Package org.apache.flink.table.runtime.operators.join.stream.keyselector

Interface JoinKeyExtractor

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      org.apache.flink.table.data.RowData getCommonJoinKey​(org.apache.flink.table.data.RowData row, int inputId)
      Extracts the common key from an input row.
      int[] getCommonJoinKeyIndices​(int inputId)
      Gets the field indices in the source row that make up the common join key for a given input.
      org.apache.flink.table.types.logical.RowType getCommonJoinKeyType()
      Gets the type information for the common join key.
      org.apache.flink.table.data.RowData getJoinKey​(org.apache.flink.table.data.RowData row, int inputId)
      Extracts the key used for storing the input record in its corresponding state view.
      int[] getJoinKeyIndices​(int inputId)
      Gets the field indices in the source row that make up the join key for a given input.
      org.apache.flink.table.types.logical.RowType getJoinKeyType​(int inputId)
      Returns the type of the join key for a given input.
      org.apache.flink.table.data.RowData getLeftSideJoinKey​(int depth, org.apache.flink.table.data.RowData joinedRowData)
      Extracts the key used for looking up matching records in the state of a specific input depth, based on the rows accumulated from previous inputs.
      void requiresKeyDeepCopy()
      Enables copying of row data.

    • Method Detail

      • getJoinKey

        org.apache.flink.table.data.RowData getJoinKey​(org.apache.flink.table.data.RowData row,
                                               int inputId)
        Extracts the key used for storing the input record in its corresponding state view.

        This key determines how records from a specific input stream are organized within their state.

        Parameters:
        row - The input row for which to extract the storage key.
        inputId - The ID (0-based index) of the input stream this row belongs to.
        Returns:
        A RowData representing the state storage key. Can be null if no key can be derived (e.g., missing configuration).

      • getLeftSideJoinKey

        org.apache.flink.table.data.RowData getLeftSideJoinKey​(int depth,
                                                       org.apache.flink.table.data.RowData joinedRowData)
        Extracts the key used for looking up matching records in the state of a specific input depth, based on the rows accumulated from previous inputs.

        When processing the join recursively at a certain `depth`, this key is used to query the state associated with that `depth` (i.e., the state for input `depth`) to find potential join partners.

        Parameters:
        depth - The current processing depth (0-based index), representing the target input ID for state lookup.
        joinedRowData - JoinedRowData with rows accumulated so far in the current recursive join path.
        Returns:
        A RowData representing the state lookup key. Can be null if no key can be derived (e.g., missing configuration, or a required row in `joinedRowData` is null).

      • getJoinKeyType

        @Nullable
org.apache.flink.table.types.logical.RowType getJoinKeyType​(int inputId)
        Returns the type of the join key for a given input.
        Parameters:
        inputId - The ID of the input stream.
        Returns:
        The RowType of the join key.

      • getJoinKeyIndices

        int[] getJoinKeyIndices​(int inputId)
        Gets the field indices in the source row that make up the join key for a given input.
        Parameters:
        inputId - The ID of the input stream.
        Returns:
        An array of integers representing the field indices in the source row that form the join key.

      • getCommonJoinKey

        org.apache.flink.table.data.RowData getCommonJoinKey​(org.apache.flink.table.data.RowData row,
                                                     int inputId)
        Extracts the common key from an input row. The common key consists of attributes that are part of all equi-join conditions in the multi-join sequence.
        Parameters:
        row - The input row.
        inputId - The ID of the input stream this row belongs to.
        Returns:
        A RowData representing the common key, or a default key if no common attributes exist or cannot be determined for this input.

      • getCommonJoinKeyType

        org.apache.flink.table.types.logical.RowType getCommonJoinKeyType()
        Gets the type information for the common join key.
        Returns:
        The RowType for the common key join type.

      • getCommonJoinKeyIndices

        int[] getCommonJoinKeyIndices​(int inputId)
        Gets the field indices in the source row that make up the common join key for a given input.
        Parameters:
        inputId - The ID of the input stream.
        Returns:
        An array of integers representing the field indices in the source row that form the common join key.

      • requiresKeyDeepCopy

        void requiresKeyDeepCopy()
        Enables copying of row data.