---
title: 'This Week in Databend #76'
date: 2023-01-11
slug: category-weekly/2023-01-11-databend-weekly
tags: [weekly]
category: Weekly
authors:
  - PsiACE
---

[Databend](https://github.com/databendlabs/databend) is a powerful cloud data warehouse. Built for elasticity and efficiency. Free and open. Also available in the cloud: [https://app.databend.com](https://app.databend.com) .

{/* truncate */}

## What's New

Check out what we've done this week to make Databend even better for you.

### Features & Improvements :sparkles:

**Meta**

- add reader-min-msg-ver and msg-min-reader-ver in proto-conv ([#9535](https://github.com/databendlabs/databend/pull/9535))

**Planner**

- support `tuple.1` and `get(1)(tuple)` ([#9493](https://github.com/databendlabs/databend/pull/9493))
- support display estimated rows in `EXPLAIN` ([#9528](https://github.com/databendlabs/databend/pull/9528))

**Query**

- efficiently memory two level group by in standalone mode ([#9504](https://github.com/databendlabs/databend/pull/9504))

**Storage**

- support nested type in `read_parquet` ([#9486](https://github.com/databendlabs/databend/pull/9486))
- add build options table ([#9502](https://github.com/databendlabs/databend/pull/9502))

### Code Refactoring :tada:

- merge new expression ([#9411](https://github.com/databendlabs/databend/pull/9411))
- remove and rename crates ([#9481](https://github.com/databendlabs/databend/pull/9481))
- bump rust version ([#9540](https://github.com/databendlabs/databend/pull/9540))

**Expression**

- move negative functions to binder ([#9484](https://github.com/databendlabs/databend/pull/9484))
- use error_to_null() to eval try_cast ([#9545](https://github.com/databendlabs/databend/pull/9545))

**Functions**

- replace h3ron to h3o ([#9553](https://github.com/databendlabs/databend/pull/9553))

**Format**

- extract `AligningStateTextBased` ([#9472](https://github.com/databendlabs/databend/pull/9472))
- richer error context ([#9534](https://github.com/databendlabs/databend/pull/9534))

**Query**

- use ctx to store the function evaluation error ([#9501](https://github.com/databendlabs/databend/pull/9501))
- refactor map access to support view read tuple inner ([#9516](https://github.com/databendlabs/databend/pull/9516))

**Storage**

- bump opendal for streaming read support ([#9503](https://github.com/databendlabs/databend/pull/9503))
- refactor bloom index to use vectorized siphash function ([#9542](https://github.com/databendlabs/databend/pull/9542))

### Bug Fixes :wrench:

**HashTable**

- fix memory leak for unsized hash table ([#9551](https://github.com/databendlabs/databend/pull/9551))

**Storage**

- fix row group stats collection ([#9537](https://github.com/databendlabs/databend/pull/9537))

## What's On In Databend

Stay connected with the latest news about Databend.

### New Year, New Expression!

We're so thrilled to tell you that Databend now fully works with New Expression after more than a half year of dedicated work. New Expression introduces a _formal type system_ to Databend and supports _type-safe downward casting_ , making the definition of functions easier.

New Expression is still being tuned, and a new version (v0.9) of Databend will be released once the tuning work is complete.

**Learn More**

- [PR | refactor: Merge new expression](https://github.com/databendlabs/databend/pull/9411)
- [Issue | Tracking: issues about new expression](https://github.com/databendlabs/databend/issues/9480)

## What's Up Next

We're always open to cutting-edge technologies and innovative ideas. You're more than welcome to join the community and bring them to Databend.

### `UNNEST` Function

The UNNEST function takes an array as a parameter, and returns a table containing each element of the array in a row.

**Syntax**

```
UNNEST(ARRAY) [WITH OFFSET]
```

If you're interested in becoming a contributor, helping us develop the `UNNEST` function would be a good start.

[Issue 9549: Feature: Support `unnest`](https://github.com/databendlabs/databend/issues/9549)

Please let us know if you're interested in contributing to this issue, or pick up a good first issue at [https://link.databend.com/i-m-feeling-lucky](https://link.databend.com/i-m-feeling-lucky) to get started.

## Changelog

You can check the changelog of Databend Nightly for details about our latest developments.

- [v0.8.177-nightly](https://github.com/databendlabs/databend/releases/tag/v0.8.177-nightly)
- [v0.8.176-patch1](https://github.com/databendlabs/databend/releases/tag/v0.8.176-patch1)

We're gearing up for the v0.9 release of Databend. Stay tuned.

## Contributors

Thanks a lot to the contributors for their excellent work this week.

| [<img alt="andylokandy" src="https://avatars.githubusercontent.com/u/9637710?v=4&s=117" width="117" />](https://github.com/andylokandy) | [<img alt="ariesdevil" src="https://avatars.githubusercontent.com/u/7812909?v=4&s=117" width="117" />](https://github.com/ariesdevil) | [<img alt="b41sh" src="https://avatars.githubusercontent.com/u/1070352?v=4&s=117" width="117" />](https://github.com/b41sh) | [<img alt="BohuTANG" src="https://avatars.githubusercontent.com/u/172204?v=4&s=117" width="117" />](https://github.com/BohuTANG) | [<img alt="ClSlaid" src="https://avatars.githubusercontent.com/u/44747719?v=4&s=117" width="117" />](https://github.com/ClSlaid) | [<img alt="dantengsky" src="https://avatars.githubusercontent.com/u/22081156?v=4&s=117" width="117" />](https://github.com/dantengsky) |
| :-------------------------------------------------------------------------------------------------------------------------------------: | :-----------------------------------------------------------------------------------------------------------------------------------: | :-------------------------------------------------------------------------------------------------------------------------: | :------------------------------------------------------------------------------------------------------------------------------: | :------------------------------------------------------------------------------------------------------------------------------: | :------------------------------------------------------------------------------------------------------------------------------------: |
|                                              [andylokandy](https://github.com/andylokandy)                                              |                                              [ariesdevil](https://github.com/ariesdevil)                                              |                                              [b41sh](https://github.com/b41sh)                                              |                                             [BohuTANG](https://github.com/BohuTANG)                                              |                                              [ClSlaid](https://github.com/ClSlaid)                                               |                                              [dantengsky](https://github.com/dantengsky)                                               |

| [<img alt="dependabot[bot]" src="https://avatars.githubusercontent.com/in/29110?v=4&s=117" width="117" />](https://github.com/apps/dependabot) | [<img alt="drmingdrmer" src="https://avatars.githubusercontent.com/u/44069?v=4&s=117" width="117" />](https://github.com/drmingdrmer) | [<img alt="everpcpc" src="https://avatars.githubusercontent.com/u/1808802?v=4&s=117" width="117" />](https://github.com/everpcpc) | [<img alt="flaneur2020" src="https://avatars.githubusercontent.com/u/129800?v=4&s=117" width="117" />](https://github.com/flaneur2020) | [<img alt="leiysky" src="https://avatars.githubusercontent.com/u/22445410?v=4&s=117" width="117" />](https://github.com/leiysky) | [<img alt="mergify[bot]" src="https://avatars.githubusercontent.com/in/10562?v=4&s=117" width="117" />](https://github.com/apps/mergify) |
| :--------------------------------------------------------------------------------------------------------------------------------------------: | :-----------------------------------------------------------------------------------------------------------------------------------: | :-------------------------------------------------------------------------------------------------------------------------------: | :------------------------------------------------------------------------------------------------------------------------------------: | :------------------------------------------------------------------------------------------------------------------------------: | :--------------------------------------------------------------------------------------------------------------------------------------: |
|                                             [dependabot[bot]](https://github.com/apps/dependabot)                                              |                                             [drmingdrmer](https://github.com/drmingdrmer)                                             |                                              [everpcpc](https://github.com/everpcpc)                                              |                                             [flaneur2020](https://github.com/flaneur2020)                                              |                                              [leiysky](https://github.com/leiysky)                                               |                                             [mergify[bot]](https://github.com/apps/mergify)                                              |

| [<img alt="PsiACE" src="https://avatars.githubusercontent.com/u/36896360?v=4&s=117" width="117" />](https://github.com/PsiACE) | [<img alt="RinChanNOWWW" src="https://avatars.githubusercontent.com/u/33975039?v=4&s=117" width="117" />](https://github.com/RinChanNOWWW) | [<img alt="soyeric128" src="https://avatars.githubusercontent.com/u/106025534?v=4&s=117" width="117" />](https://github.com/soyeric128) | [<img alt="sundy-li" src="https://avatars.githubusercontent.com/u/3325189?v=4&s=117" width="117" />](https://github.com/sundy-li) | [<img alt="TCeason" src="https://avatars.githubusercontent.com/u/33082201?v=4&s=117" width="117" />](https://github.com/TCeason) | [<img alt="wubx" src="https://avatars.githubusercontent.com/u/320680?v=4&s=117" width="117" />](https://github.com/wubx) |
| :----------------------------------------------------------------------------------------------------------------------------: | :----------------------------------------------------------------------------------------------------------------------------------------: | :-------------------------------------------------------------------------------------------------------------------------------------: | :-------------------------------------------------------------------------------------------------------------------------------: | :------------------------------------------------------------------------------------------------------------------------------: | :----------------------------------------------------------------------------------------------------------------------: |
|                                              [PsiACE](https://github.com/PsiACE)                                               |                                              [RinChanNOWWW](https://github.com/RinChanNOWWW)                                               |                                               [soyeric128](https://github.com/soyeric128)                                               |                                              [sundy-li](https://github.com/sundy-li)                                              |                                              [TCeason](https://github.com/TCeason)                                               |                                             [wubx](https://github.com/wubx)                                              |

| [<img alt="Xuanwo" src="https://avatars.githubusercontent.com/u/5351546?v=4&s=117" width="117" />](https://github.com/Xuanwo) | [<img alt="xudong963" src="https://avatars.githubusercontent.com/u/41979257?v=4&s=117" width="117" />](https://github.com/xudong963) | [<img alt="youngsofun" src="https://avatars.githubusercontent.com/u/5782159?v=4&s=117" width="117" />](https://github.com/youngsofun) | [<img alt="zhang2014" src="https://avatars.githubusercontent.com/u/8087042?v=4&s=117" width="117" />](https://github.com/zhang2014) |
| :---------------------------------------------------------------------------------------------------------------------------: | :----------------------------------------------------------------------------------------------------------------------------------: | :-----------------------------------------------------------------------------------------------------------------------------------: | :---------------------------------------------------------------------------------------------------------------------------------: |
|                                              [Xuanwo](https://github.com/Xuanwo)                                              |                                              [xudong963](https://github.com/xudong963)                                               |                                              [youngsofun](https://github.com/youngsofun)                                              |                                              [zhang2014](https://github.com/zhang2014)                                              |