The TairZset (exZset) data structure allows you to sort data of the DOUBLE type based on 256 dimensions. It is ideal for implementing leaderboards for use in industries such as gaming, live streaming, music, and ecommerce. TairZset improves data processing efficiency and is also easy to implement on the client side because you do not need to encode, decode, or encapsulate the data.
Overview
The Sorted Set (also known as ZSET) data structure of open source Redis allows you to sort DOUBLEtyped scores only by one dimension instead of multiple dimensions. For example, you can use the IEEE Standard for FloatingPoint Arithmetic (IEEE 754) standard to implement multidimensional sorting by concatenating score data. However, this method has drawbacks such as complex logic, reduced precision, and unavailability of the EXZINCRBY command.
 Allows DOUBLEtyped scores to be sorted based on a maximum of 256 dimensions. The scores are displayed from left to right based on their priorities.
In a multidimensional sorting, a left score has higher priority than a right score. Take the comparison of threedimensional scores in the score1#score2#score3 format as an example. TairZset compares the score1s of multiple threedimensional scores and moves on to score2s only when score1s are equal. If score1s are not equal, the ranking of score1s represents the ranking of the threedimensional scores involved. By the same logic, score3s are compared only if score2s are equal. If all score1s are equal and the same holds true for score2s and score3s, the involved multidimensional scores are ranked in ASCII sort order.
For easier understanding, you can imagine number signs (#) as decimal points (.). This way, 0#99 < 99#90 < 99#99 can be seen as 0.99 < 99.90 < 99.99.
 Supports the EXZINCRBY command. You no longer need to perform the following operations: retrieve current data, apply the increments to the data, and then write the data back to Tair databases.
 Supports APIs similar to those available for open source Redis ZSET.
 Allows you to implement regular leaderboards and distributed leaderboards to detect malware. If malware is detected, the feature generates alert events.
 Supports the open source TairJedis client. For more information about the TairJedis client, visit GitHub. You can use the TairJedis client without the need to encode, decode, or encapsulate data. You can also encapsulate clients for other programming languages by referring to the open source code.
 Leaderboards for the livestreaming industry: In live matches, commentators are sorted by their current popularity value. If the popularity value is the same, they are sorted by the number of their likes. If the number of likes is also the same, they are sorted by the value of their gifts.
 Leaderboards for medals: Participants are sorted by the number of their gold, silver, and bronze medals. If the number of gold medals is the same, they are sorted by the number of silver medals. If the number of silver medals is also the same, they are sorted by the number of bronze medals.
 Leaderboards for the gaming industry: Players are sorted based on multiple factors, including their scores, task completion speeds, and achievement levels.
The module is opensourced. For more information, visit GitHub.
Best practices
Prerequisites
Precautions
The TairZset data that you want to manage is stored on Tair instances.
TairZset commands
Command  Syntax  Description 
EXZADD  EXZADD key [NXXX] [CH] [INCR] score member [score member ...]  Stores the specified element and its score in a TairZset key. You can specify multiple scores and elements. Note To implement multidimensional sorting, you can separate the scores of each dimension with number signs (#). Example: 111#222#121 . All elements of a key must have the same score format. 
EXZINCRBY  EXZINCRBY key increment member  Increases the score of an element in a TairZset key. increment indicates the value that you want to add to the score. 
EXZSCORE  EXZSCORE key member  Returns the score of an element in a TairZset key. If the key or the element does not exist, a value of nil is returned. 
EXZRANGE  EXZRANGE key min max [WITHSCORES]  Returns the elements of a TairZset key within the specified score range. 
EXZREVRANGE  EXZREVRANGE key min max [WITHSCORES]  Returns the elements of a TairZset key within the specified score range. Elements are stored by score in descending order, and elements with the same score are sorted in reverse lexicographical order. Note This command is similar to EXZRANGE except that this command sorts the results in reverse. 
EXZRANGEBYSCORE  EXZRANGEBYSCORE key min max [WITHSCORES] [LIMIT offset count]  Returns the elements of a TairZset key whose scores are greater than or equal to the min value and are less than or equal to the max value. The returned elements are sorted by score in ascending order, and elements with the same score are returned in lexicographical order. 
EXZREVRANGEBYSCORE  EXZREVRANGEBYSCORE key max min [WITHSCORES] [LIMIT offset count]  Returns the elements of a TairZset key whose scores are greater than or equal to the min value and are less than or equal to the max value. Contrary to the default sorting of TairZset elements, the elements returned by this command are sorted by score in descending order, and elements with the same score are sorted in reverse lexicographical order. Note This command is similar to EXZRANGEBYSCORE except that this command sorts the results in reverse and places max in front of min. 
EXZRANGEBYLEX  EXZRANGEBYLEX key min max [LIMIT offset count]  Returns the elements whose scores are between the min value and the max value when all elements of a key have the same score to ensure that elements are sorted in lexicographical order. 
EXZREVRANGEBYLEX  EXZREVRANGEBYLEX key max min [LIMIT offset count]  Returns the elements whose scores are between the min value and the max value when all elements of a key have the same score to ensure that elements are sorted in lexicographical order. Note This command is similar to EXZRANGEBYLEX except that this command sorts the results in reverse and places max in front of min. 
EXZREM  EXZREM key member [member ...]  Removes specified elements from a TairZset key. If the specified element does not exist, the element is ignored. 
EXZREMRANGEBYSCORE  EXZREMRANGEBYSCORE key min max  Removes the elements from a TairZset key whose scores are greater than or equal to the min value and are less than or equal to the max value. 
EXZREMRANGEBYRANK  EXZREMRANGEBYRANK key start stop  Removes the elements from a TairZset key whose ranks are within the range of the start value and the stop value. 
EXZREMRANGEBYLEX  EXZREMRANGEBYLEX key min max  Removes the elements whose scores are between the min value and the max value when all elements of a key have the same score to ensure that elements are sorted in lexicographical order. Note If you use the min and max parameters to specify the same range for the EXZREMRANGEBYLEX and EXZRANGEBYLEX commands, the elements removed by the EXZREMRANGEBYLEX command are the same as those returned by the EXZRANGEBYLEX command. 
EXZCARD  EXZCARD key  Returns the cardinality of a TairZset key. Cardinality indicates the number of elements in a key. 
EXZRANK  EXZRANK key member  Returns the rank of an element in a TairZset key. Ranks are sorted by score in ascending order. Ranks use a zerobased numbering scheme, and the rank of the element that has the lowest score is 0. Rank is also known as index. 
EXZREVRANK  EXZREVRANK key member  Returns the rank of an element in a TairZset key. Ranks are sorted by score in descending order. Ranks use a zerobased numbering scheme, and the rank of the element that has the highest score is 0. Rank is also known as index. Note This command is similar to EXZRANK except that this command sorts the results in reverse. 
EXZCOUNT  EXZCOUNT key min max  Returns the number of elements in a TairZset key whose scores are between the min value and the max value. 
EXZLEXCOUNT  EXZLEXCOUNT key min max  Returns the number of elements whose scores are between the min value and the max value when all elements of a key have the same score to ensure that elements are sorted in lexicographical order. 
EXZRANKBYSCORE  EXZRANKBYSCORE key score  Calculates the rank of the specified element score in a TairZset key. Ranks are sorted by score in ascending order. Ranks use a zerobased numbering scheme, and the rank of the element that has the lowest score is 0. Rank is also known as index. Note If the score does not exist, the estimated rank of the score in the key is returned. By default, if the score already exists, Tair ranks the score in front of the existing score in the key. 
EXZREVRANKBYSCORE  EXZREVRANKBYSCORE key score  Calculates the rank of the specified element score in a TairZset key. Ranks are sorted by score in descending order. Ranks use a zerobased numbering scheme, and the rank of the element that has the highest score is 0. Rank is also known as index. Note If the score does not exist, the estimated rank of the score in the key is returned. By default, if the score already exists, Tair ranks the score behind the existing score in the key. 
DEL  DEL key [key ...]  Deletes one or more TairZset keys. 
Uppercase keyword
: indicates the command keyword.Italic text
: indicates variables.[options]
: indicates that the enclosed parameters are optional. Parameters that are not enclosed by brackets must be specified.AB
: indicates that the parameters separated by the vertical bars () are mutually exclusive. Only one of the parameters can be specified....
: indicates that the parameter preceding this symbol can be repeatedly specified.
EXZADD
Item  Description 
Syntax  EXZADD key [NXXX] [CH] [INCR] score member [score member ...] 
Time complexity  O(N) 
Command description  Adds the specified element with the specified score to a TairZset key. You can specify multiple scores and elements. The system uses different strategies based on whether the key and element exist: Note To implement multidimensional sorting, you can separate the scores of each dimension with number signs (#). Example: 111#222#121 . All elements of a key must have the same score format.

Parameter 

Output  The output is an integer. The following rules describe the output:

Example  Sample command:
Sample output:

EXZINCRBY
Item  Description 
Syntax  EXZINCRBY key increment member 
Time complexity  O(log(N)) 
Command description  Increases the score of an element in a TairZset key. increment indicates the value that you want to add to the score. The system uses different strategies based on whether the key and element exist:
Note

Parameter  None 
Output  The new score of an element as a string. If multidimensional scores are used, the scores are returned in the "score1# score2# score3#..." format. Example: 2#0#6 . 
Example  Sample command:
Sample output:

EXZSCORE
Item  Description 
Syntax  EXZSCORE key member 
Time complexity  O(1) 
Command description  Returns the score of an element in a TairZset key. If the key or the element does not exist, a value of nil is returned. 
Parameter  None 
Output  The score of an element as a string. If multidimensional scores are used, the scores are returned in the "score1# score2# score3#..." format. Example: 2#0#6 . 
Example  Sample command:
Sample output:

EXZRANGE
Item  Description 
Syntax  EXZRANGE key min max [WITHSCORES] 
Time complexity  O(log(N)+M), where N indicates the number of elements in the TairZset key and M indicates the number of elements to be returned. 
Command description  Returns the elements of a TairZset key within the specified score range. 
Parameter 

Output  A list of elements within the specified score range. If the WITHSCORES parameter is specified, the scores of elements are returned. 
Example  Sample command:
Sample output:

EXZREVRANGE
Item  Description 
Syntax  EXZREVRANGE key min max [WITHSCORES] 
Time complexity  O(log(N)+M), where N indicates the number of elements in the TairZset key and M indicates the number of elements to be returned. 
Command description  Returns the elements of a TairZset key within the specified score range. Elements are stored by score in descending order, and elements with the same score are sorted in reverse lexicographical order. Note This command is similar to EXZRANGE except that this command sorts the results in reverse. 
Parameter 

Output  A list of elements within the specified score range. If the WITHSCORES parameter is specified, the scores of elements are returned. 
Example  Sample command:
Sample output:

EXZRANGEBYSCORE
Item  Description 
Syntax  EXZRANGEBYSCORE key min max [WITHSCORES] [LIMIT offset count] 
Time complexity  O(log(N)+M), where N indicates the number of elements in the TairZset key and M indicates the number of elements to be returned. Note When M is set to a constant, this expression can be regarded as O(log(N)). For example, you can specify that the first 10 elements are always returned by using the LIMIT clause. 
Command description  Returns the elements of a TairZset key whose scores are greater than or equal to the min value and are less than or equal to the max value. Returned elements are sorted by score in ascending order. Elements with the same score are returned in lexicographical order. 
Parameter 

Output  A list of elements within the specified score range. If the WITHSCORES parameter is specified, the scores of elements are returned. 
Example  Sample command:
Sample output:

EXZREVRANGEBYSCORE
Item  Description 
Syntax  EXZREVRANGEBYSCORE key max min [WITHSCORES] [LIMIT offset count] 
Time complexity  O(log(N)+M), where N indicates the number of elements in the TairZset key and M indicates the number of elements to be returned. Note When M is set to a constant, this expression can be regarded as O(log(N)). For example, you can specify that the first 10 elements are always returned by using the LIMIT clause. 
Command description  Returns the elements of a TairZset key whose scores are greater than or equal to the min value and are less than or equal to the max value. Contrary to the default sorting of TairZset elements, the elements returned by this command are sorted by score in descending order, and elements with the same score are sorted in reverse lexicographical order. Note This command is similar to EXZRANGEBYSCORE except that this command sorts the results in reverse and places max in front of min. 
Parameter 

Output  A list of elements within the specified score range. If the WITHSCORES parameter is specified, the scores of elements are returned. 
Example  Sample command:
Sample output:

EXZRANGEBYLEX
Item  Description 
Syntax  EXZRANGEBYLEX key min max [LIMIT offset count] 
Time complexity  O(log(N)+M), where N indicates the number of elements in the TairZset key and M indicates the number of elements to be returned. Note When M is set to a constant, this algorithm can be regarded as O(log(N)). For example, you can specify that the first 10 elements are always returned by using the LIMIT offset count parameter. 
Command description  Returns the elements whose scores are between the min value and the max value when all elements of a key have the same score to ensure that elements are sorted in lexicographical order. Note

Parameter 

Output  A list of elements whose values are within the specified range. 
Example  Sample command:
Sample output:

EXZREVRANGEBYLEX
Item  Description 
Syntax  EXZREVRANGEBYLEX key max min [LIMIT offset count] 
Time complexity  O(log(N)+M), where N indicates the number of elements in the TairZset key and M indicates the number of elements to be returned. Note When M is set to a constant, this expression can be regarded as O(log(N)). For example, you can specify that the first 10 elements are always returned by using the LIMIT clause. 
Command description  Returns the elements whose scores are between the min value and the max value when all elements of a key have the same score to ensure that elements are sorted in lexicographical order. Note This command is similar to EXZRANGEBYLEX except that this command sorts the results in reverse and places max in front of min. 
Parameter 

Output  A list of elements whose values are within the specified range. 
Example  Sample command:
Sample output:

EXZREM
Item  Description 
Syntax  EXZREM key member [member ...] 
Time complexity  O(M*log(N)), where N indicates the number of elements in the TairZset key and M indicates the number of elements to be removed. 
Command description  Removes specified elements from a TairZset key. If the specified element does not exist, the element is ignored. Note If the key exists but its data structure is not TairZset, an error is returned. 
Parameter  None 
Output  The number of elements removed from the key. The elements that do not exist are not included. 
Example  Sample command:
Sample output:

EXZREMRANGEBYSCORE
Item  Description 
Syntax  EXZREMRANGEBYSCORE key min max 
Time complexity  O(log(N)+M), where N indicates the number of elements in the TairZset key and M indicates the number of elements to be removed. 
Command description  Removes the elements from a TairZset key whose scores are greater than or equal to the min value and are less than or equal to the max value. 
Parameter  min: indicates the lowest score. max: indicates the highest score. If multidimensional scores are used, scores of each dimension are separated by a number sign (#). Note

Output  The number of elements removed. 
Example  Sample command:
Sample output:

EXZREMRANGEBYRANK
Item  Description 
Syntax  EXZREMRANGEBYRANK key start stop 
Time complexity  O(log(N)+M), where N indicates the number of elements in the TairZset key and M indicates the number of elements to be removed. 
Command description  Removes the elements from a TairZset key whose ranks are within the range of the start value and the stop value. 
Parameter  Both start and stop indicate zerobased indexes. 0 indicates the element that has the lowest score. These indexes can be negative numbers. These numbers indicate offsets that start at the element that has the highest score. For example, 1 indicates the element that has the highest score, and 2 indicates element that has the second highest score. Other elements follow the same rule. 
Output  The number of elements removed. 
Example  Sample command:
Sample output:

EXZREMRANGEBYLEX
Item  Description 
Syntax  EXZREMRANGEBYLEX key min max 
Time complexity  O(log(N)+M), where N indicates the number of elements in the TairZset key and M indicates the number of elements to be removed. 
Command description  Removes the elements whose scores are between the min value and the max value when all elements of a key have the same score to ensure that elements are sorted in lexicographical order. Note If you use the min and max parameters to specify the same range for the EXZREMRANGEBYLEX and EXZRANGEBYLEX commands, the elements removed by the EXZREMRANGEBYLEX command are the same as those returned by the EXZRANGEBYLEX command. 
Parameter  min: indicates the minimum string representation value of the element name. max: indicates the maximum string representation value of the element name. You must specify the intervals of characters. The following section shows how to specify intervals:

Output  The number of elements removed. 
Example  Sample command:
Sample output:

EXZCARD
Item  Description 
Syntax  EXZCARD key 
Time complexity  O(1) 
Command description  Returns the cardinality of a TairZset key. Cardinality indicates the number of elements in a key. 
Parameter  None 
Output  The number of elements in a TairZset key. If the key does not exist, a value of 0 is returned. 
Example  Sample command:
Sample output:

EXZRANK
Item  Description 
Syntax  EXZRANK key member 
Time complexity  O(log(N)) 
Command description  Returns the rank of an element in a TairZset key. Ranks are sorted by score in ascending order. Ranks use a zerobased numbering scheme, and the rank of the element that has the lowest score is 0. Rank is also known as index. 
Parameter  None 
Output 

Example  Sample command:
Sample output:

EXZREVRANK
Item  Description 
Syntax  EXZREVRANK key member 
Time complexity  O(log(N)) 
Command description  Returns the rank of an element in a TairZset key. Ranks are sorted by score in descending order. Ranks use a zerobased numbering scheme, and the rank of the element that has the highest score is 0. Rank is also known as index. Note This command is similar to EXZRANK except that this command sorts the results in reverse. 
Parameter  None 
Output 

Example  Sample command:
Sample output:

EXZCOUNT
Item  Description 
Syntax  EXZCOUNT key min max 
Time complexity  O(log(N)), where N indicates the number of elements in the TairZset key. Note This command uses element ranks to obtain the query range. Therefore, the workloads associated with this command are not proportional to the size of the range. 
Command description  Returns the number of elements in a TairZset key whose scores are between the min value and the max value. 
Parameter  min: indicates the lowest score. max: indicates the highest score. If multidimensional scores are used, scores of each dimension are separated by a number sign (#). Note

Output  The integer number of elements within the specified score range. 
Example  Sample command:
Sample output:

EXZLEXCOUNT
Item  Description 
Syntax  EXZLEXCOUNT key min max 
Time complexity  O(log(N)), where N indicates the number of elements in the TairZset key. Note This command uses element ranks to obtain the query range. Therefore, the workloads associated with this command are not proportional to the size of the range. 
Command description  Returns the number of elements whose scores are between the min value and the max value when all elements of a key have the same score to ensure that elements are sorted in lexicographical order. Note

Parameter  min: indicates the minimum string representation value of the element name. max: indicates the maximum string representation value of the element name. You must specify the intervals of characters. The following section shows how to specify intervals:

Output  The integer number of elements within the specified score range. 
Example  Sample command:
Sample output:

EXZRANKBYSCORE
Item  Description 
Syntax  EXZRANKBYSCORE key score 
Time complexity  O(log(N)) 
Command description  Calculates the rank of the specified element score in a TairZset key. Ranks are sorted by score in ascending order. Ranks use a zerobased numbering scheme, and the rank of the element that has the lowest score is 0. Rank is also known as index. Note If the score does not exist, the estimated rank of the score in the key is returned. By default, if the score already exists, Tair ranks the score in front of the existing score in the key. 
Parameter  None 
Output  The rank of the score in the key. 
Example  Sample command:
Sample output:

EXZREVRANKBYSCORE
Item  Description 
Syntax  EXZREVRANKBYSCORE key score 
Time complexity  O(log(N)) 
Command description  Calculates the rank of the specified element score in a TairZset key. Ranks are sorted by score in descending order. Ranks use a zerobased numbering scheme, and the rank of the element that has the highest score is 0. Rank is also known as index. Note If the score does not exist, the estimated rank of the score in the key is returned. By default, if the score already exists, Tair ranks the score behind the existing score in the key. 
Parameter  None 
Output  The rank of the score in the key. 
Example  Sample command:
Sample output:
