---
title: 0.15.8
---

## Performance Improvements 🚀

- We have significantly improved write throughput by optimizing our segment merge policy. We introduced a new setting,
  [paradedb.segment_merge_scale_factor](/documentation/configuration/write#segment-merge-scale-factor), which allows
  expensive merge operations to be deferred until a certain number of small segments have accumulated.
- Implemented pushdown of `IS NOT NULL` into the custom scan

## Stability Improvements 💪

- We have significantly optimized the size of the BM25 index on disk. Prior to this release, the BM25 index would
  unconditionally extend the size of the index on disk on every `INSERT`/`UPDATE`/`COPY` if `VACUUM` had not been run.
  Now, the BM25 index is able to return "dead" space to the Postgres free space map as part of an `INSERT`/`UPDATE`/`COPY`,
  which means that these statements are able to reclaim existing space.

## New Contributors 👋

- [@YohDeadfall](https://github.com/YohDeadfall) made their first contribution in [#2286](https://github.com/paradedb/paradedb/pull/2286)
- [@raghunandanbhat](https://github.com/raghunandanbhat) made their first contribution in [#2264](https://github.com/paradedb/paradedb/pull/2264)

## Full Changelog

The full changelog is available [here](https://github.com/paradedb/paradedb/releases/tag/v0.15.8).