Re: O_DSYNC broken on MacOS X?

Greg Smith wrote:
> A.M. wrote:
> > Perhaps a simpler tool could run a basic fsyncs-per-second test and prompt the DBA to check that the numbers are
withinthe realm of possibility.
 
> >   
> 
> This is what the test_fsync utility that already ships with the database 
> should be useful for.  The way Bruce changed it to report numbers in 
> commits/second for 9.0 makes it a lot easier to use for this purpose 
> than it used to be.  I think there's still some additional improvements 
> that could be made there, but it's a tricky test to run accurately.  The 

test_fsync was designed to test various things like whether several
open-sync writes are better than two write and an fsync, and whether you
can fsync data written on a different file descriptor.  It is really a
catch-all test right now, not one specific for choosing sync methods.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + It's impossible for everything to be true. +