Question

In my website’s advanced search screen there are about 15 fields that need an autocomplete field.
Their content is all depending on each other’s value (so if one is filled in, the other’s content will change depending on the first’s value).
Most of the fields have a huge amount of possibilities (1000’s of entries at least).

Currently make an ajax call if the user stops typing for half a second. This ajax call makes a quick call to my Lucene index and returns a bunch of JSon objects. The method itself is really fast, but it’s the connection and transferring of data that is too slow.

If I look at other sites (say facebook), their autocomplete is instant. I figure they put the possible values in their HTML, so they don’t have to do a round trip. But I fear with the amounts of data I’m handling, this is not an option.

Any ideas?

Answer 1

1. Return only top x results.
2. Get some trends about what users are picking, and order based on that, preferably automatically.
3. Cache results for every URL & keystroke combination, so that you don’t have to round-trip if you’ve already fetched the result before.
4. Share this cache with all autocompletes that use the same URL & keystroke combination.
5. Of course, enable gzip compression for the JSON, and ensure you’re setting your cache headers to cache for some time. The time depends on your rate of change of autocomplete response.
6. Optimize the JSON to send down the bare minimum. Don’t send down anything you don’t need.