Can we use Java jobrunr without database. Basically I want to use only the background run feature less priority tasks and any issues with running those would be ignored.
In your case you can try the InMemoryStorageProvider, which is ideal for testing and for lightweight tasks that are server-instance specific and where persistence is not important. Note that if you use the InMemoryStorageProvider, you can not scale horizontally as the storage is not shared.
Based on: https://www.jobrunr.io/en/documentation/installation/storage/