Monday, March 20, 2017

Best way for effective Postgresql database backups

Unfortunately the Internet is littered with ineffective methods of backing up your precious PostgreSQL database. Most methods use the pg_dumpall technique - this is inherently faulty for mission critical databases as it only creates plain text backups which would limit the restore options.

A better way is to use custom format backups coupled with global data backups (such as user accounts, permissions, etc):

Friday, March 03, 2017

Deploying Apps on Github Pages

While is a great way to simulate web applications while in development, I find it more convenient to eventually deploy the Free Code Camp challenges to Github Pages. Examples of web applications I have deployed so far:
  1. Wikipedia Viewer
  2. JS Calculator
  3. Tic Tac Toe Game
  4. Pomodoro Clock
It’s really simple. Once you create a github pages account and create a new repository, just follow these steps to deploy the app on github pages:

Traverse JSON trees

I believe that knowing how to traverse JSON trees is an important skill to master, particularly when designing applications that consume complex JSON structures through API requests.

When I recently started playing around the epynomous Wikipedia Viewer challenge on Free Code Camp, traversing the wikipedia API tree was an important first step. While there are many techniques, I decided to go for a recursive function approach. Pay attention however as Javascript creates a stack for each recursive call...

The way this works is straightforward:

  1. For each JSON object determine whether it is a defined (bang bang!!) object.
  2. If it is an object, recursively call the function to traverse it.
  3. If it is not an object (example: array, string, value), then it must be a leaf node!

Take the Wikipedia API JSON tree as an example which looks like this:

The traverse function will iterate through each object, but for the sake of this example, scanning through the first object of the Pages object will look like this: