In Hive, Mapred.reduce.tasks=-2 configuration does not work properly

hi in itversity lab even after setting mapreduce to 2 , the sort by query result execution shows only 1 reducer invoked. The configuration /command to change the reduce tasks is not working as expected --mapred.reduce.tasks=-2;

Below are the results of executing the query with sort by.
Why is it so?

hive> set mapred.reduce.tasks;
mapred.reduce.tasks=-2
hive> select order_value from order_sort sort by order_value;
Query ID = itv001358_20211105160627_8d90fd26-bbef-4621-ade6-6fb0a21d2368
Total jobs = 1
Launching Job 1 out of 1
Number of reduce tasks not specified. Estimated from input data size: 1
In order to change the average load for a reducer (in bytes):
set hive.exec.reducers.bytes.per.reducer=
In order to limit the maximum number of reducers:
set hive.exec.reducers.max=
In order to set a constant number of reducers:
set mapreduce.job.reduces=
Starting Job = job_1624709891350_45761, Tracking URL = http://m02.itversity.com:19088/proxy/application_1624709891350_45761/
Kill Command = /opt/hadoop/bin/mapred job -kill job_1624709891350_45761
Hadoop job information for Stage-1: number of mappers: 1; number of reducers: 1
2021-11-05 16:06:35,068 Stage-1 map = 0%, reduce = 0%
2021-11-05 16:06:39,249 Stage-1 map = 100%, reduce = 0%, Cumulative CPU 1.84 sec
2021-11-05 16:06:42,385 Stage-1 map = 100%, reduce = 100%, Cumulative CPU 3.19 sec
MapReduce Total cumulative CPU time: 3 seconds 190 msec
Ended Job = job_1624709891350_45761
MapReduce Jobs Launched:
Stage-Stage-1: Map: 1 Reduce: 1 Cumulative CPU: 3.19 sec HDFS Read: 10055 HDFS Write: 552 SUCCESS
Total MapReduce CPU Time Spent: 3 seconds 190 msec
OK
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Time taken: 16.87 seconds, Fetched: 33 row(s)