# FLOW Schedule

There are three types of Input available in FLOW.

* **Pull**
  * e.g. Salesforce, Oracle, MySQL etc. which runs at a regular interval and polls for any changes in the source system.
* **Push**
  * Webhook to which the events get pushed by the source system
* **CDC**
  * e.g. Oracle CDC, MySQL CDC which listens for changes in real-time

All the pull inputs will be scheduled based on the Schedule Policy chosen at the time of flow creation.

![](https://272493989-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LyGZIunpED9t56ZtLzh%2F-Ly_PB_5ZOacfPomIarM%2F-Ly_Ze4wGoNS9qe7hBtB%2FScreen%20Shot%202020-01-14%20at%2011.39.03%20AM.png?alt=media\&token=3b85e7b3-b820-4ba2-a2cf-ec9044579dcd)

1. [**Cron Expression**](https://flow-docs.cloudio.io/getting-started-with-flow/flow-schedule/cron-schedule) - use this to schedule at a specific time of the day or day of the week/month etc using a cron expression
2. **Fixed Interval** - use this to schedule every x minutes
3. **After Parent Flow** - use this to define dependency between flows. You can choose to run this flow soon after the parent flow runs irrespective of the status.
4. **After Parent Flow Success** - similar to the above, but only runs if the parent flow completed without any errors.
5. **After Parent Flow Failure** - similar to the above, but only runs when the parent flow completed with errors.