Databases · Senior · Question 8 of 75
Why can too many indexes hurt a write-heavy table beyond disk space?
- ✓Correct answer: Every insert or update must modify each index (write amplification), increasing WAL volume, I/O and replication lag
- 2PostgreSQL rejects writes when a table has more than five indexes
- 3Indexes make transactions non-atomic
Explanation
Updates that touch an indexed column also lose the HOT optimization. Drop unused indexes found via pg_stat_user_indexes.