paul wrote:
Hi,
i want to know if this is better to split a tablespace into several
containers while the database are on san disk.
Assuming you have DB2_PARALLEL_IO set properly (to enable DB2 to issue
multiple I/O requests to each container) then the answer is no.
Spreading your tablespace across multiple containers in the same
file system will result in I/O contention at the disk level.
Use 1 container per RAID array in the SAN device (note, multiple LUNs
may exist on a single RAID array, so make sure you understand the
mapping from file system -LUN -RAID array).
And how can i configure optimally the values for prefetch and extend ?
Extent size should be set to the strip size (or a multiple thereof) of
the RAID arrays in your SAN device. Prefetch should be set to ensure
that all disks are serving data for a prefetch request.