PgClosureTreeRebuild

Quick #rebuild! method implementation for closure_tree on PostgreSQL.

Say you have a table with 1M+ hierarchical records and you want to migrate it to closure_tree. Initial rebuild of hierarchies table using the standard #rebuild! method will take a dramatically long time. This library speeds up the process. It makes all the calculations using pure in-memory array and writes the result using COPY FROM STDIN BINARY.

Installation

Add this line to your application's Gemfile:

gem 'pg_closure_tree_rebuild'

And then execute:

$ bundle

Or install it yourself as:

$ gem install pg_closure_tree_rebuild

Usage

$ bundle exec rake closure_tree:rebuild DATABASE_URL=postgres://localhost/tags TABLE=tags HIERARCHIES=tag_hierarchies PARENT_ID=parent_id ID=id

You can bypass all params except database URL and table name.

Rebuilding hierarchy for 1162537 records with 4 generations in average takes 2 minutes 58 seconds on my MacBook Pro i7 2.3GHz, while the rebuilding with the standard method takes hours.

Contributing

1. Fork it ( https://github.com/gzigzigzeo/pg_closure_tree_rebuild/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request