mariadb-aggregate-functions

MariaDB aggregate functions — calculations across a set of rows (typically with GROUP BY or as window functions via OVER()). Covers counting (COUNT, COUNT(DISTINCT)), totals/averages (SUM, AVG), extrema (MIN, MAX), string aggregation (GROUP_CONCAT with DISTINCT/ORDER BY/SEPARATOR/LIMIT), bitwise aggregation (BIT_AND, BIT_OR, BIT_XOR), and the statistical family (STD/STDDEV/STDDEV_POP, STDDEV_SAMP, VARIANCE/VAR_POP, VAR_SAMP). Use when summarizing or rolling up rows in MariaDB. Note aggregates skip NULLs, GROUP_CONCAT silently truncates at group_concat_max_len, and ONLY_FULL_GROUP_BY is not in the default sql_mode.