Hello i have got Data base log with me extracted as txt file can i onboard this to splunk and query it to form dashboards withou any splunk apps like DB connect and once i am good with this can we have forwarder installed on DB machine and pull these logs to splunk
Yes, absolutely. The DBConnect app is for collecting data from inside a relational database, not for collecting the database logs.
For any log file (or other text file), you can use the Splunk input settings to read the file; you don't need an app for that. If you want to test a particular log file, you can copy it to your Splunk server and index it as a local file. Once you are good with that, you can use a forwarder with the same inputs.conf to collect the live logs and send them to your Splunk server. Again, no apps are required.
However, sometimes you will find that there is an app on Splunkbase (www.splunkbase.com) that will do exactly what you want: collect the log files, parse them and provide some interesting reports. So it's always worth checking but it is never required.