cache concept
| Definition | A store of recently used data kept so that it need not be fetched again. A cold measurement is taken before the cache holds anything useful, a warm one after. Chapter 13. Also cold, warm. |
|---|---|
| Example | A cache holding 4 of a reader’s 10 entries hits 40 percent of that reader’s reads. |
| Book | Data Mining as Observation, draft 0.2, commit f3914f0; entry id cache, kind concept. |
| Status | no ledger row names this entry. Corrections: none recorded. |
| Defining equation | none |
| Assumptions and scope |
|
| Prior art | none recorded |
| Evidence | lean/DataMiningAsObservation/Cache.lean |
| Reviewed | not yet reviewed; generated 2026-09-10 from records at the commits on the provenance page. |
Equation
none
Conditions
- A store of recently used data kept so that it need not be fetched again. A cache reader reads the entries in its footprint and nothing else, so its hit rate over a stream of requests lies in the unit interval, is zero cold and one warm, never falls when the cache holds more, and is unchanged by entries outside the requests.
- A cold and a warm measurement of the same system are two observers of it. The ZooKeeper substrate’s false-clear rate was 0.99 hot and 0.01 cold, which is the case that a cache’s number is the requests’ number.
Conditions are curated in entries.toml rather than read
from a record.
Ledger
none
First stated
Chapter 13 section 13.5 of Data Mining as Observation, with the cache reader row of chapter 1’s consumer table and the hot-and-cold substrate measurements of the freshness track.
Measurements
none
Failures and corrections
none
Invariance envelope
none declared
Machine checked
lean/DataMiningAsObservation/Cache.lean,
theorems hitRate_mem_unit, hitRate_cold,
hitRate_warm, hitRate_mono,
hitRate_footprint, at observation-data-mining f3914f0; what
the check covers is stated in the book’s appendix
C.
Used in
Data Mining as Observation primers L and S, chapters 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14.
Related
KV cache; eviction; freshness; replica; consumer.
See also
Book equations stated beside the entry’s terms, not defining it: 13.1, 0.26.
Ledger rows that cite the entry’s records without naming it: OT-11, GO-12.
Sources-table rows that share a record with the entry without naming it: chapter 8 section 8.9.
Status
Generated 2026-09-10 by encyclopedia/generate.py; book
at observation-data-mining f3914f0; the commit of every record is listed
in the encyclopedia’s provenance.