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

> Contains one row per node of the data tree stored on the local in-process ClickHouse Keeper node.

# system.keeper_storage

<Info>
  **Querying in ClickHouse Cloud**

  The data in this system table is held locally on each node in ClickHouse Cloud. Obtaining a complete view of all data, therefore, requires the `clusterAllReplicas` function. See [here](/docs/reference/system-tables/overview#system-tables-in-clickhouse-cloud) for further details.
</Info>

<h2 id="description">
  Description
</h2>

The table only exists for ClickHouse Keeper deployments that use the `clickhouse server` (and not `clickhouse keeper`) process. It contains one row per node of the data tree stored on the local Keeper node, including the `/keeper` system nodes.

Unlike `system.zookeeper`, this table does not send requests to a Keeper cluster. It reads the committed state of the local Keeper directly from a consistent lock-free view, without affecting request processing. Reading the table does not require a path condition and returns the whole tree, so it is suitable for queries that scan all nodes, such as finding the nodes with the most children or the largest data.

<h2 id="columns">
  Columns
</h2>

* `path` ([String](/docs/reference/data-types/string)) — Absolute path of the node.
* `data` ([String](/docs/reference/data-types/string)) — Data stored in the node.
* `czxid` ([Int64](/docs/reference/data-types/int-uint)) — ID of the transaction that created the node.
* `mzxid` ([Int64](/docs/reference/data-types/int-uint)) — ID of the transaction that last modified the node.
* `ctime` ([DateTime64(3)](/docs/reference/data-types/datetime64)) — Time when the node was created.
* `mtime` ([DateTime64(3)](/docs/reference/data-types/datetime64)) — Time when the node was last modified.
* `version` ([Int32](/docs/reference/data-types/int-uint)) — Number of modifications of the node data.
* `cversion` ([Int32](/docs/reference/data-types/int-uint)) — Number of modifications of the node children.
* `aversion` ([Int32](/docs/reference/data-types/int-uint)) — Number of modifications of the node ACL.
* `ephemeral_owner` ([Int64](/docs/reference/data-types/int-uint)) — ID of the session that owns the node if it is ephemeral, `0` otherwise.
* `data_length` ([UInt32](/docs/reference/data-types/int-uint)) — Size of the node data in bytes.
* `num_children` ([Int32](/docs/reference/data-types/int-uint)) — Number of children of the node.
* `pzxid` ([Int64](/docs/reference/data-types/int-uint)) — ID of the transaction that last added or removed children of the node.
* `seq_num` ([Int64](/docs/reference/data-types/int-uint)) — Counter used to generate names of sequential children of the node.
* `ttl` ([Int64](/docs/reference/data-types/int-uint)) — TTL of the node in milliseconds if it is a TTL node, `0` otherwise.
* `acl_id` ([UInt32](/docs/reference/data-types/int-uint)) — Internal ID of the node ACL, `0` if the node has no ACL.

<h2 id="example">
  Example
</h2>

```sql theme={null}
SELECT path, num_children, data_length
FROM system.keeper_storage
ORDER BY num_children DESC
LIMIT 3;
```

```text theme={null}
┌─path──────────────┬─num_children─┬─data_length─┐
│ /                 │            3 │           0 │
│ /clickhouse/tasks │            2 │           0 │
│ /keeper           │            1 │           0 │
└───────────────────┴──────────────┴─────────────┘
```