This post suggests that Stack Overflow has about 30,000 distinct tags, which seems like a good fit for a bitmap index:<p><a href="https:&#x2F;&#x2F;mattwarren.org&#x2F;2015&#x2F;08&#x2F;19&#x2F;the-stack-overflow-tag-engine-part-2&#x2F;" rel="nofollow">https:&#x2F;&#x2F;mattwarren.org&#x2F;2015&#x2F;08&#x2F;19&#x2F;the-stack-overflow-tag-eng...</a><p>Not that that&#x27;s the whole solution, but certainly something I&#x27;d look into before digging into CUDA.