tomfun

Article Introduction: Navigating Database Technologies for Hierarchical and Social Network Data Management

Overview

In today's digital landscape, efficient data management is pivotal, especially when dealing with complex structures like trees and graphs. These structures, foundational in computer science, dictate how data is stored, accessed, and manipulated across various platforms, from social networks to organizational systems. This article provides a comprehensive exploration of tree and graph structures and their implementation in different database systems, assessing their effectiveness in contexts ranging from hierarchical data management in traditional databases to sophisticated relationship mapping in graph databases.

Tree and Graph: A Comparative Study of Data Structures

Tree Structure

tomfun

const printValues = (data) => {
    const getType = (value) => {
        if (Array.isArray(value)) return 'array';
        if (null === value) return 'null';
        return typeof value;
    };
    const initResult = () => ({ _type: new Set([]), _values: new Set() })

    const updateValues = (result = initResult(), item) => {
        const type = getType(item);

tomfun

end-to-end encryption

In order to use end-to-end encryption, it is enough to use a browser extension - it uses open pgp - open source for encryption and keys and just inserts a button to gmail :)

https://youtu.be/aAXIqnjbc-M?t=106 Mymail-Crypt for Gmail at chrome store

quite radical, simple, but it can fall off :)

there is a more reliable way, but you have to manually encrypt it - another extension

tomfun

Pessimistic Locking in Node.js with TypeORM

In this article, we will explore pessimistic locking, its main aspects, and how to implement it in Node.js using TypeORM. Pessimistic locking is a strategy to prevent concurrent access to a resource by obtaining exclusive access to the resource before making any changes. This approach ensures that other transactions cannot modify the locked resource until the lock is released.

We will use a practical example to demonstrate how to implement pessimistic locking in a Node.js application using the TypeORM library. Our example will focus on a payment processing scenario, where multiple processes might attempt to update the status of a payment concurrently.

tomfun

https://raspberrypi.stackexchange.com/questions/8265/btrfs-root-filesystem-on-raspbian

sudo apt install btrfs-progs initramfs-tools

'btrfs' | sudo tee -a /etc/initramfs-tools/modules

sudo mkdir -p /etc/initramfs-tools/hooks ; sudo mkdir -p /etc/initramfs-tools/scripts/local-premount ; sudo cp /usr/share/initramfs-tools/hooks/btrfs /etc/initramfs-tools/hooks ; sudo cp /usr/share/initramfs-tools/scripts/local-premount/btrfs /etc/initramfs-tools/scripts/local-premount; sudo chmod +x /etc/initramfs-tools/hooks/btrfs /etc/initramfs-tools/scripts/local-premount/btrfs

https://forums.raspberrypi.com/viewtopic.php?t=10532&sid=506b6601ef85b73e2e6cafc95f4636c6&start=50

tomfun

Good ppa`s

• add-apt-repository ppa:nextcloud-devs/client
• add-apt-repository ppa:phoerious/keepassxc
• add-apt-repository ppa:git-core/ppa
• add-apt-repository ppa:andol/curl-http2

Linux mint base ubuntu table

Mint	Ubuntu	Proof

tomfun

https://medium.com/python-programming-at-work/multiple-python-versions-with-pyenv-266e1801ff3d

2. pyenv curl -L https://github.com/pyenv/pyenv-installer/raw/master/bin/pyenv-installer | bash follow instructions and add PYENV_ROOT

edit  ~/.bashrc

Add this to end

export PYENV_ROOT="$HOME/.pyenv"

tomfun

import { generateSequence } form './simple'

class NumberTransfrormer {
    transform = async function*(gen: AsyncGenerator<number>) {
        for await (const n of gen) {
            yield n * 2;
        }
    }
}

tomfun

{
    "AWSTemplateFormatVersion": "2010-09-09",
    "Parameters" : {
        "MainDomainName": {
            "Description": "public pretty FQDN for cloudfront",
            "Type": "String",
            "Default": "example.com"
        },
        "AcmCertificateArn": {
            "Description": "AWS certificate ID for cloudfront",

tomfun

Check SSH security

• online
  • https://www.ssh-audit.com/
  • https://sshcheck.com/
• python script https://github.com/jtesta/ssh-audit
• value of such test https://hackerific.net/2017/04/23/ssh-audit---a-tool-for-checking-ssh-server-security/
• steps to do https://www.ssh-audit.com/hardening_guides.html#ubuntu_18_04_lts