How does kdb compare to cloud computing?

Cloud-based solutions (such as Hadoop) are great if

• you have developers who know how to program them
• you don’t mind putting your data on a cloud
• the data you need for even a single query can’t fit in memory
• you can afford to wait minutes for your query results

For some applications, then, clouds are an excellent approach. kdb+, however, is typically used in scenarios where

• you can’t (e.g., due to licensing) or don’t want your data outside your firm
• you don’t have an in-house cloud infrastructure
• you don’t want each query to be an IT project in and of itself
• you want the answer to your query in milliseconds (or seconds at worst)
• you can fit your data in memory (not necessarily all at once)