Cloud SQL: BigQuery, Redshift, Snowflake

Cloud data warehouses have their own SQL flavors.

BigQuery (Google):

• Uses Standard SQL or Legacy SQL
• UNNEST() for arrays
• Approximate functions (APPROX_COUNT_DISTINCT)
• Nested/repeated fields

Redshift (AWS):

• Based on PostgreSQL
• COPY command for loading
• Distribution styles matter
• No LATERAL joins

Snowflake:

• Very close to ANSI SQL
• FLATTEN() for semi-structured
• QUALIFY clause (filter window functions!)
• Time travel queries

Your core SQL works in all of them!