The document discusses the challenges of big data including volume, velocity, variety, and veracity. It proposes using PostgreSQL and Hadoop together as a solution, with PostgreSQL serving as a multi-model database server that can handle structured, semi-structured, and unstructured data in relational, object-relational, nested-relational, array, key-value, document, and range formats. Hadoop is described as a distributed file structure that can perform ETL to convert unstructured to structured data for analytics, easily handle unstructured data like logs and streaming data, and enable parallel processing via MapReduce at the petabyte scale. The takeaway is that together, PostgreSQL and Hadoop can solve "most" big