@@ -297,7 +297,7 @@ optionally implemented. While some of these methods allow the system more effici
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@@ -297,7 +297,7 @@ optionally implemented. While some of these methods allow the system more effici
-`merge()` is required for many batch aggreagtions and session window aggregations.
-`merge()` is required for many batch aggreagtions and session window aggregations.
-`resetAccumulator()` is required for many batch aggregations.
-`resetAccumulator()` is required for many batch aggregations.
All methods of `AggregateFunction` must be declared as `public`, not `static` and named exactly as the names mentioned above. The methods `createAccumulator`, `getValue`, `getResultType`, and `getAccumulatorType` are defined in the `AggregateFunction` abstract class, while others are contracted methods. In order to define a table function, one has to extend the base class `org.apache.flink.table.functions.AggregateFunction` and implement one (or more) `accumulate` methods. The method `accumulate` can be overloaded with different custom types and arguments and also support variable arguments.
All methods of `AggregateFunction` must be declared as `public`, not `static` and named exactly as the names mentioned above. The methods `createAccumulator`, `getValue`, `getResultType`, and `getAccumulatorType` are defined in the `AggregateFunction` abstract class, while others are contracted methods. In order to define a aggregate function, one has to extend the base class `org.apache.flink.table.functions.AggregateFunction` and implement one (or more) `accumulate` methods. The method `accumulate` can be overloaded with different parameter types and supports variable arguments.
Detailed documentation for all methods of `AggregateFunction` is given below.
Detailed documentation for all methods of `AggregateFunction` is given below.