unable to get transactions in wallet console I'm trying to get transactions infos out of the bitcoin core wallet with the console.
For that I picked a random transaction of a block from today and tried to access it with


  gettransaction 8c0430d0139603db9983daf539604c612b3f7e8d5244aefc3cd3181ece08dd1f


Instead of a json-output with the decoded transaction I get 


  Invalid or non-wallet transaction id (code -5)


Shouldn't I be able to retrieve every transaction in the blockchain with this command?

How can I read/access the transactions included in mined blocks? 
I already did this on some altcoins with PoS and there is was possible for every transaction. Now with bitcoin it seems that only wallet transactions are available? Why is that and can I get around that to access / read the transactions on my own?

The same problem appears to be with the getrawtransaction command, so I can even decode a transaction on my own.

I run a bitcoin core 0.14.2 and my blockchain is up-to-date.
To retrieve arbitrary transactions in the Bitcoin Core console, you need to use the txindex=1 option in your configuration file.

Note that setting that option will trigger a full rescan of the blockchain that might (depending on your setup) take several hours to complete.