. Grouping and Filtering
Group data with GROUP BY and filter grouped results with HAVING.
GROUP BY
Choose and apply PostgreSQL GROUP BY patterns to summarize rows into reliable metrics while protecting data quality, storage efficiency, and query performance. Focus: GROUP BY.
HAVING Clause
Choose and apply PostgreSQL HAVING to filter grouped results while protecting data quality, storage efficiency, and query performance. Focus: HAVING Clause.
GROUP BY with ROLLUP / GROUPING SETS
Choose and apply PostgreSQL ROLLUP and GROUPING SETS to produce subtotals and grand totals while protecting data quality, storage efficiency, and query performance. Focus: GROUP BY with ROLLUP / GROUPING SETS.