Re: EXPLAIN ANALYZE printing logical and hardware I/O per-node

On Dec 18, 2007, at 3:32 AM, Gregory Stark wrote:
>> Also, has anyone looked into adding a class of system calls that   
>> would
>> actually tell us if the kernel issued physical IO? I find it  hard  
>> to believe
>> that other RDBMSes wouldn't like to have that info...
>
> Yeah, I think that's called "DTrace"


That seems like way overkill...

When a read() call returns, surely the kernel knows whether it  
actually issued a physical read request to satisfy that. I don't see  
any reason why you couldn't have a version of read() that returns  
that information. I also rather doubt that we're the only userland  
software that would make use of that.
-- 
Decibel!, aka Jim C. Nasby, Database Architect  decibel@decibel.org
Give your computer some brain candy! www.distributed.net Team #1828