# LIMIT

Published articles for LIMIT.

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## 【kube-apiserver】List、Pagination 与一致性 List：continue token 与 etcd Range 成本

DevFeed: [【kube-apiserver】List、Pagination 与一致性 List：continue token 与 etcd Range 成本](<https://devfeed.tech/articles/kube-apiserver-list-pagination-list-continue-token-etcd-range-33962.md>)

Original publisher: [Read original article](<https://quant67.com/post/apiserver/06-list-pagination/06-list-pagination.html>)

Author: Liao Tonglang

Published: 2026-08-28T00:00:00Z

Content type: tutorial

Language: zh

Sources: [土法炼钢 - 系统与基础设施](<https://devfeed.tech/sources/source-4.md>)

Topics: [Kubernetes](<https://devfeed.tech/topics/kubernetes.md>), [API](<https://devfeed.tech/topics/api.md>), [Cache](<https://devfeed.tech/topics/cache.md>), [version](<https://devfeed.tech/topics/version.md>)

Tags: [410-gone](<https://devfeed.tech/tags/410-gone.md>), [apiserver](<https://devfeed.tech/tags/apiserver.md>), [cacher](<https://devfeed.tech/tags/cacher.md>), [continue-token](<https://devfeed.tech/tags/continue-token.md>), [distributed](<https://devfeed.tech/tags/distributed.md>), [etcd](<https://devfeed.tech/tags/etcd.md>), [etcd-range](<https://devfeed.tech/tags/etcd-range.md>), [http](<https://devfeed.tech/tags/http.md>), [kubernetes](<https://devfeed.tech/tags/kubernetes.md>), [limit](<https://devfeed.tech/tags/limit.md>), [list](<https://devfeed.tech/tags/list.md>), [pagination](<https://devfeed.tech/tags/pagination.md>), [range](<https://devfeed.tech/tags/range.md>), [resourceversion](<https://devfeed.tech/tags/resourceversion.md>), [v1-30-3](<https://devfeed.tech/tags/v1-30-3.md>)

### AI overview

This article examines Kubernetes v1.30.3 List pagination in kube-apiserver, explaining continue-token semantics, limit-and-continue etcd Range behavior, resourceVersion consistency, and the different costs of cacher and etcd3 paths. It also explains how label and field selectors affect scanning and filtering.

### Source excerpt

钉 Kubernetes v1.30.3 List 分页的 continue token 编码语义、limit+continue 多轮 etcd Range 行为、resourceVersion 对一致性语义的影响，以及 label/field selector 在 cacher 与 etcd3 路径上的不同成本。

## An Efficient Way to Check for Existence of Multiple Values in SQL

DevFeed: [An Efficient Way to Check for Existence of Multiple Values in SQL](<https://devfeed.tech/articles/an-efficient-way-to-check-for-existence-of-multiple-values-in-sql-28931.md>)

Original publisher: [Read original article](<https://blog.jooq.org/an-efficient-way-to-check-for-existence-of-multiple-values-in-sql/>)

Author: lukaseder

Published: 2024-02-16T14:16:45Z

Content type: tutorial

Language: en

Sources: [jOOQ](<https://devfeed.tech/sources/jooq.md>)

Topics: [SQL](<https://devfeed.tech/topics/sql.md>), [Benchmark](<https://devfeed.tech/topics/benchmark.md>), [Oracle Database](<https://devfeed.tech/topics/oracle-database.md>), [PostgreSQL](<https://devfeed.tech/topics/postgresql.md>)

Tags: [benchmark](<https://devfeed.tech/tags/benchmark.md>), [benchmarking](<https://devfeed.tech/tags/benchmarking.md>), [compare](<https://devfeed.tech/tags/compare.md>), [count](<https://devfeed.tech/tags/count.md>), [database](<https://devfeed.tech/tags/database.md>), [derived-table](<https://devfeed.tech/tags/derived-table.md>), [execution](<https://devfeed.tech/tags/execution.md>), [exists](<https://devfeed.tech/tags/exists.md>), [join](<https://devfeed.tech/tags/join.md>), [limit](<https://devfeed.tech/tags/limit.md>), [mysql](<https://devfeed.tech/tags/mysql.md>), [oracle](<https://devfeed.tech/tags/oracle.md>), [oracle-23c](<https://devfeed.tech/tags/oracle-23c.md>), [performance](<https://devfeed.tech/tags/performance.md>), [postgresql](<https://devfeed.tech/tags/postgresql.md>), [rdbms](<https://devfeed.tech/tags/rdbms.md>), [sql](<https://devfeed.tech/tags/sql.md>), [sql-performance](<https://devfeed.tech/tags/sql-performance.md>), [sql-server](<https://devfeed.tech/tags/sql-server.md>), [sql-syntax](<https://devfeed.tech/tags/sql-syntax.md>), [top](<https://devfeed.tech/tags/top.md>)

### AI overview

This article explains how to check whether multiple matching rows exist in SQL. It recommends limiting rows in a derived table before counting them, then compares execution plans and benchmark results for PostgreSQL 15 and Oracle 23c.

### Source excerpt

In a previous blog post, we've advertised the use of SQL EXISTS rather than COUNT(*) to check for existence of a value in SQL. I.e. to check if in the Sakila database, actors called WAHLBERG have played in any films, instead of: Do this: (Depending on your dialect you may require a FROM DUAL clause, ... Continue reading An Efficient Way to Check for Existence of Multiple Values in SQL ->

## Building a ChatGPT Add-On for Google Workspace: Integration Challenges and Lessons Learned

DevFeed: [Building a ChatGPT Add-On for Google Workspace: Integration Challenges and Lessons Learned](<https://devfeed.tech/articles/overcoming-the-hurdle-of-unformatted-input-what-i-learned-from-building-a-chatgpt-add-on-for-35648.md>)

Original publisher: [Read original article](<https://engineering.klarna.com/building-a-chatgpt-add-on-my-journey-to-streamlined-communication-in-google-workspace-60e73ec00084?source=rss----86090d14ab52---4>)

Author: Mikael Wulfcrona

Published: 2023-10-16T09:50:38Z

Content type: opinion

Language: en

Sources: [Klarna Engineering](<https://devfeed.tech/sources/klarna-engineering.md>)

Topics: [ChatGPT](<https://devfeed.tech/topics/chatgpt.md>), [Google Apps Script](<https://devfeed.tech/topics/google-apps-script.md>), [Google](<https://devfeed.tech/topics/google.md>), [API](<https://devfeed.tech/topics/api.md>), [JavaScript](<https://devfeed.tech/topics/javascript.md>), [Language models](<https://devfeed.tech/topics/language-models.md>)

Tags: [add-ons](<https://devfeed.tech/tags/add-ons.md>), [api](<https://devfeed.tech/tags/api.md>), [challenges](<https://devfeed.tech/tags/challenges.md>), [chatgpt](<https://devfeed.tech/tags/chatgpt.md>), [google-workspace](<https://devfeed.tech/tags/google-workspace.md>), [javascript](<https://devfeed.tech/tags/javascript.md>), [langchain](<https://devfeed.tech/tags/langchain.md>), [limit](<https://devfeed.tech/tags/limit.md>), [productivity](<https://devfeed.tech/tags/productivity.md>), [work](<https://devfeed.tech/tags/work.md>)

### AI overview

The author describes building a Google Workspace add-on that integrates ChatGPT for textual interactions with data in Google Sheets. The main challenges included extracting text across Google Workspace, ChatGPT's token limit, the 60-second execution limit for Google add-ons, and handling raw spreadsheet data.

### Source excerpt

Overcoming the Hurdle of Unformatted Input: What I Learned From Building a ChatGPT Add-On for Google Workspace While ChatGPT is an incredibly powerful language model, it still struggles with unformatted input. As a tech nerd and passionate data scientist, I recently embarked on a journey to create an add-on for Google Workspace that could seamlessly interact with data stored in Sheets. Follow along as I share some of the main challenges, learnings, and solutions that eventually allowed me to integrate ChatGPT into Google's productivity tools for textual interactions. Unleashing the Potential of ChatGPT I was one of many people who was very impressed with the early versions of ChatGPT, released at the end of last year. Its capability to generate human-like responses fascinated me. However, I struggled to integrate it into my daily work. Having to switch tabs and copy-pasting text from different documents kept me away from really adopting this new tool. Determined to overcome this hurdle, I dove into the world of Google Workspace add-ons. You know where the work with text actually happens. Armed with enthusiasm and basic JavaScript knowledge, I got into building my first add-on. Having never built an add-on before, I forked Google's own example repo and started working. Working with the Google API As I delved into the project, I realized integrating ChatGPT via API calls was relatively straightforward. OpenAI provided excellent documentation, and Google Apps Script offered built-in features to make API calls. The main challenges, actually, laid on the Google side. Extracting text from different apps within the Google Workspace ecosystem initially baffled me. I spent hours unraveling the intricacies of the Google API, determined to find a way to seamlessly access and manipulate data. Overcoming GPT's Limitations with Raw Data in Google Sheets As I progressed, I encountered more roadblocks. Firstly, the infamous token limit. Some document were quite long and simply not

## SSH Hardening to Prevent Brute-Force Attacks

DevFeed: [SSH Hardening to Prevent Brute-Force Attacks](<https://devfeed.tech/articles/ssh-hardening-to-prevent-brute-force-attacks-29870.md>)

Original publisher: [Read original article](<https://goteleport.com/blog/ssh-hardening-to-prevent-brute-force-attacks/>)

Author: info@goteleport.com (Robert Watson)

Published: 2022-01-14T00:00:00Z

Content type: tutorial

Language: en

Sources: [Teleport](<https://devfeed.tech/sources/teleport.md>)

Topics: [ssh](<https://devfeed.tech/topics/ssh.md>), [Security](<https://devfeed.tech/topics/security.md>), [Authentication](<https://devfeed.tech/topics/authentication.md>), [remote access](<https://devfeed.tech/topics/remote-access.md>), [Regular expression](<https://devfeed.tech/topics/regular-expression.md>), [Library](<https://devfeed.tech/topics/library.md>)

Tags: [article](<https://devfeed.tech/tags/article.md>), [attacks](<https://devfeed.tech/tags/attacks.md>), [authentication](<https://devfeed.tech/tags/authentication.md>), [email](<https://devfeed.tech/tags/email.md>), [expression](<https://devfeed.tech/tags/expression.md>), [fail2ban](<https://devfeed.tech/tags/fail2ban.md>), [filter](<https://devfeed.tech/tags/filter.md>), [hardening](<https://devfeed.tech/tags/hardening.md>), [ip](<https://devfeed.tech/tags/ip.md>), [limit](<https://devfeed.tech/tags/limit.md>), [protection](<https://devfeed.tech/tags/protection.md>), [reduce](<https://devfeed.tech/tags/reduce.md>), [remote-access](<https://devfeed.tech/tags/remote-access.md>), [security](<https://devfeed.tech/tags/security.md>), [server](<https://devfeed.tech/tags/server.md>), [server-logs](<https://devfeed.tech/tags/server-logs.md>), [ssh](<https://devfeed.tech/tags/ssh.md>), [tcp](<https://devfeed.tech/tags/tcp.md>)

### AI overview

This tutorial presents four ways to harden SSH servers against brute-force attacks: limiting authentication attempts, using Fail2ban, and restricting SSH access with TCP wrappers. It also explains how Fail2ban filters server logs and responds to suspicious activity.

### Source excerpt

In this article, we explore and explain four ways to harden SSH from brute-force attacks to help improve security.

## Implementing Safe ActiveRecord Like Queries for Rails

DevFeed: [Implementing Safe ActiveRecord Like Queries for Rails](<https://devfeed.tech/articles/implementing-safe-activerecord-like-queries-for-rails-28243.md>)

Original publisher: [Read original article](<http://fuzzyblog.io/blog/rails/2019/11/11/implementing-safe-activerecord-like-queries.html>)

Author: Fuzzygroup

Published: 2019-11-11T00:00:00Z

Content type: tutorial

Language: en

Sources: [Scott Johnson](<https://devfeed.tech/sources/scott-johnson.md>)

Topics: [Rails](<https://devfeed.tech/topics/rails.md>), [SQL](<https://devfeed.tech/topics/sql.md>), [Databases](<https://devfeed.tech/topics/databases.md>)

Tags: [activerecord](<https://devfeed.tech/tags/activerecord.md>), [database](<https://devfeed.tech/tags/database.md>), [limit](<https://devfeed.tech/tags/limit.md>), [parameter](<https://devfeed.tech/tags/parameter.md>), [rails](<https://devfeed.tech/tags/rails.md>), [sql](<https://devfeed.tech/tags/sql.md>), [table](<https://devfeed.tech/tags/table.md>)

### AI overview

A Rails tutorial explains how to build safer ActiveRecord LIKE queries using Arel table fields and parameterized query construction. It demonstrates searching a Metric model's note field with filtering, ordering, limits, and pagination.

### Source excerpt

In any SQL based database, a like query is generally an SQL injection attack waiting to happen because the underlying sql statement looks like this: SELECT id FROM posts WHERE name LIKE '%foo%' Note: A 30 year old thank you goes out to InfoWorld and Joe Celko who beat into his reader's brains the concept of capitalizing SQL statements for better legibility. Thank you Joe. A seemingly solid StackOverflow post gives this recommendation: title = Model.arel_table[:title] Model.where(title.matches("%#{query}%")) Please note that Model needs to be replaced with the name of your table. Let's say that our table was named Metric and we have a normal simple_form object for Metric coming into our Rails app with a parameter named q and we have a real world Rails app with a limit clause and pagination. Here's how this would look: @q = params[:metric][:q] note = Metric.arel_table[:note] @metrics = current_user.metrics.where(note.matches("%#{@q}%")).order("date_created_at desc").limit(@limit).page(params[:page]) So: @q represents the incoming query note represents the field in our Metrics table that we want to search agains @metrics is the collection of data returned by the search and the where clause is "note.matches("%#{@q}%")" to find any instances of the term @q within the note field

## The Fourier Transform -- A Primer

DevFeed: [The Fourier Transform -- A Primer](<https://devfeed.tech/articles/the-fourier-transform-a-primer-40274.md>)

Original publisher: [Read original article](<https://www.jeremykun.com/2012/05/27/the-fourier-transform-a-primer/>)

Published: 2012-05-27T19:00:15Z

Content type: tutorial

Language: en

Sources: [Jeremy Kun](<https://devfeed.tech/sources/jeremy-kun.md>)

Topics: [fourier transform](<https://devfeed.tech/topics/fourier-transform.md>), [function](<https://devfeed.tech/topics/function.md>)

Tags: [analysis](<https://devfeed.tech/tags/analysis.md>), [convergence](<https://devfeed.tech/tags/convergence.md>), [convolution](<https://devfeed.tech/tags/convolution.md>), [duality](<https://devfeed.tech/tags/duality.md>), [fourier-analysis](<https://devfeed.tech/tags/fourier-analysis.md>), [fourier-transform](<https://devfeed.tech/tags/fourier-transform.md>), [function](<https://devfeed.tech/tags/function.md>), [limit](<https://devfeed.tech/tags/limit.md>), [mathematics](<https://devfeed.tech/tags/mathematics.md>), [primer](<https://devfeed.tech/tags/primer.md>)

### AI overview

This primer introduces the Fourier transform as a limiting case of the Fourier series for functions without periodic behavior. It develops the transform from intuitive definitions and then addresses convergence more rigorously using distributions.

### Source excerpt

In our last primer we saw the Fourier series, which flushed out the notion that a periodic function can be represented as an infinite series of sines and cosines. While this is fine and dandy, and quite a powerful tool, it does not suffice for the real world. In the real world, very little is truly periodic, especially since human measurements can only record a finite period of time. Even things we wish to explore on this blog are hardly periodic (for instance, image analysis).