Please read about I/O, memory and cache hierarchy. If you access a hot row, 10,000 times in a minute, that would be 10k fopens() / fcntl() / fclose() calls. Ben

Please read about I/O, memory and cache hierarchy. If you access a hot row, 10,000 times in a minute, that would be 10k fopens() / fcntl() / fclose() calls. Benchmark that in a C program and also benchmark pre-allocated memory page access with a cache in a loop 10k times. That is just reads. If you include writes + transaction logs + join queries etc., individual files become unwieldy very soon.