Explain EXPLAIN (children 2)
 Set
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 5)
    ExpressionList (children 1)
     Literal Array_[Float64_0, Float64_2] (alias reference_vec)
    ExpressionList (children 3)
     Identifier id
     Identifier vec
     Function L2Distance (children 1)
      ExpressionList (children 2)
       Identifier vec
       Identifier reference_vec
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       TableIdentifier tab_l2_f32
    ExpressionList (children 1)
     OrderByElement (children 1)
      Function L2Distance (children 1)
       ExpressionList (children 2)
        Identifier vec
        Identifier reference_vec
    Literal UInt64_3
