druid/docs/content/LimitSpec.md

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# Sort groupBy Query Results
The limitSpec field provides the functionality to sort and limit the set of results from a groupBy query. If you group by a single dimension and are ordering by a single metric, we highly recommend using [TopN Queries](TopNQuery.html) instead. The performance will be substantially better. Available options are:
### DefaultLimitSpec
The default limit spec takes a limit and the list of columns to do an orderBy operation over. The grammar is:
```json
{
"type" : "default",
"limit" : <integer_value>,
"columns" : [list of OrderByColumnSpec],
}
```
#### OrderByColumnSpec
OrderByColumnSpecs indicate how to do order by operations. Each order-by condition can be a `jsonString` or a map of the following form:
```json
{
"dimension" : "<Any dimension or metric name>",
"direction" : <"ascending"|"descending">
}
```
If only the dimension is provided (as a JSON string), the default order-by is ascending.