# ClickHouse projections now behave like true secondary indexes

DevFeed: [ClickHouse projections now behave like true secondary indexes](<https://devfeed.tech/articles/clickhouse-projections-now-behave-like-true-secondary-indexes-5529.md>)

Original publisher: [Read original article](<https://clickhouse.com/blog/projections-secondary-indices>)

Author: Tom Schreiber

Published: 2026-01-13T00:00:00Z

Content type: article

Language: en

Sources: [ClickHouse Blog](<https://devfeed.tech/sources/clickhouse-blog.md>)

Topics: [clickhouse](<https://devfeed.tech/topics/clickhouse.md>), [data](<https://devfeed.tech/topics/data.md>), [Sorting](<https://devfeed.tech/topics/sorting.md>)

Tags: [clickhouse](<https://devfeed.tech/tags/clickhouse.md>), [cost](<https://devfeed.tech/tags/cost.md>), [data](<https://devfeed.tech/tags/data.md>), [release](<https://devfeed.tech/tags/release.md>), [sorting](<https://devfeed.tech/tags/sorting.md>), [speed](<https://devfeed.tech/tags/speed.md>), [storage](<https://devfeed.tech/tags/storage.md>)

## AI overview

ClickHouse introduces lightweight projections that function as secondary indexes without duplicating full table rows. With granule-level pruning, multiple projections can work with the base table's primary index to accelerate queries using several filters while reducing storage overhead.

## Source excerpt

ClickHouse now supports granule-level pruning for lightweight projections, enabling them to act as true secondary indexes that work together to dramatically speed up multi-filter queries without duplicating full table data.