CORE-1207. Improving Liquibase startup time by pre-caching values of cos...

[kyrill007]

...tly methods in SqlGeneratorFactory: 50% improvement in startup speed.

[amuraco]

I've adopted this in a local build of liquibase and haven't seen any significant down sides to it. Technically, these classes can't get unloaded by the classloader, but I don't think they were likely candidates anyways.

[kyrill007]

I didn't imply class unloading. I am just trying to prevent those expensive calls. Do you think you may merge this pull request relatively soon?

[pieterbos]

I've seen the problem as well. We have a large changeset to test this with that takes 20 seconds to run even with no changes (we should clean it up).

This call is used to check if a change supports a database.

I solved it differently locally: by not running all the validation checks if the change has already been ran and it should not be run this time either. I'll check if i can add a pull request for that feature too, but i'm not sure if it has dangerous other effects. It's a 50% speedup in my case.

Another fix is caching the result in AbstractChange in a similar way as this pull request, since it gets called several times with the same parameters from there!

[nvoxland]

Thanks, the change does look good. There is definitely other reflection based caching we can do as well. I'll keep an eye out for it.

@pieterbos, if you can add a pull request for your change that would be great too.