Are this host's DB primitives fresh enough to model against?

snapshot_bcfp.sh loads four primitives from public sources into each host's local fwapg. Every cypher reloads them during prep; the dispatcher does not, and nothing checks. On 2026-08-30 the dispatcher's cabd.dams was 2026-05-23 and fresh.modelled_stream_crossings 2026-05-26 — a run started that day would have modelled one bucket on May inputs and three on August inputs, produced one consolidated table set, and said nothing about it anywhere (link#246).

Usage

lnk_preflight_vintage(
  conn = NULL,
  max_age_days = 7,
  tables = .lnk_vintage_primitives(),
  now = Sys.time(),
  vintage = .lnk_vintage_read(conn, tables),
  quiet = FALSE
)

Arguments

conn: A DBI::DBIConnection to the host's local fwapg, or NULL when vintage is supplied directly.
max_age_days: Maximum acceptable age of the oldest primitive.
tables: Fully-qualified table names to check. Defaults to the snapshot-loaded set.
now: Reference time. Injectable so tests are not clock-dependent.
vintage: A data frame with table_name and last_analyze, and optionally table_exists. Defaults to reading conn; pass directly to test, or to judge a stamp collected on another host. Rows in a frame without table_exists are taken to exist.
quiet: Suppress the human-readable report.

Value

Invisibly, a list with ok, vintage, stale, absent, unknown, missing (the union of the last two, kept for callers that only care that something was wrong), oldest_days and message.

Details

The other seven tables in .lnk_input_primitives() are bulk-restored FWA. They are never ANALYZEd, so they carry no vintage at all and are not an axis this can measure — including them would mean every host failing forever on data that is not the staleness risk.

Absence is not a pass, but absence and ignorance are different failures and are reported as such. A table that does not exist is absent; one that exists but yields no usable timestamp is unknown. Both fail, in the same direction as a stale one — a query returning nothing must never read as "nothing is stale" — but they send an operator to different places. Conflating them cost a pilot run, which reported never loaded / absent for a table that was present and healthy.

Two statistics quirks make this fiddlier than it looks. last_analyze alone is unusable: measured across all ten primitives it is NULL on every one and only last_autoanalyze is populated, so the query takes GREATEST of the pair (in Postgres that ignores NULLs and is NULL only when every argument is). And on a freshly restored database neither is set — statistics are collected by (auto)analyze, so a table that was just loaded has rows and no stats at all. The query therefore falls back to the relation file's mtime, which exists for any real table. That fallback is why unknown should be unreachable in practice.

Examples

# Judge a vintage table without touching a database:
now <- as.POSIXct("2026-08-30 12:00:00", tz = "UTC")
v <- data.frame(
  table_name   = link:::.lnk_vintage_primitives(),
  last_analyze = now - c(1, 2, 1, 99) * 86400)
res <- lnk_preflight_vintage(vintage = v, now = now, max_age_days = 7,
                             quiet = TRUE)
res$ok
#> [1] FALSE
res$stale
#> [1] "whse_fish.pscis_assessment_svw"