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xoelop / Getting help with a ClickHouse problem — issues & support tickets.md
Last active July 24, 2026 14:20

Getting help with a ClickHouse problem — issues & support tickets

When we hit a ClickHouse problem we can't solve on our own — almost always a bug or something that doesn't behave as the docs describe, occasionally a genuine question — this is the playbook for asking for help in a way that actually gets it solved fast.

The whole strategy rests on one idea: make it trivially easy for someone who has never seen our data to help us. The more of our production context they'd need, the slower (or more impossible) the help.

The golden rule: a minimal, reproducible example

Always try to ship a self-contained, minimal reproduction. If someone can paste it and see the bug themselves, anyone — ClickHouse staff and the wider community — can jump in. If instead they'd need our exact data, our schema, or access to our database, help gets much harder to get.

@xoelop
xoelop / clickhouse-query-cost-attribution-gist.md
Created July 7, 2026 10:53
ClickHouse query cost attribution with log_comment and system.query_log

How to attribute ClickHouse query cost by endpoint, user/team and code path

This is the setup I would build if I wanted to answer these questions:

  1. How many ClickHouse cores do we need?
  2. What rate limit makes sense per endpoint, customer, or use case?
  3. What is the max QPS ceiling we can safely give?
  4. Which queries, users/teams, endpoints, and backend methods are using the most CPU?

Load tests against your own API are still useful, but this gives you the base database cost of each query shape in production.

@xoelop
xoelop / Xoel.bttpreset
Last active June 8, 2025 11:15
{
"BTTPresetCreatorNotes" : "",
"BTTPresetInfoURL" : "",
"BTTPresetName" : "Xoel",
"BTTPresetColor" : "205.206320, 241.230000, 106.141200, 255.000000",
"BTTGeneralSettings" : {
"BTTShowBTTWhenControlStripHidden" : true,
"BSTTopMissionControlTreshold" : 34,
"BTTDrawingAreaWidth" : 915,
"BTTNotchBarNotchWidgetModeShowMiniMenubar" : true,
@xoelop
xoelop / .pre-commit-config.yaml
Last active March 12, 2025 11:12
script to replace secrets from one or multiple files, given a .env file where they're stored and pre-commit hook to run it before each commit
repos:
# Local hooks
- repo: local
hooks:
- id: env-var-replacer
name: Replace sensitive values with env variables
description: Replace actual values from .env with their variable names
entry: scripts/env_var_replacer.sh .env blur
language: script
@xoelop
xoelop / generate_commit_message.py
Created February 21, 2025 07:44
Generates a commit message for the staged changes in git, allowing us to pass custom instructions on how the message should look like and copies the commit message to the clipboard
# import pyperclip
import argparse
import os
import subprocess
import openai
from dotenv import load_dotenv
load_dotenv()
@xoelop
xoelop / feature flags jobs sample.csv
Created September 12, 2023 16:16
We can make this file beautiful and searchable if this error is corrected: It looks like row 2 should actually have 30 columns, instead of 24 in line 1.
job_title,url,company,location,remote,salary_string,min_annual_salary_usd,max_annual_salary_usd,salary_currency,countries,country,cities,continents,technology_names,date_posted,seniority,country_codes,created_at,final_url,normalized_title,manager_roles,matching_phrases,matching_words,company_url,company_linkedin,industry,company_size,probability_actual_domain_found,company_url_source,logo
Pleno Engenheiro de Software Java | Kotlin,https://indeed.com/viewjob?jk=3326b0400a6a9485,Impulso,"Remoto, Brazil",false,R$ 13.600 - R$ 14.400 por mês,32979.02,34918.97,BRL,,Brazil,,,"Cloud, Java, AWS, Amazon Web Services, Docker, Spring, Kubernetes, BEM, PostgreSQL, Spring Boot, Kotlin, Postgres",2023-09-11,Mid-Level,BR,2023-09-12T06:32:18.600117+00:00,https://impulso.team/en/profissionais/oportunidade/1938,engenheiro de software,,"É super importante ter conhecimento no uso de feature flags / feature toggles, DDD, Continuous integration e Continuous delivery, qualidade de código e testes automatizados",feature flags,https:
@xoelop
xoelop / jobs_sample.csv
Created August 29, 2023 10:09
We can make this file beautiful and searchable if this error is corrected: Unclosed quoted field in line 1.
"113375236","https://indeed.com/viewjob?jk=9b8f0538f79216b3","Asistente- Gestión De Documentos","Banco General, S.A.","PROPOSITO DEL CARGO Gestionar, clasificar, digitalizar y ordenar un conjunto de documentos que son necesarios para conservar una base de datos de los clientes; cumpliendo las normas y procedimientos del Banco, el Código de Ética y Valores, las normas y procedimientos de uniforme y de imagen del Banco; y así mantener un control de la producción de información, como de su manejo y edición. FUNCIONES GENERALES Archivo de carpeta o documentos de portafolio de inversión Preparar documentos de cuentas de inversión local o internacional de persona natural o jurídica para el proceso de digitalización Preparar documentos de cuentas bancarias de persona natural o jurídica para el proceso de digitalización Digitalizar cuentas bancarias y cuentas de inversión local o internacional de persona natural o jurídica Rearmado de carpeta de cuentas de inversión local o internacional de persona natural o jurídica
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xoelop / newsletter_data.csv
Created August 16, 2023 12:18
We can make this file beautiful and searchable if this error is corrected: Unclosed quoted field in line 2.
name_text,newsletter_tags_list_option_category_keywords,profile_image_image,starting_price_number,subscribers_number,Slug,click_rate_number,newsletter_freq_option_newsletter_frequency,open_rate_number,status_option_newsletter_status,url_text,newsletter_other_category_text,newsletter_crosspromotion_option_cross_promotions,long_summary_text,owner1_list_user,verified_date,Modified Date,short_summary_text,facebook_url_text,twitter_url_text,newletter_category_option_category,flytier_url_text
Codementor's Newsletter,"['tech', 'productivity']",//s3.amazonaws.com/appforest_uf/f1658204152516x482178286177161700/NewLogo_circle_white%20%281%29.png,3000,471771,codementors-newsletter,0.12,week,0.21,approved,https://www.codementor.io/,Education,i_m_open_to_cross_newsletter_sponsorships0,"🚩 Codementor is a newsletter that helps developers learn and grow in programming knowledge through curated events and community articles.
⌛️ Every week, Codementor sends a newsletter with upcoming virtual events and featured articles by o
@xoelop
xoelop / tinybird-requests.json
Created December 22, 2022 12:31
Retool dashboard to explore queries to any pipe of your Tinybird account
{
"uuid": "60799e3a-81e6-11ed-8e5b-1377772fbf58",
"page": {
"id": 115259211,
"data": {
"appState": "[\"~#iR\",[\"^ \",\"n\",\"appTemplate\",\"v\",[\"^ \",\"isFetching\",false,\"plugins\",[\"~#iOM\",[\"textInputToken\",[\"^0\",[\"^ \",\"n\",\"pluginTemplate\",\"v\",[\"^ \",\"id\",\"textInputToken\",\"type\",\"widget\",\"subtype\",\"TextInputWidget2\",\"namespace\",null,\"resourceName\",null,\"resourceDisplayName\",null,\"template\",[\"^3\",[\"spellCheck\",false,\"readOnly\",false,\"iconAfter\",\"\",\"showCharacterCount\",false,\"autoComplete\",false,\"maxLength\",null,\"hidden\",false,\"customValidation\",\"\",\"patternType\",\"\",\"hideValidationMessage\",false,\"textBefore\",\"\",\"validationMessage\",\"\",\"textAfter\",\"\",\"showInEditor\",false,\"showClear\",false,\"pattern\",\"\",\"tooltipText\",\"\",\"labelAlign\",\"left\",\"formDataKey\",\"{{ self.id }}\",\"value\",\"\",\"labelCaption\",\"\",\"labelWidth\",\"33\",\"autoFill\",\"\",\"placeholder\",\"Enter value\",\"la
@xoelop
xoelop / create_heroku_jobs.py
Created November 8, 2022 17:06
Script to create jobs in the Heroku Scheduler programatically
import json
import requests
from dotenv import load_dotenv
load_dotenv(override=True)
import os
for i in range(3, 52):