> ## Documentation Index
> Fetch the complete documentation index at: https://docs.risingwave.com/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. - If the address is a cluster address, it should be in the form of a JSON array, like `redis.url= '["redis://redis-server:6379/"]'`.
- If the address is a non-cluster address, it should be in the form of a string, like `redis.url= 'redis://redis-server:6379/'`.
To use TLS for secure connections, use the `rediss://` protocol instead of `redis://`. |
| primary\_key | **Required**. The primary keys of the sink. If necessary, use `,` to delimit the primary key columns. |
## FORMAT and ENCODE options
These options should be set in `FORMAT data_format ENCODE data_encode (key = 'value')`, instead of the `WITH` clause.
| Field | Notes |
| :------------------ | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| data\_format | Data format. Allowed formats:- `PLAIN`: Output data with insert operations.
- `UPSERT`: Output data as a changelog stream.
|
| data\_encode | Data encoding. Supported encodings: - `JSON`
- `date`: number of days since the Common Era (CE).
- `interval`: `PYMDTHMS` format string.
- `time without time zone`: number of milliseconds past the last midnight.
- `timestamp`: number of milliseconds since the Epoch.
- `TEMPLATE`: converts data to the string specified by `key_format`/`value_format`.
- Use `{column_name}` to insert a column's value.
- To include a literal `{` or `}` character, escape it with a backslash: `\{` or `\}`. Backslash not followed by brace preserves its original meaning, like the first character in `\\{` and this template outputs `\{`.
|
| force\_append\_only | If true, forces the sink to be `PLAIN` (also known as append-only), even if it cannot be. |
| key\_format | Specify the format for the key as a string. |
| value\_format | Specify the format for the value as a string. |
| key\_encode | **Optional**. - 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`;
- When absent, both key and value will use the same setting of `ENCODE data_encode ( ... )`.
|
| redis\_value\_type | **Optional**. Controls how data is written to Redis. For details, see [examples](#example) below.- `string` (Default): Key-value storage. `key_format` and `value_format` are required.
- `pubsub`: Publishes messages to Redis Pub/Sub channels. `value_format` is required.
- `geospatial`: Stores data using Redis' geospatial index. `key_format` is required.
- `stream`: Publishes messages to Redis Streams. `key_format` and `value_format` are required.
|
| channel | **Optional**. Required if `redis_value_type = 'pubsub'` and `channel_column` is not set. The name of the Redis Pub/Sub channel to publish messages to. |
| channel\_column | **Optional**. Required if `redis_value_type = 'pubsub'` and `channel` is not set. The values from this column will be used as the names of the Redis Pub/Sub channels to publish messages to. Must be type of `VARCHAR`. |
| stream | **Optional**. Required if `redis_value_type = 'stream'` and `stream_column` is not set. The name of the Redis Stream to publish messages to. |
| stream\_column | **Optional**. Required if `redis_value_type = 'stream'` and `stream` is not set. The values from this column will be used as the names of the Redis Streams to publish messages to. Must be type of `VARCHAR`. |
| longitude | **Optional**. Required if `redis_value_type = 'geospatial'`. Contains the longitude value. Must be of type `FLOAT`, `REAL`, or `VARCHAR`. |
| latitude | **Optional**. Required if `redis_value_type = 'geospatial'`. Contains the latitude value. Must be of type `FLOAT`, `REAL`, or `VARCHAR`. |
| member | **Optional**. Required when `redis_value_type = 'geospatial'`. Contains the member names for the geospatial set. Must be of type `VARCHAR` and part of the primary key. |
## Example
This section provides examples for sinking data from RisingWave to Redis, covering key-value storage, geospatial data storage, Pub/Sub messaging, and streams.
### Key-value storage
This approach is suitable when you want to use Redis as a fast data store or cache, storing data as key-value pairs. Specify `redis_value_type = 'string'` or omit this parameter, as `string` is the default.
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}'
);
```
### Geospatial data storage
This approach allows RisingWave to store geospatial data (longitude, latitude, member) in Redis. Make sure to specify `FORMAT UPSERT ENCODE TEMPLATE`, `redis_value_type = 'geospatial'`, `key_format`, `longitude`, `latitude`, and `member`.
Assume we have a table `t1`:
```sql theme={null}
CREATE TABLE t1(v1 float, v2 float, v3 varchar, v4 varchar);
```
We can sink geospatial data to Redis:
```sql theme={null}
CREATE SINK s1
FROM
t1 WITH (
primary_key = 'v3,v4',
connector = 'redis',
redis.url= 'redis://127.0.0.1:6379/',
)FORMAT UPSERT ENCODE TEMPLATE
(redis_value_type ='geospatial',
longitude = 'v1',
latitude = 'v2',
member = 'v3',
key_format = 'abcd3:{v4}'
);
```
Now insert the geospatial data into the table `t1`:
```sql theme={null}
INSERT INTO t1 VALUES (1.1, 1.1, 'test','test');
```
You can retrieve the geospatial information from Redis:
```
GEOPOS abcd3:test test
------
1) 1) "1.10000044298171997"
2) "1.10000000482478555"
```
For more information, see [Geospatial indexing](https://redis.io/glossary/geospatial-indexing/).
### Pub/Sub messaging
This approach allows RisingWave to publish messages to Redis channels. Make sure to specify `FORMAT UPSERT ENCODE TEMPLATE`, `redis_value_type = 'pubsub'`, and `value_format`. Specify either `channel` or `channel_column`. These two parameters are mutually exclusive.
Assume we have a table `t1`:
```sql theme={null}
CREATE TABLE t1(v1 float, v2 float, v3 varchar, v4 varchar);
```
We can sink data from `t1` as messages to a predefined Redis Pub/Sub channel:
```sql theme={null}
CREATE SINK s1
FROM
t1 WITH (
primary_key = 'v3,v4',
connector = 'redis',
redis.url= 'redis://127.0.0.1:6379/',
)FORMAT UPSERT ENCODE TEMPLATE
(redis_value_type ='pubsub',
channel= 'test123',
value_format = 'abcd3:{v4}'
);
```
Alternatively, you can publish to a dynamic channel using `channel_column`:
```sql theme={null}
CREATE SINK s1
FROM
t1 WITH (
primary_key = 'v3,v4',
connector = 'redis',
redis.url= 'redis://127.0.0.1:6379/',
)FORMAT UPSERT ENCODE TEMPLATE
(redis_value_type ='pubsub',
channel_column = 'v3',
value_format = 'abcd3:{v4}'
);
```
### Streams
Added in v2.7.0.
**PREMIUM FEATURE**
This is a premium feature. For a comprehensive overview of all premium features and their usage, please see [RisingWave premium features](/get-started/premium-features).
This approach allows RisingWave to publish messages to Redis Streams. Redis Streams is a data structure that acts as an append-only log. Make sure to specify `FORMAT PLAIN ENCODE TEMPLATE`, `redis_value_type = 'stream'`, `key_format`, and `value_format`. Specify either `stream` or `stream_column`. These two parameters are mutually exclusive.
Assume we have a table `t1`:
```sql theme={null}
CREATE TABLE t1(v1 float, v2 float, v3 varchar, v4 varchar);
```
We can sink data from `t1` as messages to a predefined Redis Stream:
```sql theme={null}
CREATE SINK s1
FROM
t1 WITH (
primary_key = 'v3,v4',
connector = 'redis',
redis.url= 'redis://127.0.0.1:6379/',
) FORMAT PLAIN ENCODE TEMPLATE
(redis_value_type ='stream',
stream = 'test123',
key_format = 'abcd3:{v3}',
value_format = 'abcd3:{v4}'
);
```
Alternatively, you can publish to a dynamic stream using `stream_column`:
```sql theme={null}
CREATE SINK s1
FROM
t1 WITH (
primary_key = 'v3,v4',
connector = 'redis',
redis.url= 'redis://127.0.0.1:6379/',
) FORMAT PLAIN ENCODE TEMPLATE
(redis_value_type ='stream',
stream_column = 'v3',
key_format = 'abcd3:{v3}',
value_format = 'abcd3:{v4}'
);
```