I sail the high seas of the Lemmyverse, posting snarky + Lefty comments

  • 0 Posts
  • 18 Comments
Joined 2 years ago
cake
Cake day: May 7th, 2023

help-circle




  • I’m a dev but not very good at mobile.

    I can promise you that a lot of engineering work went into making the tiktok scrolling experience so smooth. Part of the trick is having a good enough algorithm that the user wants to watch the majority of served videos.

    Another huge part of it is having lightning fast content distribution and aggressive “prefetching” of the next videos in the feed.

    I don’t want to discourage you but I also don’t want you to be caught off guard by the difficulty. Do you want to make this bad enough to give it your nights and weekends for a year?


  • ELI5: a database is the “memory” of a program.

    Every piece of data that any software uses almost certainly comes from and goes to multiple databases.

    Once the data is stored, you can execute “queries” to have powerful access to update many records at a time, read particular records based on their relationship to other records, and so much more.

    Your bank balances, your purchase history, your emails, every part of your digital life is almost certainly spread across a constellation of databases.

    Bonus Fediverse content:

    Lemmy itself uses the Postgres database extensively. Posts, users, comments, votes and more are all individually stored in the database.

    Mastodon also uses Postgres. If a post goes up on Lemmy, and a Mastodon server is federated with it, the Lemmy server will send out a HTTP request to the Mastodon server containing the contents of the post. The Mastodon server will use this information to write its own record of the post in its own database.

    Regarding your question about VMs: You can run a database inside a VM, or give the VM access to an outside database via queries, or both! You might run SQLlite (a small and excellent embedded database) on the VM to track its local state, while also running queries against a large postgres database to synchronize with other services in the cluster.