> A general question about what "it should be" for good performance :
ATTENTION: rules of thumb are just that: rules of thumb and if they apply to your system is not granted. So, be aware as "your mileage may vary"!
> i have a database that always grows (quite nothing is deleted), due to regulary text files imports and human data entry.
>
> Actually, i have one volume of 10 Gb (where datas use half the size).
This is pretty small, although you may want to rething your volume layout.
> The database is stored on the production machine, that use a raw space on a "standard" disk.
> 1) would it be better to have more than one volume, but smaller, for example 1 Gb per volume ?
Very likely: yes.
MaxDB stores data in 8K pages spread over all available volumes. It does not allocate groups of pages (aka extents), but just single pages as the primary tree structure is a B*tree, just like the indexes.
With multiple volumes you enable a higher parallelity when accessing the volumes, since there is an I/O task for assigned to each volume there is.
> 2) I will have soon a new machine with raid 10 disks. Does it make sense to have more volumes too (on raw space) ?
If you mean by "raw space" Raw Devices - well, yes. From a DB point of view there's nothing better than Raw Devices are the database does its own caching.
For a setup like your's I'd propose to have volumes of, say 2 GB in size.
That way you can still add much space to the database later on and also have at least some degree of parallel I/O.
In general, you should measure where your peformance bottleneck is and change that.
Best regards,
Lars
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