At least in SQL Server CTE's are syntax level, so multiple uses of a CTE in a query causes it to get expanded in each of those places, which typically increases the complexity of the query and can cause issues with the optimizer and performance.
At least in SQL Server CTE's are syntax level, so multiple uses of a CTE in a query causes it to get expanded in each of those places, which typically increases the complexity of the query and can cause issues with the optimizer and performance.