Query for Calculating Running Totals with Window Functions in

Query to Calculate Running Totals Using Window Functions in PostgreSQL

-- Query to calculate running totals using window functions in PostgreSQL

WITH running_totals_cte AS (
    SELECT
        column1,
        column2,
        column3,
        SUM(column4) OVER (ORDER BY column1) AS running_total
    FROM
        your_table_name
)
SELECT
    column1,
    column2,
    column3,
    running_total
FROM
    running_totals_cte;

Explanation and Annotations:

1. CTE (Common Table Expression):

   • Utilized to create a temporary result set named running_totals_cte for calculating running totals efficiently.

2. Window Function:

   • The SUM(column4) OVER (ORDER BY column1) calculates the running total of column4 partitioned by the values in column1.

3. Optimization:

   • Window functions are optimized in PostgreSQL for performing calculations efficiently on large datasets.

4. Final Output:

   • The final SELECT statement retrieves the original columns along with the calculated running total from the CTE.

By leveraging window functions within a Common Table Expression, this query efficiently calculates running totals for a complex dataset stored in a PostgreSQL database with millions of records.