Extract: Push, Pull or Publish/Subscribe

There are different extraction models. They are pushing, pulling and publish/subscribe models.

Push

• Extraction program is running in the upstream system.
• Can be generic format for multiple receivers or specific format for particular receiver
• Separated process may be required to transfer the extracted files

Pull

• Extraction program is running remotely in the destination system
• Specific format for destination

Publish/Subscribe

• Usually a corporate middleware for standard data transferring across systems
• Extraction program is running in the publisher system.
• Publisher publish the extracted data to some middleware
• Data are then pushed to or downloaded by the subscribers. (potentially multiple subscribers for single interface)
• Usually extracted as the corporate's standard/format if available. Or simply use publisher system format