r0 := UnboundTable: alltypes
  a int8
  b int16
  c int32
  d int64
  e float32
  f float64
  g string
  h boolean
  i timestamp
  j date
  k time

r1 := MyRelation
  a int8
  b int16
  c int32
  d int64
  e float32
  f float64
  g string
  h boolean
  i timestamp
  j date
  k time

Selection[r1]
  selections:
    r1
    a2: r1.a