[lqdc13]

Not sure about 2GB limit though. It doesn't work well at low RAM. Probably better to just use your own suffix tree or some trie for all the stuff you want to search for and use that. I bet you can get it down to something like 100MB.

[loopbit]

Depending on the index size (and type of queries, and schema, and expected performance...), 2GB might be more than enough. Solr does a very good work in caching results, query filters and so on in memory. Apart from that, it's disk based.

Of course, performance won't be stellar if it has to go to disk to find every result, but even with that you should be able to get sub-second results with some tweaking.