Intermediate
Search without melting the database
A second-hand marketplace added a search bar. A third of all reads are now text searches with LIKE queries, and the database is on its knees.
A LIKE '%word%' query scans the whole table: it costs about 25 times a normal read. New listings should appear in search within seconds.
What your design must achieve
- Availability ≥ 99.9 %
- Latency p99 < 250 ms
- Stale reads < 2 %
- Infrastructure cost per month < 6,000 $ bonus