diff --git a/docs/zh/sql-reference/data-types/simpleaggregatefunction.md b/docs/zh/sql-reference/data-types/simpleaggregatefunction.md index e827adb817e..38d7699c176 100644 --- a/docs/zh/sql-reference/data-types/simpleaggregatefunction.md +++ b/docs/zh/sql-reference/data-types/simpleaggregatefunction.md @@ -1,26 +1,31 @@ ---- -machine_translated: true -machine_translated_rev: 71d72c1f237f4a553fe91ba6c6c633e81a49e35b ---- - # SimpleAggregateFunction {#data-type-simpleaggregatefunction} -`SimpleAggregateFunction(name, types_of_arguments…)` 数据类型存储聚合函数的当前值,而不将其完整状态存储为 [`AggregateFunction`](../../sql-reference/data-types/aggregatefunction.md) 有 此优化可应用于具有以下属性的函数:应用函数的结果 `f` 到行集 `S1 UNION ALL S2` 可以通过应用来获得 `f` 行的部分单独设置,然后再次应用 `f` 到结果: `f(S1 UNION ALL S2) = f(f(S1) UNION ALL f(S2))`. 此属性保证部分聚合结果足以计算组合结果,因此我们不必存储和处理任何额外的数据。 +`SimpleAggregateFunction(name, types_of_arguments…)` 数据类型存储聚合函数的当前值, 并不像 [`AggregateFunction`](../../sql-reference/data-types/aggregatefunction.md) 那样存储其全部状态。这种优化可以应用于具有以下属性函数: 将函数 `f` 应用于行集合 `S1 UNION ALL S2` 的结果,可以通过将 `f` 分别应用于行集合的部分, 然后再将 `f` 应用于结果来获得: `f(S1 UNION ALL S2) = f(f(S1) UNION ALL f(S2))`。 这个属性保证了部分聚合结果足以计算出合并的结果,所以我们不必存储和处理任何额外的数据。 支持以下聚合函数: -- [`any`](../../sql-reference/aggregate-functions/reference.md#agg_function-any) -- [`anyLast`](../../sql-reference/aggregate-functions/reference.md#anylastx) -- [`min`](../../sql-reference/aggregate-functions/reference.md#agg_function-min) -- [`max`](../../sql-reference/aggregate-functions/reference.md#agg_function-max) -- [`sum`](../../sql-reference/aggregate-functions/reference.md#agg_function-sum) -- [`groupBitAnd`](../../sql-reference/aggregate-functions/reference.md#groupbitand) -- [`groupBitOr`](../../sql-reference/aggregate-functions/reference.md#groupbitor) -- [`groupBitXor`](../../sql-reference/aggregate-functions/reference.md#groupbitxor) -- [`groupArrayArray`](../../sql-reference/aggregate-functions/reference.md#agg_function-grouparray) -- [`groupUniqArrayArray`](../../sql-reference/aggregate-functions/reference.md#groupuniqarrayx-groupuniqarraymax-sizex) +- [`any`](../../sql-reference/aggregate-functions/reference/any.md#agg_function-any) +- [`anyLast`](../../sql-reference/aggregate-functions/reference/anylast.md#anylastx) +- [`min`](../../sql-reference/aggregate-functions/reference/min.md#agg_function-min) +- [`max`](../../sql-reference/aggregate-functions/reference/max.md#agg_function-max) +- [`sum`](../../sql-reference/aggregate-functions/reference/sum.md#agg_function-sum) +- [`sumWithOverflow`](../../sql-reference/aggregate-functions/reference/sumwithoverflow.md#sumwithoverflowx) +- [`groupBitAnd`](../../sql-reference/aggregate-functions/reference/groupbitand.md#groupbitand) +- [`groupBitOr`](../../sql-reference/aggregate-functions/reference/groupbitor.md#groupbitor) +- [`groupBitXor`](../../sql-reference/aggregate-functions/reference/groupbitxor.md#groupbitxor) +- [`groupArrayArray`](../../sql-reference/aggregate-functions/reference/grouparray.md#agg_function-grouparray) +- [`groupUniqArrayArray`](../../sql-reference/aggregate-functions/reference/groupuniqarray.md) +- [`sumMap`](../../sql-reference/aggregate-functions/reference/summap.md#agg_functions-summap) +- [`minMap`](../../sql-reference/aggregate-functions/reference/minmap.md#agg_functions-minmap) +- [`maxMap`](../../sql-reference/aggregate-functions/reference/maxmap.md#agg_functions-maxmap) +- [`argMin`](../../sql-reference/aggregate-functions/reference/argmin.md) +- [`argMax`](../../sql-reference/aggregate-functions/reference/argmax.md) -的值 `SimpleAggregateFunction(func, Type)` 看起来和存储方式相同 `Type`,所以你不需要应用函数 `-Merge`/`-State` 后缀。 `SimpleAggregateFunction` 具有比更好的性能 `AggregateFunction` 具有相同的聚合功能。 + +!!! note "注" + `SimpleAggregateFunction(func, Type)` 的值外观和存储方式于 `Type` 相同, 所以你不需要应用带有 `-Merge`/`-State` 后缀的函数。 + + `SimpleAggregateFunction` 的性能优于具有相同聚合函数的 `AggregateFunction` 。 **参数** @@ -30,11 +35,7 @@ machine_translated_rev: 71d72c1f237f4a553fe91ba6c6c633e81a49e35b **示例** ``` sql -CREATE TABLE t -( - column1 SimpleAggregateFunction(sum, UInt64), - column2 SimpleAggregateFunction(any, String) -) ENGINE = ... +CREATE TABLE simple (id UInt64, val SimpleAggregateFunction(sum, Double)) ENGINE=AggregatingMergeTree ORDER BY id; ``` [原始文章](https://clickhouse.tech/docs/en/data_types/simpleaggregatefunction/)