I am new here, now one month into the oracle-world. I managed to get an oracle cloud instance setup from my company as well as setting up my own private one. On both I installed Oracle 19c with the hr-schema, which took a while, but I'm getting around.
I also successfully connected SQL Developer (via Oracle Connections and via a SSH Host) to the databases twice (once from my work-computer, once from my private one). As a preparation for an Oracle Certification I am trying some queries on the database, unfortunately after a few successful queries the connection keeps shutting down at random times when a query is executed, with one of the following error messages:
I then try to reconnect by right-clicking the Oracle Connection and selecting "Reconnect", which works most of the time:
Sometimes the connection is refused, giving me the well-known error message with Vendor code 17002:
Sometimes when executing a query the connection gets an automatic reconnect and then the server refused message appears, as seen here:
The connection keeps shutting down after a random period of time and a random amount of successful queries. Sometimes the connection was still working after lunch break, sometimes it keeps shutting down immediately.
This happened on every possible setup I have (company Laptop - company cloud, company Laptop - private cloud, private Laptop - company cloud and private Laptop - private cloud).
I tried it with two different internet connections and with the Windows Firewall shut down.
My Laptops are both Win10 with the latest Version 220.127.116.114 and
the cloud instances are both Oracle-Linux-7.7-2020.02.21-0 machines with (as said before) Oracle 19c installations.
I am connecting with the "hr" user which I specified when I manually ran the script for the creation of the hr database, but I had the same problems with the SYS users for the container and the pluggable database.
In both instances I have installed the Oracle Installation without a database, because I applied the newest patch (p30463595) after the installation first and then ran the dbca creating the container (orcl) and one pluggable database (pdb1 with hr-schema)
If necessary I can provide any information, maybe I need to ask how to get the information though.
Maybe somebody can help me or point me to what I am doing wrong. I do think it might be some load-timer or something, but since the queries before the connection shutdown are working I am now out of ideas. I believe the database and the listeners are set up correctly since the connection does work before the connection shutdown from the server.
Thank you very much, best regards,