> ## Documentation Index
> Fetch the complete documentation index at: https://docs.conseqa.umran.ca/llms.txt
> Use this file to discover all available pages before exploring further.

# Storage Layouts: Physical Partitioning for Data Objects

> Declare storage partition identity for Conseqa data objects. Partition keys and routing keys are distinct concepts, and the analyzer never infers equivalence between them.

A storage layout describes physical partition identity for one L0 data object. Object identity and storage identity are deliberately separate concepts. A `StorageLayout` is declared under `Model.runtime.storage_layouts`.

<Info>
  V1 admits at most one primary layout per object. A layout implies nothing about database vendor, node count, replication factor, consistency level, or partition capacity.
</Info>

## StorageLayout shape

```yaml theme={null}
runtime:
  storage_layouts:
    <layout_id>:
      object:
        data_model: <data_model_id>
        object: <object_id>
      partition_key:
        - <field_path>
        - ...
```

* `partition_key` is a non-empty list of field paths interpreted against the object's canonical schema.
* Object identity and storage identity are distinct: object identity answers "which logical instance," while the layout answers "into which physical partition."

## Partition key is not a routing key

A partition key and a routing key may reference the same fields without becoming the same concept. They may also deliberately differ:

```yaml theme={null}
# Router key defines execution-affinity domain
Router routing key: channel_id

# StorageLayout key distributes data across partitions
StorageLayout partition_key:
  - channel_id
  - bucket
```

This means all work for one channel shares an execution-affinity domain while the channel's data stays distributed across partitions. Conseqa never infers equivalence between routing-domain identity and storage-partition identity merely because their key expressions coincide.

It is equally valid for object identity and storage identity to differ:

```yaml theme={null}
# Object identity
identity:
  - message_id

# Storage partition key
partition_key:
  - channel_id
  - bucket
```

## Full example

```yaml title="StorageLayout example" theme={null}
runtime:
  storage_layouts:
    layout.messages:
      object:
        data_model: data.chat
        object: obj.message
      partition_key:
        - channel_id
        - bucket
```

## What a layout does NOT imply

* Database vendor or product
* Storage node count or topology
* Replication factor or replica placement
* Consistency level or read routing
* Partition capacity or latency guarantees

These physical and quantitative facts remain outside the Conseqa model.

<Tip>
  For how request routing works, see [Routers and Pools](/runtime/routers-and-pools). For the L0 data model and outbox declarations, see [Data Models and Outboxes](/concepts/data-models-and-outboxes).
</Tip>