YugabyteDB 2.1 has achieved a 10x performance improvement over the previous release, with optimizations including batch loading data using COPY FROM, parallel execution for full scans and aggregates, index scan improvements, single row update with fine-grained locking, caching checked foreign keys inside transactions, pushing down aggregate functions such as MAX(), and various other enhancements. These optimizations are primarily driven by reducing RPC calls and data transfer over the network, leveraging the reuse of PostgreSQL libraries at both the YSQL query layer and the distributed storage layer called DocDB. YugabyteDB has also shown improved performance in benchmarking results for the Yahoo! Cloud Serving Benchmark (YCSB) and the TPC-C benchmark, with significant gains in throughput and latency across various workloads. The database's geo-distributed design allows it to take network latency into consideration when computing costs, enabling cost-based optimization of queries. With ongoing work on further enhancements such as pushing down entire execution subtrees into DocDB and optimizing GROUP BY queries with pushdowns, YugabyteDB continues to improve its performance and scalability capabilities.