Library to Support:)
36 Shared, global relational databases
38 Simplified implementation of servers and clients
40 Explicit support for single process Unix servers
43 @heading(Potential Appplications of GDB)
45 Subject specific databases
49 Cooperative development environments
51 Access to network resources (e.g. videodisc)
53 Interactive game-like environments
55 Discussion systems (conferences)
58 @Heading(GDB Database Services)
60 Full services of RTI Ingres relational databases
62 Available from any GDB client on internet
64 Machine dependencies hidden
66 Synchronous and asynchronous flavors of most services
68 Based on GDB data structuring facilities
71 @Heading(GDB Data Structuring Services)
73 Intended to support GDB's specific needs, @i[not] a generalized
74 extension to C language typing
76 Explicit support for `database types' (e.g. relation, tuple)
78 Representation may vary according to local hardware type
80 Automatic conversion when transmitting between different architectures
85 Limited services for user defined types
88 @Heading(GDB Communication Services)
90 CONNECTIONS: underlying implementation is TCP byte streams, but much
93 Services provided for sending and receiving GDB typed data
95 Queuing for asynchronous operations
97 Synchronization services
99 All services are available to GDB applications
101 Very low latencies can be achieved on suitable networks
103 Asynchronous services can hide network delays from the application
105 GDB @i[database] services are built on top of GDB communication services
108 @Heading(GDB Servers and Clients)
110 @i[Forking] servers are particularly easy to implement
112 @i[Non-forking] servers provide high performance data sharing
114 Limited support for @i[peer-to-peer] communication is also provided
117 @Heading(GDB Project Status)
119 Project started: late winter of 1986
121 A basic, unoptimized, but 95% complete implementation of the specification
122 is now available for Berkeley Unix systems
124 Runs on both RT/PC and Vax machines, should port to others easily
126 Preliminary versions of a User's Guide and a Library Reference Manual
129 A few applications have been built, and several others are under development
131 Several groups and individuals at MIT have expressed interest in the system
134 @Heading(Plans for the Future)
138 Find and support new `customers'
140 Evaluate design, and possibly re-implement some portions based on
143 Enhancements? (e.g. automatic encapsulation of C structures as GDB types)
145 Continue comparisons with other approaches to similar function
146 (integrated distributed databases, RPC, etc.)