schema.rb vs. migrations

[ashes999]

Hi,

The docs mention that you can specify migrate: true to use migrations instead of the pre-generated schema.rb.

I'm a bit new to Rails (again). What's the trade-off here? How would I know which one to choose?

[haslinger]

It's possibly slower to run, especially when you have lots of migrations, compared to one schema loading. If your migrations are broken, you obviously can't use them (which is the case, if you didn't keep them consistent).

[mknapik]

To solve the this run MemoryTestFix::SchemaLoader.init_schema after Spring fork.

Create config/initializers/spring.rb if does not exist:

Spring.after_fork do
  MemoryTestFix::SchemaLoader.init_schema
end

[mvz]

@mknapik I think you meant to comment on #3? In any case, thanks for the tip, I'll see if I can incorporate that in memory_test_fix so people don't have to add an initializer.

[mknapik]

@mvz Yes, not sure why it ended up here :-)

[mvz]

@ashes999 some reasons for using migrate: true could be to help make sure your migrations don't break due to changes in the code elsewhere (whether this is useful depends on your use-case), or to make some seeding data be available. If those reasons don't apply, keeping it at the default is probably faster.

TL;DR: Use the default unless there's a clear reason not to. You can always switch later.

[mvz]

I moved this Q&A to the Wiki.