when to use what you can apply internal algorithms to the entire file just as if it was all in memory at the same timeand let the operating system worry about reading the appropriate part of the file if it isn' in memory already of courseoperation will be much slower than when the entire file is in memorybut this would also be true if you dealt with the file block by block using one of the external-storage algorithms it may be worth simply ignoring the fact that file doesn' fit in memory and seeing how well your algorithms work with the help of virtual memory especially for files that aren' much larger than the available memorythis may be an easy solution onward we've come to the end of our survey of data structures and algorithms the subject is large and complexso no one book can make you an expertbut we hope this book has made it easy for you to learn about the fundamentals appendix "further reading,contains suggestions for further study