Daniel Migowski wrote:
> getString on text_col took 8.27384ms
> getCharacterStream on text_col took 14.26489ms
> Factor: 1.724095462324628
> getString on varchar_col took 9.57153ms
> getCharacterStream on varchar_col took 12.76733ms
> Factor: 1.3338860140437319
> Conclusion: There is no real performance loss even in the worst case
> (which should never occur anyway), so please accept my patch. I wish you
> all a happy new year!
I'm confused. Don't your numbers show a 30%-70% slowdown when using
getCharacterStream()?
Also some quick notes about microbenchmarks:
- 1000 iterations isn't really enough to get useful numbers, try 20,000+
for JIT effects or considerably more for GC effects
- server vs. client JVM can have quite different behaviours, you should
check both
- put your inner benchmark loops in a separate method as some JIT has
method-level granularity
- benchmark the same code path in your warmup loop as you actually
measure the numbers from. In your code, you're benchmarking a different
code path to the one you run in your warmup loop.
-O
