code: func (p *Show) ResolveIndices() (err error) {
  	for i, expr := range p.Conditions {
  		p.Conditions[i], err = expr.ResolveIndices(p.schema)
  		if err != nil {
  			return err
  		}
  	}
  	return err
  }
docs: // ResolveIndices implements Plan interface.