Hi @Karthik_Karanm 

When registering a model that references multiple Unity Catalog tables (backing the vector indexes), Databricks attempts to access and resolve all table metadata during the packaging and validation steps of registration.

Here’s what changes with multiple indexes:

1. Expanded Scope of Access
-- Each Vector Search index is backed by a Delta table in Unity Catalog.
-- Using multiple indexes causes the model registration process to attempt read metadata access across all referenced UC entities.
-- If any of those tables have missing permissions, even temporarily, the registration will fail.

2. Stricter Enforcement in Model Context
-- During interactive development or indexing, you're likely operating under a full-access identity (e.g., your personal workspace or notebook).
-- During model registration, Databricks may execute in a different context (e.g., under the job's service principal or a model registry service identity), which may not have equivalent permissions.