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Posted to dev@calcite.apache.org by 张帅 <79...@gmail.com> on 2022/10/24 01:39:02 UTC

apache calcite UDAF implementation

hi,
I am implementing a user-defined aggregate function, it needs input two
parameters like "AGG(column, 5)", the first is the agg column, the second
is
a number literal.
I implement it like this:
public class CalciteUDAF {
         public List init() {return new ArrayList()}
         public List add(List accumulator, Object o) {*accumulator.add(o)*}
         public Object result(List accumulator) {return xxxx}
}

I use schemaPlus.add("AGG",
AggregateFunctionImpl.create(CalciteUDAF.class)) to use it.

but how could I use the second parameter in this UDAF? could anyone give me
some advice?

Re: apache calcite UDAF implementation

Posted by 张帅 <79...@gmail.com>.

get it, in add

张帅 <79...@gmail.com> 于2022年10月24日周一 09:39写道：

> hi,
> I am implementing a user-defined aggregate function, it needs input two
> parameters like "AGG(column, 5)", the first is the agg column, the second
> is
> a number literal.
> I implement it like this:
> public class CalciteUDAF {
>          public List init() {return new ArrayList()}
>          public List add(List accumulator, Object o) {*accumulator.add(o)*
> }
>          public Object result(List accumulator) {return xxxx}
> }
>
> I use schemaPlus.add("AGG",
> AggregateFunctionImpl.create(CalciteUDAF.class)) to use it.
>
> but how could I use the second parameter in this UDAF? could anyone give
> me some advice?
>