ZUNION

Syntax text Syntax diagram API methods

ZUNION numkeys key [key ...] [WEIGHTS weight [weight ...]]
  [AGGREGATE <SUM | MIN | MAX | COUNT>] [WITHSCORES]

Client:

zunion(
    keys: Union[Sequence[KeyT], Mapping[AnyKeyT, float]],
    aggregate: Optional[str] = None,
    withscores: bool = False,
    score_cast_func: Union[type, Callable] = float
) → ResponseT

ZUNION(
    keys: ZKeys,
    options?: ZUnionOptions
) → Any

zunion(
    params: ZParams,
    keys: String...
) → List<String>  // A set with members of the resulting set

zunion(
    keys: K...  // the keys.
) → List<V>  // List&lt;V&gt; array-reply list of elements. @since 6.1

zunion(
    aggregateArgs: ZAggregateArgs,  // arguments to define aggregation and weights.
    keys: K...  // the keys.
) → List<V>  // List&lt;V&gt; array-reply list of elements. @since 6.1

zunion(
    keys: K...  // the keys.
) → RedisFuture<List<V>>  // List&lt;V&gt; array-reply list of elements. @since 6.1

zunion(
    aggregateArgs: ZAggregateArgs,  // arguments to define aggregation and weights.
    keys: K...  // the keys.
) → RedisFuture<List<V>>  // List&lt;V&gt; array-reply list of elements. @since 6.1

zunion(
    keys: K...  // the keys.
) → Flux<V>  // V array-reply list of elements. @since 6.1

zunion(
    aggregateArgs: ZAggregateArgs,  // arguments to define aggregation and weights.
    keys: K...  // the keys.
) → Flux<V>  // V array-reply list of elements. @since 6.1

ZUnion(
    ctx: context.Context,
    store: ZStore
) → *StringSliceCmd

SortedSetCombine(
    operation: SetOperation,  // The operation to perform.
    keys: RedisKey[],  // The keys of the sorted sets.
    weights: double[]?,  // The optional weights per set that correspond to keys.
    aggregate: Aggregate,  // The aggregation method (defaults to Sum).
    flags: CommandFlags  // The flags to use for this operation.
) → RedisValue[]  // The resulting sorted set.

SortedSetCombine(
    operation: SetOperation,  // The operation to perform.
    keys: RedisKey[],  // The keys of the sorted sets.
    weights: double[]?,  // The optional weights per set that correspond to keys.
    aggregate: Aggregate,  // The aggregation method (defaults to Sum).
    flags: CommandFlags  // The flags to use for this operation.
) → RedisValue[]  // The resulting sorted set.

SortedSetCombine(
    operation: SetOperation,  // The operation to perform.
    keys: RedisKey[],  // The keys of the sorted sets.
    weights: double[]?,  // The optional weights per set that correspond to keys.
    aggregate: Aggregate,  // The aggregation method (defaults to Sum).
    flags: CommandFlags  // The flags to use for this operation.
) → RedisValue[]  // The resulting sorted set.

SortedSetCombine(
    operation: SetOperation,  // The operation to perform.
    keys: RedisKey[],  // The keys of the sorted sets.
    weights: double[]?,  // The optional weights per set that correspond to keys.
    aggregate: Aggregate,  // The aggregation method (defaults to Sum).
    flags: CommandFlags  // The flags to use for this operation.
) → RedisValue[]  // The resulting sorted set.

zunion(
    $keys: array,
    int[] $weights = []: Any,
    string $aggregate = 'sum': Any,
    bool $withScores = false: Any
) → array

Available since:: Redis Open Source 6.2.0
Time complexity:: O(N)+O(M*log(M)) with N being the sum of the sizes of the input sorted sets, and M being the number of elements in the resulting sorted set.
ACL categories:: @read, @sortedset, @slow,
Compatibility:: Redis Software and Redis Cloud compatibility

Note:

This command's behavior varies in clustered Redis environments. See the multi-key operations page for more information.

This command is similar to ZUNIONSTORE, but instead of storing the resulting sorted set, it is returned to the client.

For a description of the WEIGHTS and AGGREGATE options, see ZUNIONSTORE.

Required arguments

numkeys

The number of keys that follow.

key [key ...]

One or more sorted-set keys to union.

Optional arguments

WEIGHTS weight [weight ...]

A multiplication factor for each input set; each set's scores are multiplied by its weight before aggregation. Defaults to 1 for every set.

AGGREGATE SUM | MIN | MAX | COUNT

How to combine the scores of members that exist in multiple sets: SUM (the default), MIN, MAX, or COUNT.

WITHSCORES

Also return the score of each member.

Examples

Redis Software and Redis Cloud compatibility

Redis Software	Redis Cloud	Notes
✅ Standard ✅ Active-Active	✅ Standard ✅ Active-Active

Return information

RESP2 RESP3

Array reply: the result of the union with, optionally, their scores when WITHSCORES is used.

History

Starting with Redis version 8.8.0: Added COUNT aggregate option.