CreateQuery mt (children 3)
 Identifier mt
 Columns definition (children 3)
  ExpressionList (children 2)
   ColumnDeclaration a (children 1)
    DataType UInt64
   ColumnDeclaration b (children 1)
    DataType Nullable (children 1)
     ExpressionList (children 1)
      DataType String
  ExpressionList (children 1)
   Index (children 2)
    Identifier b
    Function set (children 1)
     ExpressionList (children 1)
      Literal UInt64_123
  Function tuple (children 1)
   ExpressionList (children 2)
    Identifier a
    Function coalesce (children 1)
     ExpressionList (children 2)
      Identifier b
      Literal \'test\'
 Storage definition