Data catalog

A data catalog is a searchable inventory of an organization's data assets, tables, dashboards, metrics and files, along with metadata such as descriptions, ownership, sensitivity and how frequently something is used. It answers the basic question: what data do we have, and can I trust it?

Where data lineage shows how data moves and transforms between systems, a catalog focuses on discovery and context at rest: what a given table means, who owns it, and whether it is still actively used. Many catalogs also surface lineage, quality signals and access permissions in one place, blurring the line with adjacent data governance tooling. Catalogs are especially important once an organization has both a data warehouse and a data lake, since assets otherwise get scattered with no central index.

Catalogs matter because undocumented data is effectively unusable at scale: analysts waste time rediscovering what already exists, or worse, use the wrong table without knowing it. The main pitfall is treating cataloging as a one-time documentation project rather than an ongoing discipline; catalogs that aren't kept current through automation or clear ownership decay quickly and lose the trust of the people meant to use them.