The chunked matcher paged the candidate set with OFFSET over the very predicate
it mutates (building_cadastral_number IS NULL). Matched rows drop out, so OFFSET
(reset to 0 OR advanced) skips un-processed rows: once >= batch_size unmatched
listings (beyond threshold) accumulate at the low-id front, the chunk matches 0
and the loop breaks early, leaving higher-id matchable listings unfilled.
Counterexample (batch=3, matchable ids 1,4,7,10): matches 1 and 4 then breaks,
missing 7 and 10. Unit tests used single-chunk fixtures so never caught it.
The full UPDATE is ~5s for ~41k listings, so replace the loop with ONE set-based
LATERAL KNN UPDATE over all candidates — correct and fast. batch_size kept in the
signature for schedule-param compat (now unused).
bot-backend
f9769571a3