solutus/play_db

database, implemented from scratch for study purpose

Database implementation on ruby.

Description

define_my_db(:my_database) do |db|
  db.create_table(:order) |table|
    table.autoincrement_primary_key 
    table.integer :department_id
    table.string :description, size: 10
    table.datetime :created_at 
     
    table.index :description
  end

  db.create_table(:comment) |table|
    table.autoincrement_primary_key
    table.integer :order_id
    table.string  :description, size: 10
    table.index :order_id, :hash 
  end
end

Order.find_by_id(3)                    # must be O(log(N))
Order.find_by(description: "anything") # must be O(log(N))
Comment.find_by(order_id: 4)           # must be O(1)

Testing

ruby ruby_db.rb

Results

Restrictions: Indices are being updated in RAM. To save it to filesystem flush_indices method must be used.