identifier_contract
Identify which key folds merge identifiers and lose data, measuring collision costs and verdicts to distinguish safe from risky normalizations.
Instructions
WHAT ARE THIS STORE'S IDENTIFIERS, and which folds over them would LOSE information?
The question a store outlives its writer to face: someone holds the file months later, the version that wrote it is gone, and whatever deformation happened is already in the bytes. They cannot run a conformance suite. What they need is narrower — which keys are canonical, which folds were DELIBERATE, and which are INVERTIBLE. At remediation time that last distinction is the one that matters: an injective deformation is a backfill job, a fold that maps two keys onto one cannot be undone.
Returns declared (what the running writer promises — byte-exact, case-sensitive, no normalisation)
beside measured (what each candidate fold would actually cost on THIS store's keys, independently
of the claim). Measured on our own decision store: an 8-character prefix fold would merge 594 groups
and lose 1,365 keys, and no field declared any policy at all.
A ZERO COST HAS TWO CAUSES and they render identically, so each fold also carries a verdict.
COST_MEASURED means keys demonstrably merge. NOT_YET_MEASURABLE means the population is too small
for zero to mean anything — 13 UUID keys against an 8-hex-character fold collide with probability
~1e-8, so a zero there is the absence of a signal rather than a clean bill of health. ZERO_AT_SCALE
is the only one that says the fold is harmless on keys like these. Prefix folds also carry
threshold_population (how many more keys before a collision is expected, from the per-position
perplexity of this store's own keys) and collides_at_length / headroom_chars, which need no
model at all: how many characters shorter the fold would have to be before it started merging.
HONEST SCOPE, in limits: declared speaks for the code running now, not for the version that wrote
a record last year; and measured sees only surviving keys, so a fold that ALREADY collapsed two of
them left no trace of the second. Absence of merging is not proof that none occurred.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||