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Use SUNIONSTORE to compute the union of sets and store it in another key. The destination is overwritten if it exists and deleted when the union is empty, and the reply is the number of members stored. Materializing the union is the usual way to build a combined audience once and then intersect or difference it with other sets, instead of recomputing it on every query.

Syntax

Arguments

Response

The reply reports the result of the operation. Error replies have the same shape in RESP2 and RESP3 and are surfaced as exceptions by the SDKs below.
Client libraries often decode bulk strings, maps, sets, and numeric strings into language-native values. The table describes the Redis wire reply.

Examples

TCP examples use the TLS REDIS_URL from the Upstash console. REST examples use UPSTASH_REDIS_REST_URL and UPSTASH_REDIS_REST_TOKEN.