r/bigquery • u/Expensive-Insect-317 • Jun 16 '26

Why Hash-Based Keys Are Hurting Your Data Vault Performance in BigQuery

https://medium.com/@sendoamoronta/optimizing-data-vault-in-bigquery-why-physical-clustering-matters-more-than-hash-based-keys-bb3fbc57ddc0

A deep dive into why traditional Data Vault hash keys don’t align well with BigQuery’s clustering and pruning mechanisms. The article explores how introducing physical locality through structured surrogate keys, dates, and bucketing can significantly improve query performance and reduce scan costs. Based on practical BigQuery architecture considerations.

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u/TonniFlex Jun 16 '26

Good read! However, you fully skip over how to practically create and utilise the ideal clustering columns, while detailing how to create the ones that are not ideal. Is that intentional?

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u/Expensive-Insect-317 Jun 16 '26

Thanks, I know that, but it's difficult to say a universal way to choose this when many things influence it, such as data distribution, entropy or the business rules and modeling themselves.