Quote from: sturle on July 08, 2015, 05:40:03 PM

Quote from: tuvok007 on July 08, 2015, 05:25:02 PM

Quote from: favdesu on July 08, 2015, 04:56:09 PM

your tx fee is very very low... this could take some time. even without an attack

I know and i regret now. Is it possible to undo things? to send somehow a bigger fee for that transaction? sorry if it is a stupid question but I am desperate.

Yes. Two ways:
1. You can either create a new transaction using the same inputs and a higher fee, hoping for this double spend to confirm.
2. Spend the change output with a high fee, and hope for a pool practicing child-pays-for-parent to pick up both and confirm them. Eligius, EclipseMC and possibly others do this.

Method 2 has a higher probability of success, as the double spend will have problems getting relayed to the miners.

Never knew that this is possible until I read it today. However I have a question, what if I have created two transactions, one with fees and one without fees? I send 1 btc to the same address two times but with only different fees. Is it possible that the two tx be confirmed at the same time if I only have 1btc?