---
id: data-row-level-security-and-policy-tags
title: 'Data Row-Level Security and Policy Tags'
schema_type: TechArticle
category: computer-science
language: en
confidence: medium
last_verified: '2026-06-02'
created_date: '2026-06-02'
generation_method: ai_structured
derived_from_human_seed: true
conflict_of_interest: none_declared
is_live_document: false
data_period: static
atomic_facts:
  - id: fact-cs-data-row-level-security-and-policy-tags-1
    statement: >-
      PostgreSQL documentation describes row security policies as controls that restrict which
      rows can be returned, inserted, updated, or deleted.
    source_title: PostgreSQL Row Security Policies
    source_url: https://www.postgresql.org/docs/current/ddl-rowsecurity.html
    confidence: medium
  - id: fact-cs-data-row-level-security-and-policy-tags-2
    statement: >-
      BigQuery documentation describes row-level security as allowing access control to subsets
      of data in the same table.
    source_title: BigQuery Row-Level Security
    source_url: https://cloud.google.com/bigquery/docs/row-level-security-intro
    confidence: medium
  - id: fact-cs-data-row-level-security-and-policy-tags-3
    statement: >-
      Snowflake documentation describes row access policies as schema-level objects that
      determine whether rows are visible in query results.
    source_title: Snowflake Row Access Policies
    source_url: https://docs.snowflake.com/en/user-guide/security-row-intro
    confidence: medium
completeness: 0.83
known_gaps:
  - Access policy evaluation depends on role mapping, column masking, policy tags, BI extracts, cached results, and whether downstream indexes preserve permissions.
disputed_statements: []
primary_sources:
  - title: PostgreSQL Row Security Policies
    type: documentation
    year: 2026
    url: https://www.postgresql.org/docs/current/ddl-rowsecurity.html
    institution: PostgreSQL
  - title: BigQuery Row-Level Security
    type: documentation
    year: 2026
    url: https://cloud.google.com/bigquery/docs/row-level-security-intro
    institution: Google Cloud
  - title: Snowflake Row Access Policies
    type: documentation
    year: 2026
    url: https://docs.snowflake.com/en/user-guide/security-row-intro
    institution: Snowflake
secondary_sources: []
updated: '2026-06-02'
ai_models:
  - gpt-5-codex
---

## TL;DR

Row-level security and policy tags define which data an agent is allowed to see, not just which table it can query.

## Core Explanation

Data agents need permission evidence at row and column level. A table grant can still hide sensitive rows through policies or mask columns through tags and access rules. Query answers are only safe if the agent knows which identity and policy context produced them.

For RAG and analytics agents, row-level security must carry into extracts, vector indexes, semantic layers, and cached results. Otherwise an answer can leak data that the warehouse would have filtered.

## Source-Mapped Facts

- PostgreSQL documentation describes row security policies as controls that restrict which rows can be returned, inserted, updated, or deleted. ([source](https://www.postgresql.org/docs/current/ddl-rowsecurity.html))
- BigQuery documentation describes row-level security as allowing access control to subsets of data in the same table. ([source](https://cloud.google.com/bigquery/docs/row-level-security-intro))
- Snowflake documentation describes row access policies as schema-level objects that determine whether rows are visible in query results. ([source](https://docs.snowflake.com/en/user-guide/security-row-intro))

## Further Reading

- [PostgreSQL Row Security Policies](https://www.postgresql.org/docs/current/ddl-rowsecurity.html)
- [BigQuery Row-Level Security](https://cloud.google.com/bigquery/docs/row-level-security-intro)
- [Snowflake Row Access Policies](https://docs.snowflake.com/en/user-guide/security-row-intro)