InfluxDB is a high-velocity datastore and query engine designed for time series data at high resolution, meeting business needs for data at nanosecond resolution in various applications such as brain activity tracking, infrastructure monitoring, autonomous vehicle behavior tracking, and stock price changes. To optimize InfluxDB performance, it's essential to use Telegraf for instrumentation, handle retries, modifiable batch sizes, jittering, pre-processing, aggregations, conversions, Line Protocol data format, caching repeat response data, filtering by time and metric/asset/series, and shard durations. Optimizing reads involves using columnar storage, filtering queries with specific columns, and batching functions to reduce memory usage. InfluxDB's underlying file format is columnar, unlike relational databases, which can be optimized for performance through techniques such as EXPLAIN ANALYZE, planning time optimization, and adjusting shard durations to balance read and write performance.