Tar and multiple volumes

Question

Guys,
I am using a SunOS 5.7 Generic_106541-09 sun4u sparc SUNW,Ultra-Enterprise, and when I try to copy files into a tape with "tar", I receive a message "unexpected EOF".
In other Unix, is possible to use the option "-e" (tar -cvfe) for using multiple volumes. What can I do with Solaris?
Thanks,
Marcelo V. Paula
[email protected]

Answer 1

Hi Frank,
as usual in case of such rather wide range question the correct answer is: it depends.
It depends with version of SAP DB/MaxDB you're using.
It also depends if a HASH JOIN is employed for this join (depends on data volume and db parameter setup -  OK for this join it's rather unlikely).
It's furthermore dependent on the configuration of parallel join feature and the availability of server tasks for this. As only one session at a time can use parallel join the very same statement may be handled in parallel one time and "serial" the other time.
So in the best case (no other query running parallel join) the join will be handled in parallel.
In the worst case, the query (logical I/O) will be done serial but nevertheless: we're still doing asynchronous I/O over striped datavolumes. So whenever a page is not in the cache the session won't block to wait until the I/O is done.
A deeper insight can be gained by attending the MaxDB Internals training offered by SAP. In that training many topics are covered in-depth, including the effects of database parameters and how (some) statements are processed.
Hope that helps a bit,
Lars