Background:
My CSS360 group is attempting to create an Android application that will include an auto-complete search feature. The data that we'll be searching consists of around 7000 entries, and will be stored in a SQLite database on the phone itself. The most obvious approach would be to do a linear search of the database following every character that the user types, and then return a list of suggestions which are potential alphabetic extensions of the user's query. However, this seems like it would be pretty inefficient, and we've been looking for better alternatives. In another one of my classes today, my instructor briefly discussed the trie data structure, and mentioned that it's often used to store entire dictionaries. Entries into a trie can be retrieved in logarithmic time (as opposed to linear time for a regular old array), so this seems like a great tool for us to use! Unfortunately, we're in waaaay over our heads on this project already, and none of us really have a clue how to make this happen. All any of us have ever coded to date are basic console applications to teach us programming basics. We're all attempting to learn the Android platform in a week's time by watching YouTube videos, and differing the database stuff to the one guy in our group who has any SQL experience whatsoever. We could seriously use some pointers!
Questions:
- When creating a trie, is it possible to have the entire structure pre-populated? IE: generate a line of code for every node used, so that the entire structure will already be in memory when the program starts? My thinking here is that this will save us the overhead of having to regenerate the entire trie from the database every time the program starts. If so, is there an easy way to get these thousands of lines of code into our program? IE: Some sort of script which converts the database files into a giant text file of java commands which can be copied and pasted into Eclipse?
- Will there be a considerable amount of overhead if we search the database directly instead of using some sort of internal list or data structure? Should we be copying the names out of the database and searching them inside the program for our auto-complete function?
- If this proves too technically difficult for us, and we have to resort to a regular linear search, will the performance be noticeably affected?
- Our current plans are to run the auto-complete function each time the user enters a character, and then wait for the function to return before allowing them to continue typing. The only programs any of us have written so far function synchronously like this. What would we need to know to make this function asynchronously? Considering our novice abilities, and the requirements that we're already having to meet, would this be too technically challenging for us?
