# PgPartitioner

It's a gem for a partitioning Postgresql tables in Ruby on Rails.
Now gem can help you with partitioning tables by months. New table for each month.

## Installation

Add this line to your application's Gemfile:

```ruby
gem 'pg_partitioner'
```

## Usage

1) Include PartitionerPg into your model: `include PartitionerPg`. Also, you can specify parting column and some indexes.
Example:
```ruby
class YourModelName < ActiveRecord::Base
  extend PartitionerPg::SeparationType::Month

  # Point date or datetime column which will be used for monthly partitioning. Optional (:created_at uses by default)
  def self.parting_column
    :date
  end

  # List of indexes. Names of indexes will be generated by active migration. Optional.
  def self.partition_table_indexes
    [
      %w[column1 column2]
    ]
  end

  # Map of indexes. Full name of named index will be generated as "index_[partition_name]_[name_of_index_from_map]". Optional.
  def self.partition_table_named_indexes
    {
      :three_cols => %w[column1 column2 column3]
    }  
  end

  # List of unique indexes. Names of indexes wiil be generated by active migration. Optional.
  def self.partition_table_unique_indexes
    [
      %w[column1 column2 column3 column4]
    ]
  end

  # Map of named unique indexes. Optional.
  def self.partition_table_named_unique_indexes
    {
      :uniq => %w[column5 column6 column7]
    }
  end
end
```
2) Create migration and add some instructions to it. Generate migration:

```
rails g migration make_partitioning_of_you_table
```

add instructions to migration:

```ruby
class YouMigrationClassName
  def change
    YourModel.create_partitioning_by_week_trigger_sql
    YourModel.create_current_week_table
    YourModel.create_next_week_table
  end
end
```

```ruby
class YouMigrationClassName
  def change
    YourModel.create_partitioning_by_month_trigger_sql
    YourModel.create_current_month_table
    YourModel.create_next_month_table
  end
end
```

```ruby
class YouMigrationClassName
  def change
    YourModel.create_partitioning_by_quater_trigger_sql
    YourModel.create_current_quater_table
    YourModel.create_next_quater_table
  end
end
```

3) For correct work you need to create next partition every month/quater.
  We recommend you to create a rake task and run it once a month by crontab. Code for a rake task:

```ruby
YourModel.create_next_week_table
```
  or
```ruby
YourModel.create_next_month_table
```
or
```ruby
YourModel.create_next_quater_table
```