- What was the first program EDSAC ran on 6 May 1949?
Distributed and Database Systems
Systems that coordinate computation and data across machines.
- What is the stored-program architecture von Neumann designed, and why does it still define modern computers?
- What made EDSAC one of the earliest stored-program computers to be used for genuine scientific work?
- What made ARPANET's packet-switching architecture conceptually different from earlier networks?
- Which universities were connected by the original ARPANET in 1969?
- What is a semaphore, and what problem in process synchronisation did Dijkstra invent it to solve?
- What problem did Charles Bachman's Integrated Data Store (IDS) solve for storing structured data?
- How does a network-model database let programs navigate between records compared to sequential tape access?
- What did Bachman mean by 'The Programmer as Navigator' in his Turing Award lecture?
- How did Bachman's navigable record structures influence the relational databases that came after IDS?
- What problem did Hoare's Communicating Sequential Processes formalism solve for reasoning about concurrent programs?
- How does Codd's relational model differ from the navigational database systems it replaced?
- Why were early implementations of the relational model dismissed as too slow to be useful?
- What role did relational calculus play in giving database engineers a provably correct design target?
- How did SQL databases end up displacing navigational systems that once seemed clearly superior?
- Where do Hopcroft and Tarjan's algorithms show up invisibly in modern computing infrastructure?
- What problem does the Calculus of Communicating Systems (CCS) address in concurrent computing?
- What was the Xerox Alto and why was it significant for personal computing?
- What areas of computing did Butler Lampson's Turing Award citation cover?
- What ideas did Lampson's 1983 paper 'Hints on Computer System Design' put forward?
- What do the ACID properties (Atomicity, Consistency, Isolation, Durability) guarantee about a database transaction?
- Why does a power failure mid-transaction risk leaving a database in a corrupt in-between state without these guarantees?
- How did Jim Gray's work on two-phase commit protocols shape the design of modern database systems?
- How did Liskov's work on Byzantine fault tolerance shape how large distributed systems handle failure?
- How closely did the network the slime mould grew over a map of Tokyo resemble the actual Tokyo rail system?
- Why did the slime mould's growth pattern end up resembling Tokyo's actual rail system?
- What problem do logical clocks solve when computers can't share a perfectly synchronized physical clock?
- What is the Byzantine Generals Problem and why does it define the theoretical limits of consensus?
- How does the Paxos algorithm let distributed systems reach consensus despite failures and delays?
- How did Michael Stonebraker's Ingres project prove that relational databases could run efficiently in practice?
- What did Postgres add to the relational database model that made it useful for scientific data?
- Why is storing data by column rather than row, as C-Store did, faster for analytical queries?
- How does the Message Passing Interface standard let code run across thousands of processors?
- How did Ethernet's collision-detection and backoff protocol let the network manage itself?