A Simple REPL tool to migrate from MySQL to PostgreSQL. (Beta)
Migrating from MySQL to PostgreSQL is not completely straightforward. Based on my experience, I'm not certain if it's possible to have one tool that's preconfigured to reliably migrate 100% of time without any tweaking.
This tool is meant to address some of this. It's simply a small framework to get you running a lot faster in your migration. Good luck!
This tool has been created and tested on OSX, however it's very likely it will work fine on Linux for performing work directly on your server(s). I'm not a Haskell expert so that's the part that you'll have to venture on your own.
- OSX
- Homebrew
- Haskell (runghc, cabal). See install script for more info.
- Ruby 1.9
- Bundler
- mysql client
- psql client
- network connectivity to both MySQL and PostgreSQL servers
-
Copy config.yml.example to config.yml adjust to your environment and needs.
-
Copy lib/my_migrate/custom_actions.rb to lib/my_migrate/custom_actions.rb and tweak, see below.
There are default actions that occur in a typical migration from MySQL
to PostgreSQL. Dump DDL, Dump data, transform DDL,etc. All of these are
reflected in the "Actions" class in lib/my_migrate/actions.rb. This is
effectively where all the work is done. They are simply methods that
return a string that will be executed as is in shell.
You can review these actions here and make adjustments if you need to, but CustomActions are for that. Read on.
Custom actions allow you ability to add your own commands that you need
to perform in the workflow of your migration. They are simply methods
like in Actions class, that are referenced in actions_set in the
config.yml. You place your own custom actions methods in the config,
restart the console and you are good to go.
Haskell for using DDL converter ( https://github.com/danchoi/mysql-ddl-parser).
brew install parallel
brew install ghc --64bit --use-llvm
brew install haskell-platform --64bit --use-llvm
cd my_migrate
sh install
Then bundle
bundle
bundle exec bin/console
You should see the Pry prompt.
[1] pry(main)>
MyMigrate is a simple object with a few accessors and methods on those. It's really a couple of accessors and those are filled with Mashes from Hashie Gem.
To list the actions:
[1] pry(main)> MyMigrate.actions.list
=> ["dump_mysql_ddl",
"fix_timestamps_in_mysql_ddl",
"convert_mysql_ddl_to_postgres",
"split_indexes_from_postgres",
"split_ddl_from_postgres",
"dump_mysql",
"fix_nulls",
"drop_create_target", "load_postgres_ddl",
"load_csvs",
"load_postgres_indexes"]
To see the config:
MyMigrate.config
MyMigrate.actions.run_all
Change dry_run to true in config.yml and restart or set via
MyMigrate.config like so:
MyMigrate.config.dry_run = true
MyMigrate.actions.run_all
MyMigrate.actions.run_and_skip ['load_csvs']
MyMigrate.actions.run_until ['update_synchronized_time']
MyMigrate.actions.run 'load_csvs'
- Fork the project.
- Make your feature addition or bug fix.
- Add tests for it, tests are a WIP, this tool is a very specific use case.
- Send me a pull request. Bonus points for topic branches.
Thanks to @danchoi for creating Haskell parse program to do DDL transformation at https://github.com/danchoi/mysql-ddl-parser
Copyright (c) 2013 Hank Beaver and Obie Fernandez