[Enhancement] support distinct in analytic functions

[morrySnow]

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Description

create table t(id int, c1 int, c2 double, c3 string) properties('replication_num'='1');

support distinct in analytic functions: count, sum and avg

select c1, c2, avg( distinct c1) over(partition by c2) from t;

Solution

1. remove restirct of distinct in analytic functions
   1.1.

   doris/fe/fe-core/src/main/java/org/apache/doris/nereids/parser/LogicalPlanBuilder.java

   Lines 2140 to 2145 in 5435762

   	if (ctx.windowSpec() != null) {
   	if (isDistinct) {
   	throw new ParseException("DISTINCT not allowed in analytic function: " + functionName, ctx);
   	}
   	return withWindowSpec(ctx.windowSpec(), new Count());
   	}

   
   1.2.

   doris/fe/fe-core/src/main/java/org/apache/doris/nereids/parser/LogicalPlanBuilder.java

   Lines 2155 to 2160 in 5435762

   	if (ctx.windowSpec() != null) {
   	if (isDistinct) {
   	throw new ParseException("DISTINCT not allowed in analytic function: " + functionName, ctx);
   	}
   	return withWindowSpec(ctx.windowSpec(), function);
   	}

2. convert functions to distinct one in ExtractAndNormalizeWindowExpression
   2.1. count(distinct c1) over(partition c2) to multi_distinct_count(c1) over(partition c2)
   2.2. sum(distinct c1) over(partition c2) to multi_distinct_sum(c1) over(partition c2)
   2.3. avg(distinct c1) over(partition c2) to cast(multi_distinct_sum(c1) over(partition c2) as double) / cast(multi_distinct_count(c1) over(partition c2) as double)

Are you willing to submit PR?

• Yes I am willing to submit a PR!

Code of Conduct

• I agree to follow this project's Code of Conduct

[cjj2010]

I want to try 2.1

[morrySnow]

@cjj2010 This issue cannot be split into smaller tasks for solving. Can you handle the entire issue?

[cjj2010]

@cjj2010 This issue cannot be split into smaller tasks for solving. Can you handle the entire issue?

Okay, I am willing to handle the entire issue. The business scenario I am currently facing requires this feature very much

[morrySnow]

@cjj2010 Great! I will assign this issue to you