SUNIONSTORE for storing results in Redis - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the Redis command SUNIONSTORE do?

It creates a new set by combining all unique members from given sets and stores the result in a specified destination key.

beginner

How do you use SUNIONSTORE to combine sets set1 and set2 into resultSet?

Use the command: SUNIONSTORE resultSet 2 set1 set2. This stores the union of set1 and set2 in resultSet.

intermediate

What happens if the destination key in SUNIONSTORE already exists?

The existing key is overwritten with the new union set.

beginner

Can SUNIONSTORE be used with just one set?

Yes, but it simply copies that set to the destination key.

beginner

What type of data structure does SUNIONSTORE work with in Redis?

It works only with sets, which are collections of unique strings.

What does SUNIONSTORE dest set1 set2 do?

A Stores the intersection of set1 and set2 in dest

B Stores the union of set1 and set2 in dest

C Deletes set1 and set2

D Copies set1 to set2

SUNIONSTORE combines all unique members from the given sets and stores them in the destination key.

If dest already exists, what happens when you run SUNIONSTORE dest set1 set2?

A dest is deleted

B An error occurs

C dest is overwritten with the union

D dest remains unchanged

The existing dest key is overwritten with the new union set.

Which Redis data type is required for SUNIONSTORE?

A Sets

B Hashes

C Strings

D Lists

SUNIONSTORE works only with sets.

What result does SUNIONSTORE dest set1 produce?

A Copies set1 to dest

B Deletes set1

C Creates an empty set

D Throws an error

Using one set copies it to the destination key.

Which command would you use to combine multiple sets and save the result in Redis?

A SADD

B SINTERSTORE

C SMEMBERS

D SUNIONSTORE

SUNIONSTORE combines sets and stores the union.

Explain how the Redis command SUNIONSTORE works and when you would use it.

Think about combining unique items from different groups and saving them.

Describe what happens if the destination key already exists when using SUNIONSTORE.

Consider how Redis handles keys when storing new data.