The playground of SingleStoreDB allows users to run queries over various datasets, including TPC-H, TPC-DS, and a semi-structured game dataset. The playground provides a SQL editor with pre-loaded databases, enabling users to explore and learn best practices for working with JSON data in SingleStoreDB. Key strategies include using Persisted Computed Columns, leveraging the `::` and `$` symbols for parsing out computed columns, and utilizing the Visual Profiler to compare performance of querying whole JSON columns versus persisted computed columns. Users can create views, join tables, output table rows as JSON, build nested JSON objects from columns on their table, perform analytics queries, and more. By mastering these techniques, developers can power JSON-intensive applications at scale with SingleStoreDB.