The Digital Commander

ICT practitioner | Web technologist | data analyst | Researcher

Sports passionate
God Always

[Linux Inside: The Ideal Blog for Sysadmins & Geeks @tecmint]

Most sysadmins expose SSH on every server they manage and spend their time hardening each one individually.

There is a better architecture. One hardened entry point. Everything else is invisible from the internet.

In Chapter 34 of our SSH course, you will learn how bastion hosts work, how to configure ProxyJump for transparent multi-hop connections, and how to build a secure single-entry-point infrastructure where SCP, rsync, and port forwarding all work through the bastion automatically.

Read it here → https://t.co/38Wvg6G1cM

Follow @tecmint for new #SSH chapters every week.

[Linux Inside: The Ideal Blog for Sysadmins & Geeks @tecmint]

Quick Linux Tip #11

Need to find exactly when you ran a command without scrolling endlessly through shell history?

First, enable timestamps:

$ export HISTTIMEFORMAT="%F %T "

Then search your history:

$ history | grep ssh

This lets you quickly find commands and see the exact date and time they were executed.

For even faster searching, press Ctrl+R and start typing. Bash will search your history interactively as you type.

Once you know these shortcuts, you'll never spam the up arrow again.

Follow @tecmint for more #Linux tips

[Linux Inside: The Ideal Blog for Sysadmins & Geeks @tecmint]

Quick Linux Tip #12

Ever wondered which files were changed on your system recently?

Here’s a simple way to check it in Linux:

find /etc -type f -mtime -30

This shows all files inside /etc that were modified in the last 30 days.

So instead of opening files one by one, Linux quickly shows you what changed.

The -type f part means it will only show files (not folders), and -mtime -30 means “modified less than 30 days ago”.

Follow @tecmint for more #Linux tips

[Samay @Samaytwt]

Be honest

As a developer, which database is worth in the AI era?

[NOVA @Its_Nova1012]

Two backend engineers solved the same problem.

Design A 👇

SELECT *
FROM users
WHERE email = ?

Design B 👇

SELECT *
FROM users
WHERE LOWER(email) = LOWER(?)

Which query would you ship to production?

[KrunalSinh Sisodia @krunalbuilds]

@Its_Nova1012 A.

WHERE email = ?
uses the index efficiently.

WHERE LOWER(email) = LOWER(?)
can bypass the index and trigger a table scan.

Rule: Don’t apply functions to indexed columns unless you have a functional index.

[The Digital Commander @BenardKE]

@JumiaKenya
Is it possible to change the pickup station for a particular order.
I mistakenly picked a station too far from where i should have
I was not expecting my order to be delivered to a station of close proximity

if not, just cancel it
347193517

[The Digital Commander @BenardKE]

@JumiaKenya order #385279978 is not the same as order #331347287

I am not happy about order #331347287 on the general quality of the item,
I would wish to return it, kindly share the procedure

[The Digital Commander @BenardKE]

@Safaricom_Care
Advice on how i can retrieve mpesa statement from january 2022 to april 2022

[Shalini Tewari @maybeshalinii]

Day 6 of MongoDB

Indexing and Performance
Indexes are crucial for optimizing query performance in MongoDB. They help speed up the retrieval of documents by reducing the amount of data MongoDB needs to scan to fulfill a query. Today, we'll dive into the basics of indexing, different types of indexes, and strategies for optimizing query performance.

Indexing Basics

What is an Index?
An index in MongoDB is a data structure that improves the speed of data retrieval operations on a collection. Think of an index as a table of contents in a book—it allows MongoDB to quickly locate the required data without scanning the entire collection.

How Indexes Work:

- When you query a collection, MongoDB uses an index to locate the documents that match the query criteria.
- Without an index, MongoDB must perform a collection scan, meaning it reads every document in the collection to find the matching documents.

creating an index:
db.users.createIndex({ username: 1 });

This creates an ascending index on the `username` field in the `users` collection. The `1` specifies ascending order, while `-1` would specify descending order.

[Aryan Rakib @tec_aryan]

14 Hidden AI Websites That Will Blow Your Mind 🤯

🔖Save Them Now Before You Forget!

[Shalini Tewari @maybeshalinii]

Day 2 of SQL

- Components of SQL
- Retrieving specific columns with SELECT
- Using aliases for column names

Components of SQL:

- Data Definition Language (DDL):
Used for defining and modifying the structure of the database schema.
Includes commands like CREATE, ALTER, DROP, TRUNCATE.

- Data Manipulation Language (DML):
Used for manipulating data within the database.
Includes commands like SELECT, INSERT, UPDATE, DELETE.

- Data Control Language (DCL):
Used for controlling access to data within the database.
Includes commands like GRANT and REVOKE.

- Transaction Control Language (TCL):
Used for managing transactions within the database.
Includes commands like COMMIT, ROLLBACK, SAVEPOINT.

- Data Query Language (DQL):
Primarily used for querying data from the database.
Includes commands like SELECT.

[Hamza Khalid @humzaakhalid]

I Surf the whole internet daily

Here are 10 incredibly useful Websites you probably didn't know existed:

Trust me, You will bookmark all these 🔖

[The Digital Commander @BenardKE]

@HerbalistChief Kindly recommend any treatment for baldness, head hair

[Bishal Nandi @LearnWithBishal]

7 useful websites you need to know in 2024:

(🔖Save it for later)

[James Lucas @JamesLucasIT]

Thread of places that don't look real 🧵

1. Sea of Japan, where snow, beach & sea meet

[James Lucas @JamesLucasIT]

Thread of before and after photos 🧵

1. Chichen Itza in 1892 and now