Optimizing code and algorithm to sort very large file

The file that this program will sort is titled randomkeys, It is very important to note that is a 2.3GB file and is a randomly generated file. You can assume the format of this file and that of the numbers (number of floating point digits after the decimal point, etc.) This program needs to be able to sort 10^9 keys and this value should be hardocded into the code. You can use any sorting algorithm in C. The code should time the execution, including I/O, and print the execution time to stdout upon completion of the execution. This code must run on a specific server and this information will be provided. This is a 32 bit machine and this program must be a single executable and not use shell scripts or call shell commands. This must also run on a single processor. The goal is to make this program run as fast as possible. Ideally, less than 20 minutes. One hint is that I found that fopen64 seems to deal better with the file size but any ideas on minimizing the IO are ideal. Only bid on this if you are very familiar with optimizing and dealing with the constraints on very large files that do not fit into memory directly. The code should be commented very well. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows? (depending on the nature? of the deliverables): a)? For web sites or? other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software? installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform Unix