Streaming insert limit

[zero-master]

Streaming insert limits are documented here:
https://cloud.google.com/bigquery/quotas#streaming_inserts

This project uses fixed windows of a minute:

pubsub-backup/src/main/java/backup/BackupPipeline.java

Line 59 in 7dd0f12

Window.<TableRow>into(FixedWindows.of(Duration.standardMinutes(1))))

If you end up going over the limit for streaming inserts, this might cause some issues with your pipeline.

What do you think about using something like this?

Composite trigger that fires whenever the pane has at least 100 elements, or after a minute.

Repeatedly.forever(AfterFirst.of(
      AfterPane.elementCountAtLeast(100),
      AfterProcessingTime.pastFirstElementInPane().plusDelayOf(Duration.standardMinutes(1))))

where the number 100 can be configured/calculated based on the size of the row to not go over the streaming insert limits.