In data storage The
RAID technology may offer two of three desirable values: (relative) inexpensiveness, speed or reliability (
RAID 0 is fast and cheap, but unreliable;
RAID 6 is extremely expensive and reliable, with correct performance and so on). A common phrase in data storage, which is the same in project management, is "fast, cheap, good: choose two". The same saying has been
pastiched in
silent computing as "fast, cheap, quiet: choose two". In researching magnetic recording, used in
hard drive storage, a trilemma arises due to the competing requirements of readability, writeability and stability (known as the Magnetic Recording Trilemma). Reliable data storage means that for very small bit sizes the magnetic medium must be made of a material with a very high
coercivity (ability to maintain its magnetic domains and withstand any undesired external magnetic influences). But this coercivity must be overridden by the drive head when data is written, which means an extremely strong magnetic field in a very tiny space, but the size occupied by one
bit of data eventually becomes so small that the strongest magnetic field able to be created in the space available, is not strong enough to allow data writing...
In anonymous communication protocols Anonymous communication protocols can offer two of the three desirable properties: strong anonymity, low
bandwidth overhead, low
latency overhead. Some anonymous communication protocols offer anonymity at the cost of high bandwidth overhead, that means the number of messages exchanged between the protocol parties is very high. Some offer
anonymity with the expense of latency overhead (there is a high delay between when the message is sent by the sender and when it is received by the receiver). There are protocols which aims to keep the bandwidth overhead and latency overhead low, but they can only provide a weak form of anonymity.
In clustering algorithms Kleinberg demonstrated through an axiomatic approach to clustering that no clustering method can satisfy all three of the following fundamental properties at the same time: •
Scale Invariance: The clustering results remain the same when distances between data points are proportionally scaled. •
Richness: The method can produce any possible partition of the data. •
Consistency: Changes in distances that align with the clustering structure (e.g., making closer points even closer) do not alter the results.
Other (technology) The
CAP theorem, covering guarantees provided by
distributed systems, and
Zooko's triangle concerning naming of participants in
network protocols, are both examples of other trilemmas in technology. == See also ==