# SET LEAF

Sets a sync variable to propagate to all leaves in the cluster.

## Syntax

```

SET LEAF variable_name = value

```

## Arguments

* `variable_name`: name of the sync variable.
* `value`: value to be assigned to the sync variable.

## Remarks

* `variable_name` must be a sync variable that can sync to all nodes (aggregators and leaves).
* You cannot this command on a non-sync variable.
* This command must be run on the master aggregator.

## Examples

## Example 1

The following example syncs the variable `regexp_format` to all leaves. `SET LEAF` can be run on `regexp_format` because `regexp_format` is a variable that can sync to all nodes (leaves and aggregators). 

This is indicated in the last sentence of the Description column for the [variable](https://docs.singlestore.com/db/v9.1/reference/configuration-reference/engine-variables/list-of-engine-variables/#sync-variables-lists.md).

```sql

SET LEAF regexp_format = "extended";

```

Retrieve the variable’s value:

```sql

SELECT @@regexp_format;

```

```output

+-----------------+
| @@regexp_format |
+-----------------+
| extended        |
+-----------------+

```

## Example 2

The following example attempts to sync the variable `auto_attach` to all leaves. `SET LEAF` fails because `auto_attach` is a variable that can sync to all aggregators, only. 

This is indicated in the last sentence of the Description column for the [variable](https://docs.singlestore.com/db/v9.1/reference/configuration-reference/engine-variables/list-of-engine-variables/#sync-variables-lists-2.md).

```sql

SET LEAF auto_attach = 1;

```

```output

ERROR 2324 (HY000): This cluster-wide variable exists only on 
aggregators, it's not possible to set a value for leaves

```

## Related Topics

* See the [Engine Variables Overview](https://docs.singlestore.com/db/v9.1/reference/configuration-reference/engine-variables.md) for information about other ways to set variables.

***

Modified at: June 22, 2022

Source: [/db/v9.1/reference/sql-reference/operational-commands/set-leaf/](https://docs.singlestore.com/db/v9.1/reference/sql-reference/operational-commands/set-leaf/)

(An index of the documentation is available at /llms.txt)