Range Index

Range indexing allows you to get better performance for queries that involve filtering over a range.

It would be useful for a query like the following:

SELECT COUNT(*) 
FROM baseballStats 
WHERE hits > 11

A range index is a variant of an inverted index, where instead of creating a mapping from values to columns, we create mapping of a range of values to columns. You can use the range index by setting the following config in the table config.

{
    "tableIndexConfig": {
        "rangeIndexColumns": [
            "column_name",
            ...
        ],
        ...
    }
}

Range index is supported for both dictionary as well as raw encoded columns.

DO NOT use range index v2 (default version) on raw encoded INT/LONG columns because there is a bug that can cause wrong result. The bug is fixed in https://github.com/apache/pinot/pull/9453

When to use Range Index?

A good thumb rule is to use a range index when you want to apply range predicates on metric columns that have a very large number of unique values.

Using an inverted index for such columns will create a very large index that is inefficient in terms of storage and performance.