Adventures in null handling: Null money, null problems
Blog post from PostHog
Null values posed challenges during the development of HogQL, a tool providing direct SQL access to data, as they resulted in inaccurate results and customer confusion due to ClickHouse's strict handling of nulls, where any expression containing a null value becomes null. Existing solutions for handling nulls in PostHog were inadequate for HogQL's capabilities, as they required users to manually handle nulls, leading to a cumbersome user experience. To address this, the developers implemented several solutions: modifying how the concat function works to be null-tolerant by converting null values to strings, introducing nullish coalescing to simplify expressions, and adding a nullable property on all fields to enable special null handling without disrupting ClickHouse's optimization processes. These changes improved the user experience by abstracting complex SQL modifications away from users, making direct SQL access more user-friendly while preserving the power and flexibility of HogQL.
No tracked trend matches for this post yet.
Use this post, company, and trend context to find content marketing opportunities, perform competitive analysis, or address product feature gaps via the Plushcap MCP server or the Plushcap API.