code: func (e *RadixHashJoinExec) partitionInnerAndBuildHashTables(ctx context.Context) {
  	if err := e.fetchInnerRows(ctx); err != nil {
  		e.innerFinished <- err
  		return
  	}
  
  	if err := e.partitionInnerRows(); err != nil {
  		e.innerFinished <- err
  		return
  	}
  	if err := e.buildHashTable4Partitions(); err != nil {
  		e.innerFinished <- err
  	}
  }
docs: // partitionInnerAndBuildHashTables fetches all the inner rows into memory,
  // partition them into sub-relations, and build individual hash tables for every
  // sub-relations.