[stevenp]

My experience working with Solr is that a lot of the time people don't have a good working knowledge of how to optimize an index because it's so easy not to. At my last job, the initial implementation they we involved storing the full text of millions of documents, even though they never needed to be retrieved (just searched). If you're running Solr as a front-end search for another database, the best way I've seen to optimize performance is just to make sure you're not storing data unnecessarily.

Maybe everyone already should already know this, but I was working on a very smart team, and we totally missed this initially. Setting "stored" to false for most fields resulted in a 90% reduction of the index size, which means less to fit into RAM.

[raccoonone]

Yep, totally agree with this. Last month we spent an hour or two going through the schema and removing any fields that didn't need to be stored, and making sure that only fields which we actually do queries on had index=true. I didn't test before and after results, but qualitatively it seemed to be faster afterwards.