BigQuery Editions vs On Demand
These are some notes on the tradeoffs and best practices between On Demand pricing vs Editions pricing.
sql
BigQuery performance best practice: use semi joins when possible
SQL is an amazing language, it lets you declaratively say what you want, and the engine figures out for you the best way to return it to you. Or should I say, it figures out the best way to return it to you given the information it has and the capabilities of the engine itself.
In this post, we’ll discuss a performance optimization technique for BigQuery (also other advanced enough Enteprise Data Warehouses and databases support SEMI JOINS, but I'll focus on BigQuery since it's the one I use the most these days): using semi joins.
NOT IN and NOT EXISTS don't always produce the same result
IN and EXISTS often produce the same result, but when negated and dealing with NULL values, they behave differently.