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Show HN: Stellar – Git for PostreSQL and MySQL

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Re: Show HN: Stellar – Git for PostreSQL and MySQL

#21

Post by obsession »

falcolas wrote: post #17

So, it appears to just copy tables around within the database. I wouldn't want to use this on a DB over a few MB in size. Sure, restores are "fast" (a table rename), but copies are not so much. I can't imagine this would be kind to a production database (lots of cleanup from copied & deleted tables), and would consume a lot more space than a gripped logical backup of the tables in question.

I have regularly used this with database that's nearing 1000 megabytes. I don't particularly mind slow snapshotting because my workflow is more about restoring database back to baseline than taking copies.

Please don't use this for production. It is not stable enough and you only end up with lost data.

Re: Show HN: Stellar – Git for PostreSQL and MySQL

#23

Post by crad »

Maybe I'm missing something, but I didn't see anything with regard to indexes, users, stored procedures, views or what not.

Seems like it's for table schema snapshotting in a database without any external storage.

Browsing through the code, I see that it's highly table centric using SQLAlchemy.

Re: Show HN: Stellar – Git for PostreSQL and MySQL

#24

Post by masklinn »

michaelmior wrote: post #14
lucian1900 wrote: post #5

This sort of thing is useful, but already supported by Postgres through transactional DDL. Migrations that fail will have their transaction reverted.

Suppose I'm working on a new feature branch and I run a bunch of migrations and add new data. Then I need to go make a bug fix on the master branch. Using Stellar, I could just take a snapshot before starting my feature branch, restore the DB state, do my bug fix, then go back to the DB as it was in my feature branch. I haven't tried Stellar yet, but this seems like a scenario where it would be useful. (And definitel…

You could use schemas or multiple databases for that.

Re: Show HN: Stellar – Git for PostreSQL and MySQL

#26

Post by falcolas »

obsession wrote: post #21
falcolas wrote: post #17

So, it appears to just copy tables around within the database. I wouldn't want to use this on a DB over a few MB in size. Sure, restores are "fast" (a table rename), but copies are not so much. I can't imagine this would be kind to a production database (lots of cleanup from copied & deleted tables), and would consume a lot more space than a gripped logical backup of the tables in question.

I have regularly used this with database that's nearing 1000 megabytes. I don't particularly mind slow snapshotting because my workflow is more about restoring database back to baseline than taking copies. Please don't use this for production. It is not stable enough and you only end up with lost data.

Why not use a binary backup method? Faster to backup and restore.

Re: Show HN: Stellar – Git for PostreSQL and MySQL

#27

Post by amirmc »

If anyone's interested in git-like storage systems then it's work checking out Irmin [1]. Previous discussion is at [2].

Excerpt: "Irmin is a library to persist and synchronize distributed data structures both on-disk and in-memory. It enables a style of programming very similar to the Git workflow, where distributed nodes fork, fetch, merge and push data between each other. The general idea is that you want every active node to get a local (partial) copy of a global database and always be very explicit about how and when data is shared and migrated

Irmin is not, strictly speaking, a full database engine. It is, as are all other components of Mirage OS, a collection of libraries designed to solve different flavours of the challenges raised by the CAP theorem. Each application can select the right combination of libraries to solve its particular distributed problem."

[1] http://openmirage.org/blog/introducing-irmin

[2] https://news.ycombinator.com/item?id=8053687

Re: Show HN: Stellar – Git for PostreSQL and MySQL

#29

Post by jdc0589 »

Shameless plug for mite: https://github.com/jdc0589/mite-node Simple migrations that take advantage of everything you already know about git and sql, plus some other cool stuff.

It's not too mature yet, the readme is mediocre at best, and it has some issues that will popup when working with a team, but it's pretty damn useful.

Re: Show HN: Stellar – Git for PostreSQL and MySQL

#30

Post by jimktrains2 »

While not exactly the same thing, I've recently found and started using https://github.com/nkiraly/DBSteward to specify schema and then store the spec in my repo with the code. It also supports diffing the current schema against a previous one, so that nice upgrade sql scripts can be generated.
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