docs/versioned_docs/version-3.0.0/developers-guide/sql/system-views.md

---
title: System Views
sidebar_label: System Views
---

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Ignite provides a number of built-in SQL views that provide information on the cluster's state and provide real-time insight into the status of its components. These views are available in the SYSTEM schema.

## Getting Data

You access system views in Ignite by using SQL and selecting data from the system view like you would from any other table. For example, you can get a list of all available system views in the following way:

```sql
SELECT id, schema, name FROM system.system_views WHERE type = 'NODE'
```

You can also use joins to combine data from multiple views. The example below returns all columns of a view that was found in the `SYSTEM_VIEWS` view:

```sql
SELECT svc.*
  FROM system.system_view_columns svc
  JOIN system.system_views sv ON svc.view_id = sv.id
 WHERE sv.name = 'SYSTEM_VIEWS'
```

## Available Views

### SYSTEM_VIEWS

Describes available system views.

| Column | Data Type | Description |
|--------|-----------|-------------|
| ID | INT32 | System view ID. |
| SCHEMA | STRING | Name of the schema used. Default is `SYSTEM`. |
| NAME | STRING | System view name. |
| TYPE | STRING | System view type. Possible values:<br/><br/>* NODE - The view provides node-specific information. Data will be collected from all nodes, and represented in the view.<br/>* CLUSTER - The view provides cluster-wide information. Data will be collected from one node, chosen to represent the cluster. |

### SYSTEM_VIEW_COLUMNS

Describes available system view columns.

| Column | Data Type | Description |
|--------|-----------|-------------|
| VIEW_ID | INT32 | System view ID. |
| NAME | STRING | Column name. |
| TYPE | STRING | Column type. Can by any of the [supported types](../../sql-reference/data-types.md). |
| NULLABLE | BOOLEAN | Defines if the column can be empty. |
| PRECISION | INT32 | Maximum number of digits. |
| SCALE | INT32 | Maximum number of decimal places. |
| LENGTH | INT32 | Maximum length of the value. Symbols for string values or bytes for binary values. |

### SYSTEM.ZONES

| Column | Data Type | Description |
|--------|-----------|-------------|
| NAME | STRING | The name of the distribution zone. |
| PARTITIONS | INT32 | The number of partitions in the distribution zone. |
| REPLICAS | STRING | The number of copies of each partition in the distribution zone. |
| DATA_NODES_AUTO_ADJUST_SCALE_UP | INT32 | The delay in seconds between the new node joining and the start of data zone adjustment. |
| DATA_NODES_AUTO_ADJUST_SCALE_DOWN | INT32 | The delay in seconds between the node leaving the cluster and the start of data zone adjustment. |
| DATA_NODES_FILTER | STRING | The filter that specifies what nodes will be used by the distribution zone. |
| IS_DEFAULT_ZONE | BOOLEAN | Defines if the data zone is used by default. |