I have the following hive query:  

```
select count(distinct id) as total from mytable;

```

which automatically spawns:  

1408 Mappers  

1 Reducer

I need to manually set the number of reducers and I have tried the following:  

```
set mapred.reduce.tasks=50 
set hive.exec.reducers.max=50

```

but none of these settings seem to be honored. The query takes forever to run. Is there a way to manually set the reducers or maybe rewrite the query so it can result in more reducers? Thanks!