The CTE was `WITH halflives AS (SELECT profile, CASE profile ...)` with no
FROM clause. Postgres rejects it with 42703 (column "profile" does not
exist) on every hourly invocation, so the temporal dimension of the
recommendation engine had never executed once — obsession (14d half-life)
and contextual (7d) never faded.
Rewritten as `WITH halflives(profile, halflife_sec) AS (VALUES ...)`,
half-lives preserved exactly.
One deliberate semantic change: the broken CASE had an `ELSE 30 * 86400`
fallback, so an unrecognised profile would have decayed on a 30-day
half-life. The VALUES join leaves unknown profiles undecayed instead.
Today that is a no-op (only `forgotten`, already excluded by the WHERE),
but a future profile added without a half-life will now conspicuously not
decay rather than quietly decaying at an arbitrary rate.
Verified against a scratch PG16 with one belief per profile aged exactly
one half-life: UPDATE 2, obsession and contextual halved, forgotten and a
fresh longterm untouched. Against the live DB (in a rolled-back
transaction) the fix reports UPDATE 843.
NOTE ON ROLLOUT: the first successful run applies ~23 days of accrued
decay at once, cutting obsession beliefs to ~0.32x. That is correct
behaviour, but recommendations will shift visibly. Expected, not a
regression.
REVIEW-2026-07-30.md finding 3.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
kami
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