The default is 30 seconds 30s. For WAL a transaction has to do two things to modify a row. This comes from simple fact — generally, over time, more and more different pages get dirty.
The default is 1 GB. To record new write PostgreSQL would have to either do checkpoint which it will dobut at the same time — it wouldn't have any more ready segments left to use.
For example, in Fig. The upper limit is a soft limit, because the server can safely delete only those files which have been successfully archived. Not all are even guaranteed to be used they could contain data that got removed.
On the other hand — please note that we have ready seven files for future use. The modified page is not written into the storage yet.
Kill it. You should treat the file that PostgreSQL passes you as read-only.