[nikisweeting]

Happened all the time to me before I did some tuning Depends how much write contention you have and how long open transactions take to finish.

[rbranson]

The list of circumstances for WAL-mode busy errors is in the doc linked by one of the posters above. It has nothing to do with transactions.

[ncruces]

That list lists reasons queries might return busy; queries aka. reads.

Reads returning busy is rare under WAL, but WAL mode does very little for writer-writer contention.