Index Overview

Indexes are used to help quickly filter or search for data. Currently, Doris supports two types of indexes: built-in smart indexes and user-created secondary indexes.

Built-in smart indexes

• Sorted keys and prefix index: Apache Doris stores data in an ordered manner based on sorted keys. It creates a prefix index for every 1024 rows of data. The key in the index is the value of the sorted column in the first row of the current 1024-row group. If a query involves a sorted column, the system will find the first row of the relevant 1024-row group and start scanning from there.
• ZoneMap index: The ZoneMap index is automatically maintained index information for each column in the column-based storage format, including Min/Max values, etc. This type of index is transparent to users. These are segment and page-level indexes, the maximum and minimum values for each column within a page are recorded, and the maximum and minimum values for each column within a segment are also recorded. Therefore, in equivalence and range queries, this Min/Max index can be used to narrow down the filtering range.

User-created secondary indexes

• Bloom Filter Index
• N-Gram Bloom Filter Index
• Bitmap Index
• Inverted Index