# JSON Schema Clickhouse

## Properties

| Property | Type | Required | Description |
| --- | --- | --- | --- |
| `server_settings` | [Server Settings](/reference/api/_schemas/json-schema-clickhouse/#server-settings) | no | ClickHouse server settings, which can be found in the `system.server_settings` table. |
| `tiered_storage_move_factor` | number | no | The percentage of free disk space required on local storage before data is moved to object storage. A value of 0.2 means data is moved when local storage has less than 20% free space.<br/><br/>Min: `0`. Max: `1`. Default: `0.2`. |

### Server Settings {#server-settings}

ClickHouse server settings, which can be found in the `system.server_settings` table.

| Property | Type | Required | Description |
| --- | --- | --- | --- |
| `vector_similarity_index_cache_size` | number | no | Fraction of total server memory allocated to the vector similarity index cache. 0 disables the cache. Default is 0.07 (7% of server memory). Only effective on ClickHouse 25.8+.<br/><br/>Min: `0`. Max: `0.5`. Default: `0.07`. |