super simple migrator for AWS Redshift (and PostgreSQL)
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README.md

RedshiftSimpleMigrator

Build Status

this gem is super simple migrator for AWS Redshift (and PostgreSQL).

Installation

Add this line to your application's Gemfile:

gem 'redshift_simple_migrator'

And then execute:

$ bundle

Or install it yourself as:

$ gem install redshift_simple_migrator

Usage

Define migration

Migration definition is like ActiveRecord::Migration, but this gem supports only execute method. It has no other migration dsl.

Migration File

class CreateKpiMiddleTable < RedshiftSimpleMigrator::Migration
  def up
    execute <<-SQL
      CREATE TABLE company_users DISTKEY (id) AS
      SELECT
        a.id,
        a.company_id
      FROM
        users a
          INNER JOIN companies b ON a.company_id = b.id;
    SQL
  end

  def down
    execute <<-SQL
      DROP TABLE company_users;
    SQL
  end
end

File name convention

File name convention is same with ActiveRecord::Migration.

% ls redshift/migrate/
001_create_kpi_middle_table.rb

Command

# Show current migration version
$ redshift_simple_migrator version -c <config.yml>

# List execute migrations
$ redshift_simple_migrator list <TARGET_VERSION> -c <config.yml> -p <migrations_path>

# Execute migration
$ redshift_simple_migrator migrate <TARGET_VERSION> -c <config.yml> -p <migrations_path>

If you use with rails, config is autoloaded from config/redshift_simple_migrator.yml, and define Rake tasks.

Rake tasks

rake redshift:migrate                   # Migrate the AWS Redshift (options: VERSION=x)
rake redshift:migrate:status            # Display status of AWS Redshift migration (options: VERSION=x)

config.yml example

default: &default
  host: hogehoge.redshift.amazonaws.com
  port: 5439
  dbname: sample
  user: admin
  password: password
  connect_timeout: 30000
  schema_migrations_table_name: redshift_schema_migrations

development:
  <<: *default

If schema_migrations_table_name table doesn't exist, this gem creates the table automatically.

schema_migrations table schema is following.

CREATE TABLE <schema_migrations_table_name> (version text NOT NULL)

TODO

  • Refine migrations_path config.
  • Write test codes.

If you want to change target environment, set REDSHIFT_ENV environment variable. For example, REDSHIFT_ENV=prouduction redshift_simple_migrator migrate -c config.yml -p db/migrate

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake false to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment. Run bundle exec redshift_simple_migrator to use the gem in this directory, ignoring other installed copies of this gem.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/joker1007/redshift_simple_migrator.