Please open a support case and provide the following information. 

1. Laserfiche server version and build number.

2. Oracle server version and release number and Oracle client version installed on the same machine as Laserfiche Server

3. Provide a copy of the application and system event logs from the Laserfiche Server machine in evtx format and unfiltered.

4. From your posted notes "oracle database server continues to crash and reboot by itself" , Do you mean the machine that host the oracle server instance crashes then reboot? or do you mean the machine that host the laserfiche server instance crashes and then reboot? Laserfiche server works with an schema that is created in a Tablespace within the oracle database, it is unlikely to bring down the entire oracle server. Also oracle database does not only work with Users Tablespace (default Tablespace where schemas a created unless this oracle system has being customize) . It does interact with Temp Tablespace as well. if this last one is not able to extend running out of space then that might be causing the issue.

Please make sure the Customer Oracle DBA check the oracle logs files for further details. The information I listed above lines is required to expedite the resolution of the issue when you submit a case.