Make sure that stakeholders understand compounding index issues with larger data set

[kltm]

From #388 , we note that:

• generated compressed index is 25G, instead of 8.8G
• expanded, we also see 3x: 312G vs 101G
• generation time is 7.2h vs 5h (so scales nicely there)

Any expansion to our Solr indexing, like more fields or stemming, could quickly compound some of the above.
As well, larger indexes will affect things like stats generation.