Hi ,
I've received a two interesting questions from a collage of mine.
1)
If two processes are writing to the same file , will they suffer from some
conation on the file handler ?
Do you think that spreading very busy tables (has a lot of inserts from
different sessions) on different tablespaces (which will be translate to
different data files ) will have better I/O performance over one single data
file ?
I'm talking only from performance perspective , not from backup & recovery
?
££There is the so-called single file write lock in unix.
Raw volume/disk does not have this problem.
and solaris/AIX 5.3 now have feature called Concurrent IO, which also solves
this problem.
I am not sure, when we have several dbwr configured, whether different dbwr
will write to the same datafile in the same time.
2)
If we have tablespaces with several data files . Will oracle allocate
extents in a round-robin fashion between the files or will he fill one data
file and then pass to the another data file ?
Oracle will write to the datafiles in a round robin fashion. You can
create a tablespace with 3/5 datafile, and create atble, allocate extent,
see how oracle distribute it among different datafiles.
--
> Regards
> Zhu Chao
> www.cnoug.org <http://www.cnoug.org>
>
--
http://www.freelists.org/webpage/oracle-l
Received on Mon Aug 01 2005 - 05:30:19 CDT
