What is row-level security in Tableau?

Row-level security (RLS) restricts which rows of data an individual user can see in a published view, so the same dashboard shows different data to different people based on who's logged in — without needing to build a separate workbook per user or team.

User-filter approach:
{ FIXED : IF USERNAME() = [Sales Rep Email] THEN 1 ELSE 0 END } = 1

Or using a mapping table:
[Region] = LOOKUP(current user's allowed region)

• The most common pattern joins or references a permissions/entitlement table mapping usernames (or groups) to the data they're allowed to see.
• A calculated field using USERNAME() or ISMEMBEROF() compares the logged-in user against that entitlement data, and is used as a filter on every relevant worksheet.
• RLS is enforced at query time on Tableau Server/Cloud, based on the identity of whoever is viewing the dashboard.

RLS is essential for any shared dashboard containing sensitive or role-specific data — for example, a regional sales dashboard where each sales manager should only see their own region's numbers, all served from one single published workbook rather than dozens of near-identical copies.