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https://issues.apache.org/jira/browse/SPARK-23911?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Xiao Li updated SPARK-23911:
----------------------------
Description:
Ref: https://prestodb.io/docs/current/functions/array.html
Returns a single value reduced from array. inputFunction will be invoked for
each element in array in order. In addition to taking the element,
inputFunction takes the current state, initially initialState, and returns the
new state. outputFunction will be invoked to turn the final state into the
result value. It may be the identity function (i -> i).
{noformat}
SELECT aggregate(ARRAY [], 0, (s, x) -> s + x, s -> s); -- 0
SELECT aggregate(ARRAY [5, 20, 50], 0, (s, x) -> s + x, s -> s); -- 75
SELECT aggregate(ARRAY [5, 20, NULL, 50], 0, (s, x) -> s + x, s -> s); -- NULL
SELECT aggregate(ARRAY [5, 20, NULL, 50], 0, (s, x) -> s + COALESCE(x, 0), s ->
s); -- 75
SELECT aggregate(ARRAY [5, 20, NULL, 50], 0, (s, x) -> IF(x IS NULL, s, s + x),
s -> s); -- 75
SELECT aggregate(ARRAY [2147483647, 1], CAST (0 AS BIGINT), (s, x) -> s + x, s
-> s); -- 2147483648
SELECT aggregate(ARRAY [5, 6, 10, 20], -- calculates arithmetic average: 10.25
CAST(ROW(0.0, 0) AS ROW(sum DOUBLE, count INTEGER)),
(s, x) -> CAST(ROW(x + s.sum, s.count + 1) AS ROW(sum DOUBLE,
count INTEGER)),
s -> IF(s.count = 0, NULL, s.sum / s.count));
{noformat}
was:
Ref: https://prestodb.io/docs/current/functions/array.html
Returns a single value reduced from array. inputFunction will be invoked for
each element in array in order. In addition to taking the element,
inputFunction takes the current state, initially initialState, and returns the
new state. outputFunction will be invoked to turn the final state into the
result value. It may be the identity function (i -> i).
{noformat}
SELECT reduce(ARRAY [], 0, (s, x) -> s + x, s -> s); -- 0
SELECT reduce(ARRAY [5, 20, 50], 0, (s, x) -> s + x, s -> s); -- 75
SELECT reduce(ARRAY [5, 20, NULL, 50], 0, (s, x) -> s + x, s -> s); -- NULL
SELECT reduce(ARRAY [5, 20, NULL, 50], 0, (s, x) -> s + COALESCE(x, 0), s ->
s); -- 75
SELECT reduce(ARRAY [5, 20, NULL, 50], 0, (s, x) -> IF(x IS NULL, s, s + x), s
-> s); -- 75
SELECT reduce(ARRAY [2147483647, 1], CAST (0 AS BIGINT), (s, x) -> s + x, s ->
s); -- 2147483648
SELECT reduce(ARRAY [5, 6, 10, 20], -- calculates arithmetic average: 10.25
CAST(ROW(0.0, 0) AS ROW(sum DOUBLE, count INTEGER)),
(s, x) -> CAST(ROW(x + s.sum, s.count + 1) AS ROW(sum DOUBLE,
count INTEGER)),
s -> IF(s.count = 0, NULL, s.sum / s.count));
{noformat}
> High-order function: aggregate(array<T>, initialState S, inputFunction<S, T,
> S>, outputFunction<S, R>) → R
> ----------------------------------------------------------------------------------------------------------
>
> Key: SPARK-23911
> URL: https://issues.apache.org/jira/browse/SPARK-23911
> Project: Spark
> Issue Type: Sub-task
> Components: SQL
> Affects Versions: 2.3.0
> Reporter: Xiao Li
> Assignee: Herman van Hovell
> Priority: Major
>
> Ref: https://prestodb.io/docs/current/functions/array.html
> Returns a single value reduced from array. inputFunction will be invoked for
> each element in array in order. In addition to taking the element,
> inputFunction takes the current state, initially initialState, and returns
> the new state. outputFunction will be invoked to turn the final state into
> the result value. It may be the identity function (i -> i).
> {noformat}
> SELECT aggregate(ARRAY [], 0, (s, x) -> s + x, s -> s); -- 0
> SELECT aggregate(ARRAY [5, 20, 50], 0, (s, x) -> s + x, s -> s); -- 75
> SELECT aggregate(ARRAY [5, 20, NULL, 50], 0, (s, x) -> s + x, s -> s); -- NULL
> SELECT aggregate(ARRAY [5, 20, NULL, 50], 0, (s, x) -> s + COALESCE(x, 0), s
> -> s); -- 75
> SELECT aggregate(ARRAY [5, 20, NULL, 50], 0, (s, x) -> IF(x IS NULL, s, s +
> x), s -> s); -- 75
> SELECT aggregate(ARRAY [2147483647, 1], CAST (0 AS BIGINT), (s, x) -> s + x,
> s -> s); -- 2147483648
> SELECT aggregate(ARRAY [5, 6, 10, 20], -- calculates arithmetic average: 10.25
> CAST(ROW(0.0, 0) AS ROW(sum DOUBLE, count INTEGER)),
> (s, x) -> CAST(ROW(x + s.sum, s.count + 1) AS ROW(sum DOUBLE,
> count INTEGER)),
> s -> IF(s.count = 0, NULL, s.sum / s.count));
> {noformat}
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