ClickHouse/docs/en/sql-reference/statements/select/all.md

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ALL

ALL Clause

If there are multiple matching rows in the table, then ALL returns all of them. SELECT ALL is identical to SELECT without DISTINCT. If both ALL and DISTINCT specified, exception will be thrown.

ALL can also be specified inside aggregate function with the same effect(noop), for instance:

SELECT sum(ALL number) FROM numbers(10);

equals to

SELECT sum(number) FROM numbers(10);

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