Range queries for scoring in Redis - Cheat Sheet & Quick Revision

Recall & Review

beginner

What Redis data structure is commonly used for range queries based on scores?

Redis Sorted Sets are used for range queries based on scores because they store members ordered by their score values.

beginner

Which Redis command retrieves members with scores between a minimum and maximum value?

The command ZRangeByScore retrieves members with scores within a specified range.

intermediate

How do you include the scores in the results when performing a range query in Redis?

Use the WITHSCORES option with ZRangeByScore to get both members and their scores.

intermediate

What symbol do you use in Redis range queries to represent negative or positive infinity?

Use -inf for negative infinity and +inf for positive infinity to specify open-ended ranges.

intermediate

How can you limit the number of results returned by a Redis range query?

Use the LIMIT offset count option with ZRangeByScore to restrict the number of returned members.

Which Redis command fetches members with scores between 10 and 20?

A ZSCORE key 10 20

B ZRANGE key 10 20

C ZRANGEBYSCORE key 10 20

D ZGETRANGE key 10 20

ZRANGEBYSCORE is the correct command to fetch members within a score range.

How do you get the scores along with members in a range query?

A Add WITHSCORES option

B Add GETSCORES option

C Add SHOWSCORES option

D Add SCORES option

The WITHSCORES option returns scores with members.

What does -inf mean in a Redis range query?

A Zero score

B Negative infinity, lowest possible score

C Positive infinity, highest possible score

D No score

-inf represents negative infinity, meaning no lower limit.

Which option limits the number of results in ZRangeByScore?

A LIMIT offset count

B COUNT offset limit

C MAX offset count

D OFFSET limit count

LIMIT offset count restricts the number of returned members.

If you want all members with scores greater than or equal to 50, what is the correct range?

A -inf +inf

B -inf 50

C 0 50

D 50 +inf

Using 50 +inf fetches all members with scores from 50 upwards.

Explain how to perform a range query in Redis to get members with scores between two values, including how to get their scores and limit results.

Think about the command and options you add for scores and limits.

Describe the meaning and use of -inf and +inf in Redis range queries.

They help when you want to query from or up to any score.