Once arrested you will have an arrest record for life! ANYBODY WHO DOES A BACKGROUND CHECK ON YOU WILL SEE YOUR ARREST, CONVICTED OR NOT! What happens AFTER the arrest is called the disposition. You will also have that for life, in your FBI file. The disposition of any case is what most employers are looking at, as long as your rap sheet isn't very long or serious. Maybe it says probation, or dismissed. If it is open you can expect an employer to not consider you for hire. You can't blame them. They are not going to spend money on training you just to see you go off to jail. There is also the issue of trust and integrity. If you were going to work at a bank or run a cash register you can bet an employer will look closely at any arrests, convictions and dispositions. But sometimes a disposition won't show up, so it looks like you are still in the court system.
For example say you got arrested for public intoxication 14 years ago. The officer just wanted you to sleep it off and had no intention of charging you. You would have an arrest record, but because the charges were dropped the disposition SHOULD show as DISMISSED. However, the local court system has to enter that information into NCIC or it will show as an OPEN charge. And believe me, local governments have better things to do than to worry about doing you a favor by fixing the disposition of a case. You need to get a copy of your FBI file to see the disposition of any case ever brought against you so you can take steps to get accurate information in your file.
Also consider that any convictions will show up in the same place...... FOR LIFE! Many employers say they only go back 10 years, but a background check will reveal EVERYTHING you were ever charged with and it's disposition. Good luck!