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by ahachete 1681 days ago
> I am estimating that your database space isn't MySQL, which is just fine of course.

You are absolutely right :) My background is strongly on Postgres, you can see from my profile more information if you want to.

So yes, I apologize if some of my questions are not applying or become to obvious for cases that are MySQL-based. But for the most part, I believe principles of operation are the same.

> [other comments]

As mentioned, thank you very much for the detailed information. This completes the picture that I was looking for. I will definitely go in more detail for some of the links provided.

This principle of operation is not too different from something I proposed to a Postgres project some time ago (https://github.com/cybertec-postgresql/pg_squeeze/issues/18). This tool indeed is conceptually pretty similar. It's a shame that supporting schema changes is not part of their focus at this point. It wouldn't do throttling either, but it shouldn't be a difficult feature to add, I guess.

For other users here that may be interested in the Postgres world, there are two tools that perform similar operation (creating a shadow table and filling it in the background), but are both focused on rewriting the table to avoid bloat, rather than for doing a schema migration:

* pg_repack (https://reorg.github.io/pg_repack/): the most used one, relies on triggers * pg_squeeze: already mentioned, uses logical replication

1 comments

Heh, and in the MySQL space, we use a "trivial" online schema schema migration (that has no actual schema changes) to avoid table bloat :)