Save the queries, cache your objects! Optimizing Django

A quick word on caching before we dive into it…

With the use of a cache, it is possible to cut an immense amount of redundant DB queries. I won’t try to explain the inner mechanics of caching myself as there are plenty of articles out there explaining how caching works. The good thing is that Django supports multiple types of caches, from the small-scale file-based cache to the enterprise-level Redis, and for the purpose of this guide, I will skip the details to implementing those.

If you want more information on how to setup Redis in Django, check out this article which explains just that. Django also has a guide for setting your server up to access a custom cache, among other things.

Now what can caching help you with?

Let’s start with the per-site caching. Per-site caching is the simplest sort of caching that can be done for your server’s website. If your server serves static webpages, this is perfect for you.

With per-site caching, there isn’t too much SQL to speak of in simple use case scenarios, so I don’t have too much to add for per-site caching. However, per-site caching does remove the I/O workload of loading files from memory, or even from a CDN, allowing the server to load said webpages from cache instead.

However, Django also offers per-view caching, which can produce tangible savings in the SQL front. If your view serves data that is relatively static, this is great for performance, especially if the view is accessed frequently. Furthermore, if your view serves a custom result per logged-in user, you can include a vary_on_headers decorator to cache per user, although this has its drawbacks (it is quite overkill for common use scenarios).

Finally, you can access Django’s low-level cache to cache responses, which is rather powerful and directly applicable enough to explore…

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Save the queries, cache your objects! Optimizing Django
Arvel  Parker

Arvel Parker

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How to Find Ulimit For user on Linux

How can I find the correct ulimit values for a user account or process on Linux systems?

For proper operation, we must ensure that the correct ulimit values set after installing various software. The Linux system provides means of restricting the number of resources that can be used. Limits set for each Linux user account. However, system limits are applied separately to each process that is running for that user too. For example, if certain thresholds are too low, the system might not be able to server web pages using Nginx/Apache or PHP/Python app. System resource limits viewed or set with the NA command. Let us see how to use the ulimit that provides control over the resources available to the shell and processes.

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MEAN Stack Tutorial MongoDB ExpressJS AngularJS NodeJS

We are going to build a full stack Todo App using the MEAN (MongoDB, ExpressJS, AngularJS and NodeJS). This is the last part of three-post series tutorial.

MEAN Stack tutorial series:

AngularJS tutorial for beginners (Part I)
Creating RESTful APIs with NodeJS and MongoDB Tutorial (Part II)
MEAN Stack Tutorial: MongoDB, ExpressJS, AngularJS and NodeJS (Part III) 👈 you are here
Before completing the app, let’s cover some background about the this stack. If you rather jump to the hands-on part click here to get started.

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Ahebwe  Oscar

Ahebwe Oscar

1620185280

How model queries work in Django

How model queries work in Django

Welcome to my blog, hey everyone in this article we are going to be working with queries in Django so for any web app that you build your going to want to write a query so you can retrieve information from your database so in this article I’ll be showing you all the different ways that you can write queries and it should cover about 90% of the cases that you’ll have when you’re writing your code the other 10% depend on your specific use case you may have to get more complicated but for the most part what I cover in this article should be able to help you so let’s start with the model that I have I’ve already created it.

**Read More : **How to make Chatbot in Python.

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let’s just get into this diagram that I made so in here:

django queries aboutDescribe each parameter in Django querset

we’re making a simple query for the myModel table so we want to pull out all the information in the database so we have this variable which is gonna hold a return value and we have our myModel models so this is simply the myModel model name so whatever you named your model just make sure you specify that and we’re gonna access the objects attribute once we get that object’s attribute we can simply use the all method and this will return all the information in the database so we’re gonna start with all and then we will go into getting single items filtering that data and go to our command prompt.

Here and we’ll actually start making our queries from here to do this let’s just go ahead and run** Python manage.py shell** and I am in my project file so make sure you’re in there when you start and what this does is it gives us an interactive shell to actually start working with our data so this is a lot like the Python shell but because we did manage.py it allows us to do things a Django way and actually query our database now open up the command prompt and let’s go ahead and start making our first queries.

#django #django model queries #django orm #django queries #django query #model django query #model query #query with django

CentOS Linux 8.2 Released and Here is How to Upgrade it

CentOS Linux 8.2 (2004) released. It is a Linux distribution derived from RHEL (Red Hat Enterprise Linux) 8.2 source code. CentOS was created when Red Hat stopped providing RHEL free. CentOS 8.2 gives complete control of its open-source software packages and is fully customized for research needs or for running a high-performance website without the need for license fees. Let us see what’s new in CentOS 8.2 (2004) and how to upgrade existing CentOS 8.1.1199 server to 8.2.2004 using the command line.

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systemctl List All Failed Units/Services on Linux

Is there is a command to print list all failed units or services when using systemd on Linux? Can you tell me the systemctl command to list all failed services on Linux?

This quick tutorial explains how to find/list all failed systemd services/units on Linux operating systems using the systemctl command.

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