> ## Documentation Index
> Fetch the complete documentation index at: https://private-7c7dfe99-vortex-format.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

> Frequently asked questions about ClickPipes for BigQuery.

# ClickPipes for BigQuery FAQ

<h3 id="time-travel-window-exceeded">
  My ClickPipe fails with "change history start time is before allowed time travel interval"
</h3>

[`APPENDS`](https://docs.cloud.google.com/bigquery/docs/reference/standard-sql/time-series-functions#appends) and [`CHANGES`](https://docs.cloud.google.com/bigquery/docs/reference/standard-sql/time-series-functions#changes) can only read changes within the source table's [time travel window](https://docs.cloud.google.com/bigquery/docs/time-travel), seven days by default. If the ClickPipe falls behind by more than that window, BigQuery no longer has the changes it needs. Resync the ClickPipe to unblock it.