Databend Weekly

Databend is an open source elastic and reliable Modern Cloud Data Warehouse, it offers blazing fast query and combines elasticity, simplicity, low cost of the cloud, built to make the Data Cloud easy.

Big changes

Below is a list of some major changes that we don't want you to miss.

Features

undrop database (#5770)
support async insert mode to improve throughput (#5567)
support alter table cluster key (#5718)

meta

add gc out of drop retention time data schema API and unit tests (#5746)
protobuf message has to persist MIN_COMPATIBLE_VER (#5785)

functions

support function timezone() (#5840)
add function NULLIF (#5772)

new planner

introduce InterpreterFactoryV2 for new planner (#5729)
support udf (#5751)
CREATE VIEW (#5816)
CREATE DATABASE (#5804) / DROP DATABASE (#5846)
CREATE USER (#5802) / ALTER USER (#5823) / DROP USER (#5813)

Improvement

refactor location parse logic (#5790)
show tenant quota for current tenant (#5750)
support errorcode hint in new planner (#5756)
don't load credential while reading stage (#5783)
move Clickhouse HTTP handler to its own port (#5797)

new parser

support cross join (#5730)
flatten join lists (#5742)

Build / Testing / CI

enable logic test (#5836)

Bug fixes

fix compressed buf not consumed correctly (#5727)
support abort for pipeline executor stream (#5803)
lz4raw compression of zero len buffer (#5806)
fix server hang when sync work panic (#5814)

Tips

Let's learn a weekly tip from Databend.

Databend Supports Async Insert Mode

When thousands of clients concurrently insert a small batch of data, each insert will be executed as follows:

Parser -> Planner -> Interpreter -> Pipeline

It's inefficient because of I/O depth and cache locality.

To solve the problem, we want to buffer small inserts into batches in server which sacrifices tiny latency for better insert throughput, smaller block count and larger DataBlock in storage.

After doing this, inserts into the same table will be parsed and planned individual. The insert data will be convert to DataBlock and buffered. When some conditions are triggered, the buffered DataBlock will be interpreted once which also is beneficial for pipelines.

Learn more:

Changelogs

You can check the changelogs of Databend nightly to learn about our latest developments.

Contributors

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


andylokandy	b41sh	BohuTANG	dantengsky	devillove084	drmingdrmer


everpcpc	fkuner	flaneur2020	hantmac	junnplus	leiysky


lichuang	LiuYuHui	mergify[bot]	RinChanNOWWW	soyeric128	sundy-li


TCeason	Xuanwo	xudong963	ygf11	youngsofun	ZeaLoVe


zhang2014	zhyass

Meet Us

Please join the DatafuseLabs Community if you are interested in Databend.

We are looking forward to seeing you try our code. We have a strong team behind you to ensure a smooth experience in trying our code for your projects. If you are a hacker passionate about database internals, feel free to play with our code.

You can submit issues for any problems you find. We also highly appreciate any of your pull requests.

This week in Databend #45