[manigandham]

This isn't about raw physics and biology but rather the use of business applications by users, specifically with regards to analytics and exploratory queries.

Anything less than a second to run a query and return results is considered "instant" (also sometimes "interactive") for analysis.

[thinkMOAR]

Since the example data is stock data, i think it is safe to assume people don't want to be 249.9ms late with their purchase :)

[manigandham]

What? No human trades that quickly, and this is not about automated HFT trading systems but rather running database queries and what typical business users expect as "instant" results.