ClickHouse/docs/en/sql-reference/table-functions/redis.md
2024-01-04 09:22:40 +01:00

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---
slug: /en/sql-reference/table-functions/redis
sidebar_position: 170
sidebar_label: redis
---
# redis
This table function allows integrating ClickHouse with [Redis](https://redis.io/).
**Syntax**
```sql
redis(host:port, key, structure[, db_index[, password[, pool_size]]])
```
**Arguments**
- `host:port` — Redis server address, you can ignore port and default Redis port 6379 will be used.
- `key` — any column name in the column list.
- `structure` — The schema for the ClickHouse table returned from this function.
- `db_index` — Redis db index range from 0 to 15, default is 0.
- `password` — User password, default is blank string.
- `pool_size` — Redis max connection pool size, default is 16.
- `primary` must be specified, it supports only one column in the primary key. The primary key will be serialized in binary as a Redis key.
- columns other than the primary key will be serialized in binary as Redis value in corresponding order.
- queries with key equals or in filtering will be optimized to multi keys lookup from Redis. If queries without filtering key full table scan will happen which is a heavy operation.
[Named collections](/docs/en/operations/named-collections.md) are not supported for `redis` table function at the moment.
**Returned Value**
A table object with key as Redis key, other columns packaged together as Redis value.
## Usage Example {#usage-example}
Read from Redis:
```sql
SELECT * FROM redis(
'redis1:6379',
'key',
'key String, v1 String, v2 UInt32'
)
```
Insert into Redis:
```sql
INSERT INTO TABLE FUNCTION redis(
'redis1:6379',
'key',
'key String, v1 String, v2 UInt32') values ('1', '1', 1);
```
**See Also**
- [The `Redis` table engine](/docs/en/engines/table-engines/integrations/redis.md)
- [Using redis as a dictionary source](/docs/en/sql-reference/dictionaries/index.md#redis)