- Ya
- 21 Agosti 2026, 01:36 UTC
- Mwandishi
- Kamo
- Ahadi ya
- 256ac46
Country alone was the only index on an 80,429-row table, and neither real query used it well. Measured on production: city resolution (country + subdivision), US + CA: index-scanned all 18,870 US rows to keep 984 — 138 ms country picker (SELECT DISTINCT country_iso_code, country_name): sequential scan of all 80,429 rows to return 251 — 168 ms (country_iso_code, subdivision1_iso_code) seeks straight to the state's rows; (country_iso_code, country_name) lets the picker resolve without touching the table. Extra indexes are close to free here: this table is replaced wholesale by the weekly GeoLite sync and never written on a request path, so there is no write amplification to trade against.