The text discusses the `generateULID` and `ULIDStringToDateTime` functions in ClickHouse, which are used to generate Universally Unique Lexicographically Sortable Identifiers (ULIDs) and extract timestamps from them. ULIDs offer a unique combination of uniqueness, lexicographical sorting, and readability, making them suitable for applications dealing with time-series data. The text also highlights the benefits of using ULIDs over UUIDs, including their ability to be sorted by creation time and being URL-safe. Additionally, it provides examples of how to use these functions effectively, as well as a brief overview of Propel's serverless ClickHouse service, which allows developers to focus on drawing insights from data rather than infrastructure management.