In this article, we reveal the nature and effects of data infrastructures on the authorisation of data that represent students and educational practitioners, including how such data can misrepresent and govern educational policy and practices in sometimes problematic ways. To better understand the governance capacities of data infrastructures, we draw upon notions of discursive practices and materiality, and apply these to a specific school management system, "OneSchool," in Queensland, Australia. We show how data infrastructures both promote and impede educational practitioners' use of data in decision making and daily practices. This includes precluding information about students' (positive) behaviours and omitting important enrolment information about students' Indigenous languages. By doing so, we show how data infrastructures govern in ways that authorise the preclusion and omission of data, thereby representing students and schooling.