Searching in a long text

Hi all, I'm implementing a search tool to find phrases inside a book. Users will search for some word, then the engine will returns the 3 or 4 lines containing that word, and giving also the book page number. I have the book in plain text and the doubt is about different approaches in order to be speedy and saving memory and resources: - adding every text page inside fields of one MySQL table. - having the whole book as a unique text file, with some marks in every page to delimit and parse the page number Also, I want to know if there is some possibility to make the same using PDF files. thanks in advance