Text DB engine powering vk.com and Telegram

Some context: the DB in the post is mentioned as a crucial piece of VK and Telegram infrastructure in a recent post [1] by a disgruntled Telegram C-level ex-employee. The post itself is in Russian and AFAIK isn't translated to English yet. It will be, eventually, as it provides huge insight into Telegram/VK inner workings.

Some excerpts:

- Telegram is indeed still developed in Saint-Petersburg, Russia;

- At some point Telegram servers were moved from London to some undisclosed European capital in vans [2][3] without any documents, somehow bypassing customs;

- Telegram's Russian company filed a $1.7M lawsuit against ex-employee (who penned that post) for "NDA breach". Breach in question: he mentioned his position in a company in his Facebook bio and used corp chat screenshots in court while appealing his firing.

[1]: https://medium.com/@anton.rozenberg/friendship-betrayal-clai...

[2]: https://cdn-images-1.medium.com/max/800/1*cPwKcx7Vyhk0Kss-vC...

[3]: https://cdn-images-1.medium.com/max/800/1*Bg3_F2VJbtbZ2hs75v...

So vk.com uses plaintext as a storage medium for their files?