Visualising BigQuery Query Plans

Tldr: visualise BigQuery execution on https://bqvisualiser.appspot.com

BigQuery is a powerful tool to query very large (tera and peta byte scale) data sets using standard SQL. It does so by parallelizing the query into multi sharded workloads, achieving amazing scale and speed.

Yet sometimes queries take longer than imagined. The BigQuery UI gives some support in understanding how the query was executed but it can still be a challenge understanding what happened

I had a customer who runs a complex query with multiple subqueries and joins. The query took hours to complete and we needed to understand what happened. So I…