OVER Clause with PARTITION BY | SQL Server | SQL Tutorial

The OVER clause in SQL Server is used with PARTITION BY to break up the data into partitions​ We can use the OVER clause with functions to calculate the aggregated values such as averages, Count, SUM, running totals, or a top N per group results.​ Partition by in Over clause is used to create a window of rows for a specific result set .​ This Process is called the Windowing of Records. this window is then used in performing different Aggregate Operations.