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TimescaleDB

When working with time series data like stock prices, website traffic, or error logs, the volume of data grows rapidly over time. In traditional relational databases like PostgreSQL and SQL, this can lead to slower query performance as the dataset becomes larger.

One alternative is to use NoSQL databases, but they come with their own challenges, such as lack of strong ACID compliance, complex querying, and difficulties in handling structured relational data.

TimescaleDB, which is built on top of PostgreSQL, offers a powerful solution by introducing hypertables - a special type of table optimised for time series data. Hypertables enable faster read and write operations, automatic partitioning, and efficient data compression. Additionally, TimescaleDB provides advanced analytical functions, making it easier to perform complex queries for reporting, trend analysis, and forecasting. This makes it a great choice for applications that require efficient storage and analysis of large-scale time series data.

#databases #time_series_data #timescale_db #postgres

We can't use turbo frame for table rows, because html doesn't allow external tag like turbo frame inside the table.

The workaround this is to just have unique id for element you want to modify and use turbosteam to modify only that element.

#rubyonrails #turbo #turboframes #spa

in ruby https://nil.to|nil.to_i => 0 & https://nil.to|nil.to_f => 0.0
#ruby, #nil-conversion

Steps to merge one repo into another

Step 1: Clone Repo1 locally

git clone  repo1
cd repo1

Step 2: Fetch all the branches and commits from Repo2

git remote add repo2 
git fetch repo2

Step 3: Create a branch

git checkout -b merge-repo2

Step 4: Merge keeping full history

git merge --allow-unrelated-histories repo2/main (Since the repositories have separate histories, this option allows Git to combine them, potentially requiring manual conflict resolution)

Step 5: Resolve Merge Conflicts

git add .
git commit -m "Resolved merge conflicts"

#git

pagy_array This method is the same as the generic pagy method, but specialized for an Array.

require 'pagy/extras/array'
@pagy, @items = pagy_array(an_array)

#CU6U0R822 #ruby

```
pagy_array

each_with_object is an enumerable method in Ruby that allows you to iterate over a collection while building up an object (like an array or hash). Unlike map, which creates a new array, each_with_object lets you modify an existing object in a single pass.

Syntax

collection.each_with_object(initial_object) do |item, object|
  # Modify the object inside the block
end

• collection: The array or enumerable you're iterating over.
• initial_object: The object that will be modified (e.g., {} for a hash or [] for an array).
• item: The current element in the iteration.
• object: The object that accumulates the results.
Example Usage
Using each_with_object with a Hash

numbers = [1, 2, 3, 4, 5]
squares = numbers.each_with_object({}) do |num, hash|
  hash[num] = num**2
end

puts squares
# Output: {1=>1, 2=>4, 3=>9, 4=>16, 5=>25}

Why use each_with_object?
• Avoids the need to initialize an empty {} before the loop.
• Eliminates the need to return the object explicitly.

#CU6U0R822 #ruby

When to use collection_select over select in rails
Use collection_select when you need to populate a dropdown with a collection of ActiveRecord objects. It is built on top of select and provides a convenient way to display object attributes instead of a simple array of strings.
select is used for manually defining options, typically from an array of strings or key-value pairs.
collection_select is specifically designed for selecting records from an ActiveRecord collection, making it useful when working with database associations.

Rake tasks in Rails let you run custom scripts from the command line.
You can define your own tasks inside the lib/tasks directory.

How to Create a Custom Rake Task

1. Create a new .rake file in lib/tasks/

touch lib/tasks/custom_tasks.rake

Define the task inside the file:

namespace :custom do
  desc "Say hello from a custom rake task"
  task :hello do
    puts "Hello from custom Rake task!"
  end
end

Run the task from the terminal:

bin/rake custom:hello

Use :environment if your task interacts with the database or models

#CU6U0R822 #rake

The inverse_of option in ActiveRecord helps Rails recognize bidirectional associations in memory, reducing redundant database queries.
For example:

class Employee < ApplicationRecord
  belongs_to :department, foreign_key: 'department_code', primary_key: 'code', inverse_of: :employees
end

class Department < ApplicationRecord
  has_many :employees, foreign_key: 'department_code', primary_key: 'code', inverse_of: :department
end

Why Use inverse_of?
• Prevents extra queries when accessing related objects
• Keeps objects in memory, improving performance
• Ensures associated objects reference the same instance
Without inverse_of, Rails may reload the association unnecessarily:

employee = Employee.first
department = employee.department  # Triggers a SQL query
department.employees.include?(employee)  # Without `inverse_of`, this could trigger another query

With inverse_of, Rails avoids the extra query because it knows department.employees already includes employee

#CU6U0R822 #active_record