/bigquery-cost-check

description: "Audit a BigQuery SQL query or dbt model for potential cost traps before it hits production."
argument-hint: "<sql_file_or_dbt_model>"

BigQuery Cost Check Command

CRITICAL BEHAVIORAL RULES

1. **Analyze Static SQL**: You cannot run the query to see the bytes billed. You must statically analyze the SQL syntax and dbt `config()` blocks. 2. **Focus on Bytes Billed**: In BigQuery, cost is driven by data scanned, not compute time. Focus entirely on reducing data scanned.

Execution Steps

1. Read the provided SQL or dbt model file. 2. Look for the target table's schema (if available in the repo) to identify partitioned columns. 3. Evaluate the `WHERE` clauses. Are partition keys used? If not, flag a full table scan. 4. Evaluate the `SELECT` clauses. Are there unnecessary columns? 5. For dbt models, check the `config` block. Is this a table, view, or incremental model? If it's a massive daily table rebuild, recommend an incremental strategy. 6. Provide a concise report:

• **Risk Level**: (Low, Medium, High)
• **Cost Drivers**: (The specific lines or patterns driving cost)
• **Recommendations**: (Specific SQL or config changes to implement)