4 ms·

In the 1980s or 90s, Jim Gray predicted that in the far future memory hierarchy would be reduced to main memory + tape. Not sure that prediction holds up (alth

In the 1980s or 90s, Jim Gray predicted that in the far future memory hierarchy would be reduced to main memory + tape. Not sure that prediction holds up (although streaming dbs in the cloud seem awfully "tape-like" to me?), but I did attempt to quickly redo his "5 minute rule" calculations: https://news.ycombinator.com/item?id=42125052 https://news.ycombinator.com/item?id=42125052 If I did the math right, there's no point to swap or paging anymore, as the break-even point I got was evict after 1 week* (instead of 5 min) for random access patterns, and evict after 5 hours for sequential access patterns. These days maybe those breakeven calculations would be more useful for deciding how long to keep something in a register and when it'd be better to recalculate or spill to main memory? * of course, if you keep everything in main memory and forget nothing, we're close to what in 1998 was one of McCarthy's pipe dreams: Elephant2000 http://www-formal.stanford.edu/jmc/elephant/elephant.html http://www-formal.stanford.edu/jmc/elephant/elephant.html ; I guess if I were to attempt something like Elephant2038, it'd wind up looking like a bunch of past-oriented LTL formulae? (the "speech acts" were probably Winograd's influence?)

gradschoolfail 2y ago
Not to needlessly alleviate your suffering, but what is LTL? Of course, these Nobel Bauble driven days, “quantum memories” sound like little more than search engine bawdlerised AdWords..
- 082349872349872 2y ago
  Linear Temporal Logic: https://www.cs.colostate.edu/~france/CS614/Slides/Ch5-Summary.pdf https://www.cs.colostate.edu/~france/CS614/Slides/Ch5-Summar... (for Xφ, I prefer to define it as relative to a given frame: φ holds the next time any of the frame variables change, which allows both continuous<->discrete translation and for Lamport's stuttering [to allow abstraction!]) Next up: GC via creation and annihilation operators? (in my algebraic view of informatics, one is often either structuring by cleaving two parts to make a whole, or destructuring by cleaving a whole into two parts) EDIT: and by past-oriented I mean using "was ever" for "eventually" and in the past for "globally", as well as "since" for "until". rotate t by i^2. Eg dirty := F{edit} U ({save} ∨ {load}) says the local buffer differs from the cloud if there was ever an edit since a save or load. EDIT 2: ...and I'm pretty sure I can autogenerate code that turns these kinds of def'ns into an imperative event-driven state machine; one can of course come up in theory with formulae that require an arbitrarily complex implementation, but I think in practice most def'ns (especially if we provide backpressure by signalling the complexity of the resulting imp) would be satisfied with simple ones.
  - gradschoolfail 2y ago
    Thanks for the ref! Not sure when i’ll get there praying for a serendipitous intersection of cargoculting nonsssociativity and diagram spelunking (aided by your hints, half-remember’d) Although… i confess to doing the trivial thing of drawing the “cayley graph” of {rock,paper,scissors} and observing that it looks like a loopfree 3-vertex term (1 outgoing) https://en.wikipedia.com/wiki/Commutative_magma https://en.wikipedia.com/wiki/Commutative_magma
    - 082349872349872 2y ago
      Rock-paper-scissors also gives rise to scenes that are bad for naive sorting (for graphics or CAD), where you have three objects such that any two can be sorted in occlusion order, but not all three. Can we triage our ikigai such that I (sympathising with my machinery) take all your overly-associative structures and you (communing with the universe?) take all my insufficiently-associative structures? (there are many in maths: eg topologies, being families of sets, can be represented by a particular magma) Lagniappe: https://www.georgehart.com/triad.html https://www.georgehart.com/triad.html
      - gsf_emergency 2y ago
        Well ring me when you've a way of categorizing some of the nonrepresentable topologies, I do love any chance to juxtapose those ikigais https://news.ycombinator.com/item?id=42106477 https://news.ycombinator.com/item?id=42106477
        082349872349872 2y ago
        Categorically, while different algebraic structures may not be isomorphic, they're likely all capable (under decoration) of carrying the same information. For instance, in the Boom Hierarchy* (sets,bags,lists,trees) we can represent the information carried by any of the structures by any of the others (exercise!) despite the fact that operations on that information may be made easier or more difficult by the presence or lack of laws (idempotency,commutativity,associativity) that are the linear delta-edges between those types-as-vertices themselves. [IIRC, magmas would be mobiles, and I'd bet we can extend the above to them as well.] * I know I repeat these often, but hey, I'm not alone: gopher-the-language was inspired by a "go" lemma-function in someone's sol'n to samefringe.

gradschoolfail 2y ago

Not to needlessly alleviate your suffering, but what is LTL? Of course, these Nobel Bauble driven days, “quantum memories” sound like little more than search engine bawdlerised AdWords..

082349872349872 2y ago
Linear Temporal Logic: https://www.cs.colostate.edu/~france/CS614/Slides/Ch5-Summary.pdf https://www.cs.colostate.edu/~france/CS614/Slides/Ch5-Summar... (for Xφ, I prefer to define it as relative to a given frame: φ holds the next time any of the frame variables change, which allows both continuous<->discrete translation and for Lamport's stuttering [to allow abstraction!]) Next up: GC via creation and annihilation operators? (in my algebraic view of informatics, one is often either structuring by cleaving two parts to make a whole, or destructuring by cleaving a whole into two parts) EDIT: and by past-oriented I mean using "was ever" for "eventually" and in the past for "globally", as well as "since" for "until". rotate t by i^2. Eg dirty := F{edit} U ({save} ∨ {load}) says the local buffer differs from the cloud if there was ever an edit since a save or load. EDIT 2: ...and I'm pretty sure I can autogenerate code that turns these kinds of def'ns into an imperative event-driven state machine; one can of course come up in theory with formulae that require an arbitrarily complex implementation, but I think in practice most def'ns (especially if we provide backpressure by signalling the complexity of the resulting imp) would be satisfied with simple ones.
- gradschoolfail 2y ago
  Thanks for the ref! Not sure when i’ll get there praying for a serendipitous intersection of cargoculting nonsssociativity and diagram spelunking (aided by your hints, half-remember’d) Although… i confess to doing the trivial thing of drawing the “cayley graph” of {rock,paper,scissors} and observing that it looks like a loopfree 3-vertex term (1 outgoing) https://en.wikipedia.com/wiki/Commutative_magma https://en.wikipedia.com/wiki/Commutative_magma
  - 082349872349872 2y ago
    Rock-paper-scissors also gives rise to scenes that are bad for naive sorting (for graphics or CAD), where you have three objects such that any two can be sorted in occlusion order, but not all three. Can we triage our ikigai such that I (sympathising with my machinery) take all your overly-associative structures and you (communing with the universe?) take all my insufficiently-associative structures? (there are many in maths: eg topologies, being families of sets, can be represented by a particular magma) Lagniappe: https://www.georgehart.com/triad.html https://www.georgehart.com/triad.html
    - gsf_emergency 2y ago
      Well ring me when you've a way of categorizing some of the nonrepresentable topologies, I do love any chance to juxtapose those ikigais https://news.ycombinator.com/item?id=42106477 https://news.ycombinator.com/item?id=42106477
      - 082349872349872 2y ago
        Categorically, while different algebraic structures may not be isomorphic, they're likely all capable (under decoration) of carrying the same information. For instance, in the Boom Hierarchy* (sets,bags,lists,trees) we can represent the information carried by any of the structures by any of the others (exercise!) despite the fact that operations on that information may be made easier or more difficult by the presence or lack of laws (idempotency,commutativity,associativity) that are the linear delta-edges between those types-as-vertices themselves. [IIRC, magmas would be mobiles, and I'd bet we can extend the above to them as well.] * I know I repeat these often, but hey, I'm not alone: gopher-the-language was inspired by a "go" lemma-function in someone's sol'n to samefringe.