tradein-mvp/backend/data/sql/131_fix_diff_percent_overflow.sql

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+-- Migration 131: fix NumericValueOutOfRange crash in record_listing_price_change()
+--
+-- Incident: prod run_id=260, 2026-06-20
+--   A listing scrubbed by avito_full_load had an OLD.price_rub that was
+--   garbage-small (data entry error or placeholder value). The computed
+--   diff_percent = round((NEW-OLD)/OLD*100, 2) exceeded ±999.99, which
+--   overflows numeric(5,2) (precision=5, scale=2, max value=±999.99).
+--   PostgreSQL raised DataError: "numeric field overflow" inside the
+--   trigger, which caused the INSERT into listings to abort, which caused
+--   the entire avito_full_load batch to crash.
+--   The trigger is shared across all non-cian sources → same crash would
+--   occur for yandex/domclick full_load batches on similar data.
+--
+-- Fix (two parts):
+--   1. Widen diff_percent column to numeric(8,2) (max ±999999.99%).
+--      Widening precision is safe and lossless for existing data.
+--   2. Replace the trigger function to clamp the computed value into
+--      [−999999.99, +999999.99] so even future extreme deltas cannot
+--      overflow the column. All other logic is preserved exactly as in
+--      migration 116.
+--
+-- Dependencies: offer_price_history table (023), listings table,
+--   offer_price_history_listing_change_uq unique constraint,
+--   trigger listings_price_change_trg (116).
+--
+-- Idempotent: ALTER TYPE widening is a no-op if already numeric(8,2);
+--   CREATE OR REPLACE FUNCTION is always safe to re-run.
+--   Trigger is NOT recreated — the existing trigger already points to
+--   record_listing_price_change(); replacing the function body is enough.
+--
+-- Deploy order: standalone; auto-applied by deploy pipeline via
+--   _schema_migrations. Do NOT apply manually on prod — causes drift.
+
+BEGIN;
+
+-- Part 1: widen the column.
+-- numeric(5,2) → numeric(8,2): raises max from ±999.99 to ±999999.99.
+-- PostgreSQL widens precision without rewriting rows (catalogue-only change
+-- for heap tables when scale does not decrease and precision does not decrease).
+ALTER TABLE offer_price_history
+    ALTER COLUMN diff_percent TYPE numeric(8,2);
+
+-- Part 2: replace trigger function with clamped diff_percent computation.
+-- All guards from migration 116 are preserved verbatim:
+--   • same-value skip (IS NOT DISTINCT FROM)
+--   • NULL new-price skip
+--   • cian source skip (backfill exclusion — see 116 for rationale)
+--   • OLD.price_rub > 0 gate (avoid division by zero / nonsensical pct)
+--   • ON CONFLICT DO NOTHING (idempotent re-scrape)
+CREATE OR REPLACE FUNCTION record_listing_price_change()
+RETURNS trigger
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    -- Skip if price did not actually change (same-value upsert write).
+    IF NEW.price_rub IS NOT DISTINCT FROM OLD.price_rub THEN
+        RETURN NEW;
+    END IF;
+    -- Skip if the new price is NULL (defensive; price_rub is NOT NULL in practice).
+    IF NEW.price_rub IS NULL THEN
+        RETURN NEW;
+    END IF;
+    -- Skip cian: its history is source-provided via cian_price_history.py backfill.
+    -- That service selects listings WHERE oph.listing_id IS NULL (zero rows in
+    -- offer_price_history). Inserting a trigger row here would permanently
+    -- exclude those listings from the backfill, losing accurate historical timestamps.
+    IF NEW.source = 'cian' THEN
+        RETURN NEW;
+    END IF;
+
+    INSERT INTO offer_price_history (
+        listing_id,
+        change_time,
+        price_rub,
+        source,
+        diff_percent,
+        recorded_at
+    ) VALUES (
+        NEW.id,
+        now(),
+        NEW.price_rub,
+        NEW.source,
+        CASE
+            WHEN OLD.price_rub IS NOT NULL AND OLD.price_rub > 0
+            THEN LEAST(GREATEST(
+                    round(
+                        (NEW.price_rub::numeric - OLD.price_rub::numeric)
+                        / OLD.price_rub::numeric * 100,
+                        2
+                    ),
+                    -999999.99), 999999.99)
+            ELSE NULL
+        END,
+        now()
+    )
+    ON CONFLICT ON CONSTRAINT offer_price_history_listing_change_uq
+    DO NOTHING;
+
+    RETURN NEW;
+END;
+$$;
+
+COMMIT;