> ## Documentation Index
> Fetch the complete documentation index at: https://risingwavelabs-wyx-add-timestamp-dedicated-page.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Sink data from RisingWave to Redis

> This guide describes how to sink data from RisingWave to Redis.

[Redis](https://redis.io) is an open-source, in-memory data structure store, often referred to as a data structure server. RisingWave sinks data to Redis in the form of strings storing key-value pairs in the specified format (`JSON` or `TEMPLATE`), so a primary key must always be provided.

You can test out this process on your own device by using the `redis-sink` demo in the [integration\_test directory](https://github.com/risingwavelabs/risingwave/tree/main/integration%5Ftests) of the RisingWave repository.

## Prerequisites

Before sinking data from RisingWave to Redis, please ensure the following:

* The Redis database you want to sink to is accessible from RisingWave.
* Ensure you have an upstream materialized view or source in RisingWave that you can sink data from.

## syntax

```sql theme={null}
CREATE SINK [ IF NOT EXISTS ] sink_name
[FROM sink_from | AS select_query]
WITH (
   connector='redis',
   connector_parameter = 'value', ...
)
FORMAT data_format ENCODE data_encode [ (
    key = 'value' ) ]
[KEY ENCODE key_encode [(...)]]
;
```

## Parameters

| Name         | Description                                                                                                                                                                                                                                                                                                                                                                   |
| :----------- | :---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| redis.url    | Required. Choose either the Redis cluster address or a non-cluster Redis address. <ul><li>If the address is a cluster address, it should be in the form of a JSON array, like `redis.url= '["redis://redis-server:6379/"]'`.</li><li>If the address is a non-cluster address, it should be in the form of a string, like `redis.url= 'redis://redis-server:6379/'`.</li></ul> |
| primary\_key | Required. The primary keys of the sink. If necessary, use `,` to delimit the primary key columns.                                                                                                                                                                                                                                                                             |

## FORMAT and ENCODE options

<Note>
  These options should be set in `FORMAT data_format ENCODE data_encode (key = 'value')`, instead of the `WITH` clause
</Note>

| Field               | Notes                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| :------------------ | :----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| data\_format        | Data format. Allowed formats:<ul><li> `PLAIN`: Output data with insert operations.</li><li> `UPSERT`: Output data as a changelog stream. </li></ul>                                                                                                                                                                                                                                                                                                                                              |
| data\_encode        | Data encoding. Supported encodings:  <ul><li>`JSON`:<ul><li>`date`: number of days since the Common Era (CE).</li></ul><ul><li>`interval`: `P<years>Y<months>M<days>DT<hours>H<minutes>M<seconds>S` format string.</li></ul><ul><li>`time without time zone`: number of milliseconds past the last midnight.</li></ul><ul><li>`timestamp`: number of milliseconds since the Epoch.</li></ul></li><li>`TEMPLATE`: converts data to the string specified by `key_format`/`value_format`.</li></ul> |
| force\_append\_only | If true, forces the sink to be `PLAIN` (also known as append-only), even if it cannot be.                                                                                                                                                                                                                                                                                                                                                                                                        |
| key\_format         | Required if `data_encode` is `TEMPLATE`. Specify the format for the key as a string.                                                                                                                                                                                                                                                                                                                                                                                                             |
| value\_format       | Required if `data_encode` is `TEMPLATE`. Specify the format for the value as a string.                                                                                                                                                                                                                                                                                                                                                                                                           |
| key\_encode         | Optional. <ul><li>When specified, the key encode can only be `TEXT`, and the primary key should be one and only one of the following types: `varchar`, `bool`, `smallint`, `int`, and `bigint`;</li><li>When absent, both key and value will use the same setting of `ENCODE data_encode ( ... )`.</li></ul>                                                                                                                                                                                     |

## Example

Assume we create a materialized view, `bhv_mv`, from a source.

```sql theme={null}
CREATE MATERIALIZED VIEW bhv_mv AS
SELECT
    user_id,
    target_id,
    event_timestamp
FROM
    source_1;
```

We can sink data from `bhv_mv` to Redis by creating a sink. Here, `data_encode` is `JSON`.

```sql theme={null}
CREATE SINK redis_sink
FROM bhv_mv WITH (
    connector = 'redis',
    primary_key = 'user_id',
    redis.url= 'redis://127.0.0.1:6379/'
) FORMAT PLAIN ENCODE JSON (
    force_append_only='true'
);
```

We can sink data from `bhv_mv` to Redis by creating a sink. Here, `data_encode` is `TEMPLATE`, so `key_format` and `value_format` must be defined.

```sql theme={null}
CREATE SINK redis_sink_2
FROM bhv_mv WITH (
    primary_key = 'user_id',
    connector = 'redis',
    redis.url= 'redis://127.0.0.1:6379/',
) FORMAT PLAIN ENCODE TEMPLATE (
    force_append_only='true',
    key_format = 'UserID:{user_id}',
    value_format = 'TargetID:{target_id},EventTimestamp{event_timestamp}'
);
```