forked from databendlabs/databend
-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
docs(weekly): add this week in databend 112 (databendlabs#13013)
* docs(weekly): add this week in databend 112 Signed-off-by: Chojan Shang <[email protected]> * docs(weekly): fix title Signed-off-by: Chojan Shang <[email protected]> * docs: apply suggestions from code review Co-authored-by: soyeric128 <[email protected]> --------- Signed-off-by: Chojan Shang <[email protected]> Co-authored-by: soyeric128 <[email protected]>
- Loading branch information
1 parent
5ca833e
commit 719f87e
Showing
2 changed files
with
136 additions
and
0 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,136 @@ | ||
| --- | ||
| title: "This Week in Databend #112" | ||
| date: 2023-09-24 | ||
| slug: 2023-09-24-databend-weekly | ||
| cover_url: 'weekly/weekly-112.jpg' | ||
| image: 'weekly/weekly-112.jpg' | ||
| tags: [weekly] | ||
| description: "Stay up to date with the latest weekly developments on Databend!" | ||
| contributors: | ||
| - name: akoshchiy | ||
| - name: andylokandy | ||
| - name: ariesdevil | ||
| - name: b41sh | ||
| - name: BohuTang | ||
| - name: dantengsky | ||
| - name: Dousir9 | ||
| - name: drmingdrmer | ||
| - name: flaneur2020 | ||
| - name: gitccl | ||
| - name: JackTan25 | ||
| - name: leiysky | ||
| - name: PsiACE | ||
| - name: RinChanNOWWW | ||
| - name: soyeric128 | ||
| - name: sundy-li | ||
| - name: TCeason | ||
| - name: xudong963 | ||
| - name: youngsofun | ||
| - name: zhang2014 | ||
| - name: zhyass | ||
| authors: | ||
| - name: PsiACE | ||
| url: https://github.com/psiace | ||
| image_url: https://github.com/psiace.png | ||
| --- | ||
|
|
||
| [Databend](https://github.com/datafuselabs/databend) is a modern cloud data warehouse, serving your massive-scale analytics needs at low cost and complexity. Open source alternative to Snowflake. Also available in the cloud: <https://app.databend.com> . | ||
|
|
||
| ## What's On In Databend | ||
|
|
||
| Stay connected with the latest news about Databend. | ||
|
|
||
| ### Understanding User-Defined Function | ||
|
|
||
| User-Defined Functions (UDFs) enable you to define their own custom operations to process data within Databend, enabling better data handling, task execution, and the creation of more efficient data workflows. | ||
|
|
||
| User-Defined Functions (UDFs) are typically written using lambda expressions or implemented via a UDF server with programming languages such as Python and are executed as part of Databend's query processing pipeline. Advantages of using UDFs include: | ||
|
|
||
| - Customized Data Transformations. | ||
| - Performance Optimization. | ||
| - Code Reusability. | ||
|
|
||
| If you are interested in learning more, please check out the resources listed below. | ||
|
|
||
| - [Docs | User-Defined Function](https://databend.rs/doc/sql-commands/ddl/udf) | ||
|
|
||
| ## Code Corner | ||
|
|
||
| Discover some fascinating code snippets or projects that showcase our work or learning journey. | ||
|
|
||
| ### Refactoring Databend Metrics Component with Prometheus | ||
|
|
||
| [metrics-rs](https://github.com/metrics-rs/metrics) is a general abstraction layer across different metrics solutions like statsd, prometheus, new-relic, etc. However, metrics-rs is not well-suited for measuring metrics about histogram. | ||
|
|
||
| Nowadays prometheus is the de facto standard in the metrics area. Using a raw Prometheus client without pushing metrics to other systems like StatsD offers several benefits: | ||
|
|
||
| - **Improved Performance**: By adhering to best practices for metric handling, memory allocation for metrics can be optimized to achieve O(1) complexity, eliminating the need for local buffered queues. | ||
| - **Minimizing Abstraction Layers**: Streamlining metric handling helps reduce unnecessary abstraction layers, simplifying the code path for improved clarity and comprehension. | ||
| - **Improved Coding Standards**: Addressing the existing variance in metric practices across different modules by adopting Prometheus community standards can help establish a more consistent and cohesive approach to metrics within our codebase. | ||
|
|
||
| Now, Databend's observability metrics have been fully migrated to Prometheus implementation. This brings you a more comprehensive and reliable observability experience while keeping the original metrics almost unchanged. | ||
|
|
||
| If you are interested in learning more, please check out the resources listed below: | ||
|
|
||
| - [PR #12787 | feat(observability): replace metrics-rs with prometheus-client](https://github.com/datafuselabs/databend/pull/12787) | ||
| - [Issue #12635 | Tracking: replace metrics-rs with prometheus-client-rs](https://github.com/datafuselabs/databend/issues/12635) | ||
| - [Issue #9422 | Feature: Refactoring Databend Metrics Component with Prometheus](https://github.com/datafuselabs/databend/issues/9422) | ||
|
|
||
| ## Highlights | ||
|
|
||
| We have also made these improvements to Databend that we hope you will find helpful: | ||
|
|
||
| - Added support for `COMPACT` distributed execution. | ||
| - Added the `json_path_exists` function. | ||
| - Added the `recluster_block_size` setting to control the block size during re-clustering. | ||
| - Added support for conversion from `DECIMAL` type to `INT` type. | ||
| - Added support for an inverted filter to optimize filter execution, leading to a performance boost of up to 4 times in certain scenarios. | ||
| - SQLSmith testing now supports generating table functions, window functions, subqueries, and the `WITH` clause. | ||
|
|
||
| ## 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. | ||
|
|
||
| ### Implementing the `GREATEST` Function | ||
|
|
||
| The `GREATEST` function returns the maximum value in a list of expressions. | ||
|
|
||
| **Syntax:** | ||
|
|
||
| ```SQL | ||
| GREATEST( <expr1> [ , <expr2> ... ] ) | ||
| ``` | ||
|
|
||
| **Example:** | ||
|
|
||
| ```SQL | ||
| SELECT id, name, category, price, rating, | ||
| CASE | ||
| WHEN rating = 1 THEN 0.02 | ||
| WHEN rating = 2 THEN 0.04 | ||
| WHEN rating = 3 THEN 0.06 | ||
| WHEN rating = 4 THEN 0.08 | ||
| ELSE 0.1 | ||
| END AS increase_percentage_based_on_rating, | ||
| rank() OVER (PARTITION BY category ORDER BY rating) AS rating_rank, | ||
| CASE | ||
| WHEN rating_rank = 1 THEN 0.2 | ||
| WHEN rating_rank = 2 THEN 0.1 | ||
| ELSE 0 | ||
| END AS increase_percentage_based_on_rank, | ||
| GREATEST(increase_percentage_based_on_rating, | ||
| increase_percentage_based_on_rank) AS final_increase_percentage, | ||
| CAST(price * (1 + final_increase_percentage) AS DECIMAL(10, 2)) | ||
| AS adjusted_price | ||
| FROM products | ||
| ``` | ||
|
|
||
| [Issue #12944 | feat: GREATEST function](https://github.com/datafuselabs/databend/issues/12944) | ||
|
|
||
| Please let us know if you're interested in contributing to this feature, or pick up a good first issue at <https://link.databend.rs/i-m-feeling-lucky> to get started. | ||
|
|
||
| ## Changelog | ||
|
|
||
| You can check the changelog of Databend Nightly for details about our latest developments. | ||
|
|
||
| **Full Changelog**: <https://github.com/datafuselabs/databend/compare/v1.2.116-nightly...v1.2.128-nightly> |
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.