Understanding Future Schema Grants and Permission Gaps

Overview

In Snowflake, generating future grants at the schema level is expected behavior. However, when future grants are defined at both the database and schema levels, a known limitation can lead to permission inconsistencies.

This document explains the cause of the issue and how it is addressed.

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The Snowflake Gap: Database vs. Schema Precedence

There is a known behavior in Snowflake regarding how future grants are evaluated that can disrupt access policies:

🚧 Important Snowflake Behavior When future grants are defined at both the database level and the schema level, the schema-level grants take absolute precedence and the database-level grants are completely ignored.

How the Gap Occurs

1. Database-Level Grant: You grant a privilege (e.g., SELECT ON FUTURE TABLES) to Role A at the Database level. The expectation is that Role A will have access to all future tables across all schemas in that database.

2. Schema-Level Grant: Later, a future grant is applied to Role B at the Schema level for a specific schema within that same database.

3. The Resulting Gap: Because the schema-level grant exists, Snowflake overrides and ignores Role A's database-level grant for that specific schema. When new tables are created in that schema, Role A will receive an "Insufficient Privilege" error, breaking expected data access workflows.

(Reference: Snowflake Knowledge Base - Behavior of future grants when defined at both database and schema level)

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The TrustLogix Solution

TrustLogix eliminates the manual overhead of tracking these precedence conflicts and ensures that your overarching access control policies are respected automatically.

How TrustLogix Fixes This

To fix this Snowflake gap, TrustLogix automates the resolution process for privilege template policies deployed using the TrustLogix Console:

• Targeted Scanning: TrustLogix exclusively scans Privilege template policies that are deployed through the TrustLogix console.

• Automated Grant: If a new policy is deployed at the database level, TrustLogix checks for an existing schema-level policy on the same database. If one is found, TrustLogix automatically adds the specific schema grants to that existing policy to prevent any access gaps.

• Automated Redeployment: If a policy is initially deployed using ALL_SCHEMAS, and subsequently a new policy is created for a selected schema within that same database, TrustLogix automatically redeploys the ALL_SCHEMAS policy. During this redeployment, it appends the additional schema future grants to ensure the broader database-level access intent remains fully intact.

Key Benefits

• Consistent Access: Prevents unexpected "Insufficient Privilege" errors for roles that should inherently have database-wide access.

• Reduced Administrative Overhead: Eliminates the need for Snowflake administrators to manually track overlapping future grants and issue reactive, schema-by-schema permissions.

• Secure Scaling: Allows security and data engineering teams to confidently define broad database policies alongside granular schema policies without breaking data pipelines.