How to load .dat files to oracle database I have .DAT files extracted from telecom switch. 

I want to upload this file to an Oracle server using IBM data-stage ETL tool. 

Unfortunately these files are not readable format.

This is a picture of the .DAT file when opened in notepad:
Not all .dat files are the same and it's hard to determine from the screenshot what the format is.

If you extracted that from a telecom switch, you will need to contact the telecom vendor to ask if they have a data provider for the file format and use that provider to make a connection to the .dat file from within your ETL tools.

If they don't have a provider, which is entirely plausible, you will need to extract the data in another format such as .csv. Again, contact the vendor to see if that is an option