Advise on database setup

Hello everyone, I'm currently playing the role of begginer DBA at my job and I need some advise on how to optimize the layout of our Informix database. Currently we have an Informix 7.30.UC5, running on a SUN Enterprise 450 server, with solaris 2.6, 2 gig of physical memory and about 8 disks with the following layout: DISK SIZE -------------- ------ Primary disk A = 9 gigs Primary disk B = 9 gigs Primary disk C = 9 gigs Primary disk D = 18 gigs --------------- ------ Mirror disk A = 9 gigs Mirror disk B = 9 gigs Mirror disk C = 9 gigs Mirror disk D = 18 gigs My current page size is 2K: onstat -b: Informix Dynamic Server Version 7.30.UC5 -- On-Line -- Up 1 days 19:35:28 -- 231712 Kbytes Buffers address userthread flgs pagenum memaddr nslots pgflgs xflgs owner waitlist 0 modified, 0 resident, 100000 total, 131072 hash buckets, 2048 buffer size Due to the page size the largest chunk size I can have is 2 gig. Because of this limitation, disk partitions are laid out in the following manner: Disk A through C: ----------------- format: Current partition table (original): Total disk cylinders available: 4924 + 2 (reserved cylinders) Part Tag Flag Cylinders Size Blocks 0 unassigned wm 1 - 243 426.08MB (243/0/0) 872613 1 unassigned wm 244 - 1412 2.00GB (1169/0/0) 4197879 2 backup wu 0 - 4923 8.43GB (4924/0/0) 17682084 3 unassigned wm 1413 - 2581 2.00GB (1169/0/0) 4197879 4 unassigned wm 2582 - 3750 2.00GB (1169/0/0) 4197879 5 unassigned wm 3751 - 4919 2.00GB (1169/0/0) 4197879 6 unassigned wm 0 0 (0/0/0) 0 7 unassigned wm 0 0 (0/0/0) 0 Disk D ------ format: Current partition table (original): Total disk cylinders available: 7506 + 2 (reserved cylinders) Part Tag Flag Cylinders Size Blocks 0 unassigned wm 1 - 891 2.00GB (891/0/0) 4198392 1 unassigned wm 892 - 1782 2.00GB (891/0/0) 4198392 2 backup wu 0 - 7505 16.86GB (7506/0/0) 35368272 3 unassigned wm 1783 - 2673 2.00GB (891/0/0) 4198392 4 unassigned wm 2674 - 3564 2.00GB (891/0/0) 4198392 5 unassigned wm 3565 - 4455 2.00GB (891/0/0) 4198392 6 unassigned wm 4456 - 5346 2.00GB (891/0/0) 4198392 7 unassigned wm 5347 - 6237 2.00GB (891/0/0) 4198392 ------- Disk capacity: 16.86GB Disk available: 14.00GB = Wasted space-> 2.86 gigs * QUESTION: How can I increase the pagesize for the database so I could have a 4K pagesize, therefore allowing me to have 4 Gig chunks? From the manual, it's system dependent but from what I can tell, my hardware supports is able to support a larger pagesize, the command: "/usr/bin/pagesize" displays a pagesize of 8192 The current logical layout of my database looks like this: have in mind that all special dbspaces are located on the first slice d0s0 of each disk: DBSPACE SIZE LOCATION ------- ---- ------- rootdbs 420megs disk A d0s0 dbs00 2gb disk A d0s1 physdbs 400megs disk B d0s0 dbs01 2gb disk B d0s1 logdbs 420megs disk C d0s0 dbs03 2gb disk C d0s1 dbs02 2gb disk D d0s0 I have a total of two databases, one that is about 30 megs and the other one well, here it is: Size of Table(N) = numrows * rowsize (1) 79171321 *303 = 23,988,910,263 (2) 54173 * 78 = 4,225,494 (3) 16096*114 = 1,834,944 (4) 17291103 * 291= 5,031,710,973 (5) 55*276 = 15,180 (6) 91495086 * 30 = 2,744,852,580 (7) 104*260 = 27,040 (8) 16172214 *12 = 194,066,568 (9) 852559 * 71 = 60,531,689 (10) 854546 * 268 = 229,018,328 (11) 13440*134 = 1,800,960 ---------------------------------- 11 Tables = 32,256,994,019 bytes Average Table Size = 2,932,454,001 It took about 12 months for the tables to reach this label, therefore we intake about 90 megs a day worth of data. I would like tables #5, #6, #9, #4 to be optimized for speed, from what I can understand from the manual , I should be placing this tables in the middle cilinders of the disks, and also in their own dbspaces. MORE QUESTIONS 1- What should my extent sizes be? I read in some posting it should be 1/16 of the current size, others 1/10, what do you guys suggest? My plans are to make the first extent size the current size of the plus 1/16 of it's current size therefore: first extent = Currentsize + (CurrentSize/16) next extent = 1/16 2- I'm planning to turn "Buffered Logging" this database, is my physical and logical dbspaces large enough to handle it? (we do backups every night) 3- What's the deal with the DBSPACE, I know you use them to match the logical location of tables to their physical location on the disk, but besides this use, what commands the number of dbspaces? 4- How many logical logs should I have? The max amount of users we will ever have on the system is 20, from your formula I tell that the logical logs should be: Logical Log Size = 20 users * maxrows * 512 _ what does maxrows refer to? Is it to the maximun numbers of rows I will insert in a single transaction? Physlog = userthreads * max_log_pages_per_critical_section *4 Also the physical log seem to be similar to the logical log formula, but I'm a bit shady as to what the max log pages per critical section means. 5- How big should my rootdbs be now that I moved the logical logs and physycal logs out of them? I'm planning to create a tempdbs space only for temporary tables, should I use the rootdbs for that? I got a feeling it's not a wise thing to do, but I'm just a begginer. Well guys this was my little posting, hope I'm not asking for way too much out of ya, if you can make a suggestion, I would greatly appreciate it. Thank you for you time Julnio Vasquez