intro
Have you heard of the Schrodinger’s cat concept? If you’re a physicist, you’ve surely did – it’s a thought experiment that aims to illustrate a paradox of a cat being both dead and alive simultaneously. Sounds interesting, right?
The Schrodinger’s cat concept is not news – what may be new, however, is the fact that the same concept can be applied inside of the SQL world too. Surprised? Don’t be – databases can really disappear one day and appear the other. Just ask any seasoned DBA for his horror stories…
Coming back to the Schrodinger’s cat, answers to such issues are frequently required to properly solve SQL leetcode problems, and they also play a role in many SQL interviews. Read on – we’ll tell you why in a second!
SQL Problems and the Schrödinger's Cat
To illustrate the schrodinger’s cat-related SQL problems, we need to re-introduce you to ACID once again: ACID are the properties that warrant data validity despite power outages or any failures related to data. Frequent readers of our blog may remember us saying that ACID may be implemented differently in different database management systems – the concept remains the same.
Alright, so what does Schrodinger have to do with your database supporting ACID? To answer that question, you need to think of everything the other way around: if an operation you’ve ran previously failed and you’re not being able to act on it, you may be dealing with a Schrodinger’s table in your database instances. Here’s how it works:
For additional confirmation, visit the data directory of your database instance. If you’re using MySQL server, that’s most likely /var/lib/mysql/data. Are you able to see the files having .frm and .ibd extensions? .frm means data definition, and .ibd files store the data of the tables inside of them. Weird? Should be.
Fixing the Paradox
What a weird cat, huh? Time to get it out of your database. Thankfully, it’s rather easy to do so:
If everything seems too complex, don’t fret – you can also perform a global cleanup just as easily. Read on.
Global Cleanup
To perform a global cleanup of your database, perform these steps:
Your database is now fresh – woohoo!
SQL Clients and Avoiding Paradoxes
If you’ve been facing the Schrodinger’s cat or any other paradox in your database instances in the recent months, you already know how confusing it can become; to avoid such paradoxes, make sure to use top-rated SQL clients like the one provided by DbVisualizer. DbVisualizer is a powerful SQL client that will not only help you write SQL queries, but also help you visualize their output in a beautiful manner, enable you to secure your data with a master password if you so desire, help you organize your work in your personal workspace and put your messy data management back into your hands – start using it today.
Summary
In this blog, we’ve walked you through the so-called Schrodinger’s cat paradox in database management systems. While to some it seem weird and troublesome, the paradox can cause real problems to your databases both now and in the future, so for it not to be a headache for you or your staff, ensure that your running transactions are not interrupted, and if they are, know the steps you should perform next.
Visit our blog later on for updates, and until next time!
