Re: Knowledge Required

Chris Maethner writes: |I am concerned with the following question: | |I need to create a database with 8 million entries in |one table with about 300 byte per record. That makes |more or less 2.4 GB - more than an average disk. |Queries will always be using the unique index . |All this will be done using Informix Online on |a Sparc 10 with as much RAM as necessary. |All programs in ESQL/C. |Here we come to my questions to those, who have |experience in a similar environment: | |- what version of online would you consider stable and safe Ahem .... yes, well ... any one that doesn't have any bugs that will affect your application :)) Seriously, tho', I would go for a 5.x environment (probably the latest one out) as it gives you more tunables and the documentation should help you with arranging your disks and tuning etc. |- how many megabytes of ram would you consider for |minimum configuration 96 MB at a very wild guess - tho' this will depend on a lot of other things eg: what else is running on the machine, how big the kernel is, how much memory other things are using, what kind of reads/writes your application does ..... You could, however, monitor the situation and add RAM if necessary later (watch for page/swap outs). |- what would you think is a resonable estimate for response- | time There are so many variables involved in this that I don't think there IS a reasonable estimate - this will depend on number of users, coding, number of disks, type of disks, number of processsors, type of processor, whether I/O or CPU bound application etc etc etc..... |- can one table/index safely be split across several disks ? As far as I know, the only way you can split tables across disks is to create chunks in such a manner that once the first chunk is full (on, say, disk 1), then the next chunk is used (on, say, disk 2). Apparently you can split them more effectively when Online 6.1 arrives. Not sure if there is any way of controlling where indexes are stored. |- is it possible to use an raid-diskarray as raw device |for online ? if so, any experience with particular brand, |models ? Yes, it's possible - we have had miserable performance from a RAID 3 tho' - they are apparently designed for sequential data access (Graphics, BLOBS) rather than random access. Hope this helps, Richard Ridley DHL Asia Pacific