Cosmos DB (NoSQL) topics

Cosmos DB in Fabric as AI agent memory: vector search, partitioning, and the OneLake mirror?

jubinsoni — Sat, 03 Oct 2026 00:11:59 GMT

I'm evaluating Cosmos DB in Fabric as the storage layer for an AI agent, for example one built in Microsoft Foundry. It would hold:

Conversation history and session state per user
Long-term memory: facts or summaries the agent extracts, stored with embeddings for retrieval
Agent run logs (tool calls, decisions) that I'd like to analyze in Power BI or KQL

My understanding is that Cosmos DB in Fabric supports vector search and automatically mirrors data to OneLake, so the same data could serve the agent at runtime and support analytics afterward. Before committing, I'd like to understand a few things.

Questions:

Partitioning: for agent memory, is /userId a sensible partition key, or is it better to use hierarchical partition keys (for example /tenantId/userId/sessionId)? Are there hot-partition risks with very active users?
Vector search: what are the practical limits in Cosmos DB in Fabric (embedding dimensions, index types, items per container)? Is hybrid search (vector plus full-text) available here, or only in standalone Azure Cosmos DB?

Cosmos DB in Fabric (native): Replication doesn't restart after capacity pause

Asmita_27 — Thu, 09 Jul 2026 06:13:16 GMT

Hi team,

Using native Cosmos DB in Fabric (built-in auto-mirror, not the Azure mirrored connector). After a capacity pause/resume, new Cosmos writes don't appear in OneLake / Lakehouse.

Observing:
- Replication monitor shows Status "Running", but "Documents replicated" and "Last completed" seem frozen at pre-pause values.
- Fresh writes succeed in Cosmos but mirrored count doesn't move.
- A brand-new Cosmos DB item mirrors fine, so the service works; just unsure how to recover an existing one.

Tried: waiting, new inserts, refreshing, recreating the shortcut.

Would appreciate guidance on:
1. Is a manual step expected after capacity resume for native Cosmos DB? (I don't see a "Resume replication" control.)
2. Recommended way to recover mirroring without recreating the container?

Thanks for any pointers!

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NTolani — Tue, 09 Dec 2025 15:39:55 GMT

Trying to establish connection from power bi to mongo cosmos azure db. I have below inputs

Host: accountname.mongo.cosmos.azure.com

Account name: accountname

Key: Key

We are using power bi gateway server to connect to cloud.

On power bi service able to create mongodb connector and Azure cosmos db for mongo connector they r successfully established.

These r not available in desktop tool, how to consume data or create model from these gateway connection.

If this can't be used, how to establish this connectivity.

Any feedback appreciated.

Assign my database artifact to specific users or share it?

andrl — Tue, 08 Jul 2025 20:01:54 GMT

I cannot assign my database artifact to specific users or share it?

How do I control access to only some users?

jmaldonado — Tue, 08 Jul 2025 20:00:21 GMT

I don’t want to give access to the feature for all users in my organization. How do I control access to only some users?

I cannot toggle the tenant settings to enabled.

GaryHopeMS — Tue, 08 Jul 2025 19:57:51 GMT

I cannot toggle the tenant settings to enabled.

Cosmos DB is not available as an option

andrl — Tue, 08 Jul 2025 19:55:41 GMT

Cosmos DB is not available as an option when I click Fabric->Workspaces->NewItem.