> ## Documentation Index
> Fetch the complete documentation index at: https://artie.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.
# Backfills
> Artie runs CDC and backfills in parallel without data conflicts or database load. Database changes are enqueued in Kafka as the backfill is running and applied after backfill completes.
## How it works
This is how Artie handles backfills for each table:
* Scans full table in batches, writes directly to destination
* Can use read replica to minimize primary DB load
* Reads database logs immediately
* Queues all changes (inserts, updates, deletes) in Kafka
* Artie applies the queued CDC changes in order
## How to kick off a backfill
By default, when you onboard a new table, Artie will kick off a backfill to copy all the historical data to your destination.
This is how you trigger an adhoc backfill:
1. Click on any running pipeline and go to the pipeline overview page
2. Click on the Backfill tables button
Subsequently, canceling a backfill can be done from the Pipeline overview page.
## Advanced settings
You can configure the additional backfill options from the advanced settings on the source tab in the pipeline editor.
## How are backfills ordered?
In FIFO order, tables are backfilled in the order they were added, up to the concurrency limit.
## What happens to CDC changes during a backfill?
Our process continues to capture all changes to Kafka in the background. Once backfill completes:
1. We switch to CDC stream
2. We apply queued changes in order
3. The table transitions to fully streaming state
This guarantees consistency and prevents stale data overwrites.