This page is a quick reference checkpoint for CUME_DIST in MySQL: behavior, syntax rules, edge cases, and a minimal example; plus the official vendor documentation.
CUME_DIST returns the cumulative distribution, showing the proportion of rows with values less than or equal to the current row.
Returns the fraction of rows with values less than or equal to the current row; result is between 0 and 1.
If this behavior feels unintuitive, the tutorial below explains the underlying pattern step-by-step.
CUME_DIST() must be used with an OVER clause and computes the cumulative distribution of a row within its partition.
SELECT CUME_DIST() OVER (ORDER BY salary) AS cume_dist 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.
CUME_DIST is part of a bigger window-function pattern. If you want the “why”, start here: Percentile Distribution
Reading docs is useful. Writing the query correctly under pressure is the skill.
For the authoritative spec, use the vendor docs. This page is the fast “sanity check”.
View MySQL Documentation →Looking for more functions across all SQL dialects? Visit the full SQL Dialects & Window Functions Documentation.