This page is a quick reference checkpoint for FIRST VALUE in IBM DB2: behavior, syntax rules, edge cases, and a minimal example; plus the official vendor documentation.
FIRST_VALUE returns the first value in the window frame.
Returns the value of expr from the first row of the window frame after ORDER BY is applied; frame defaults may cause FIRST_VALUE to reflect the first row of the entire partition unless a frame clause is specified.
If this behavior feels unintuitive, the tutorial below explains the underlying pattern step-by-step.
Requires ORDER BY in the OLAP specification; returns FIRST_VALUE(expr); default window frame determines which row is considered 'first'.
SELECT FIRST_VALUE(salary) OVER (PARTITION BY dept ORDER BY salary) AS first_salary FROM employees
If you came here to confirm syntax, you’re done. If you came here to get better at window functions, choose your next step.
FIRST VALUE is part of a bigger window-function pattern. If you want the “why”, start here: First Last Nth Value
For the authoritative spec, use the vendor docs. This page is the fast “sanity check”.
View IBM DB2 Documentation →Looking for more functions across all SQL dialects? Visit the full SQL Dialects & Window Functions Documentation.