OnLine Performance

I am trying to increase the performance of our db server. My reading of the onstat -p output below is that there are to many sequential scans and thatthis has led to a high da-RA and low ixda-RA and idx-RA. The problem is that the applications connecting to this system are rather large and it will be difficult to isolate the sql and use set explain on them to establish which are leading to the sequential scans. Q. is there a way in OnLine 7.11UC1 to automatically establish which queries are using sequential scans, from the use of onaudit for example ? Q. can I tweak any of the onconfig parameters, also shown below, to increase performance ? Q. is the buffwrits - cache% shown below to low ? I increased my buffers in an attempt to bump it up, this worked jumping it from 60% to 71%. Q. is the RA_PAGES pages OK, to high / low ? we have about 16 concurrent queries. Thanks in advance for any help, Regards Jon Ridgway The Press Association ------------------ onstat -p : INFORMIX-OnLine Version 7.11.UC1 -- On-Line -- Up 1 days 17:20:19 -- 32600 Kbytes Profile dskreads pagreads bufreads %cached dskwrits pagwrits bufwrits %cached 602208 910036 20688662 97.09 43433 55129 156295 72.21 isamtot open start read write rewrite delete commit rollbk 11306148 322954 1474498 7995124 24597 44690 7875 19928 1 ovlock ovuserthread ovbuff usercpu syscpu numckpts flushes 0 0 0 5543.58 747.29 231 994 bufwaits lokwaits lockreqs deadlks dltouts ckpwaits compress seqscans 177804 0 55305271 0 0 27 4452 6055 ixda-RA idx-RA da-RA RA-pgsused lchwaits 121118 2122 144224 246702 18103 ------------------ onconfig (edited): RESIDENT 0 # Forced residency flag (Yes = 1, No = 0) MULTIPROCESSOR 0 # 0 for single-processor, 1 formulti-processor NUMCPUVPS 1 # Number of user (cpu) vps SINGLE_CPU_VP 1 # If non-zero, limit number of cpu vps toone NOAGE 0 # Process aging AFF_SPROC 0 # Affinity start processor AFF_NPROCS 0 # Affinity number of processors# Shared Memory Parameters LOCKS 6400 # Maximum number of locks BUFFERS 3200 # Maximum number of shared buffers NUMAIOVPS # Number of IO vps PHYSBUFF 32 # Physical log buffer size (Kbytes) LOGBUFF 32 # Logical log buffer size (Kbytes)LOGSMAX 16 # Maximum number of logical log files CLEANERS 1 # Number of buffer cleanerprocesses SHMBASE 0xa000000 # Shared memory base address SHMVIRTSIZE 8000 # initial virtual shared memory segmentsize SHMADD 8192 # Size of new shared memory segments (Kbytes) SHMTOTAL 0 # Total shared memory (Kbytes). 0=>unlimited CKPTINTVL 300 # Check point interval (in sec) LRUS 8 # Number of LRU queues LRU_MAX_DIRTY 60 # LRU percent dirty begin cleaning limit LRU_MIN_DIRTY 50 # LRU percent dirty end cleaning limit RA_PAGES 8 # Number of pages to attempt toread ahead RA_THRESHOLD 6 # Number of pages left before next group FILLFACTOR 80 # Fill factor for building indexes # method for OnLineto use when determining current time USEOSTIME 0 # 0: use internal time(fast), 1:get time from OS(slow) # Parallel Database Queries (pdq) PDQPRIORITY 0 # Degree of parallelism: 0 ... 100, # OFF => 0, LOW => 1, HIGH => 100 MAX_PDQPRIORITY 100 # Maximum allowed pdqpriority DS_MAX_QUERIES # Maximum number of decision supportqueries DS_TOTAL_MEMORY # Decision support memory (Kbytes) DS_MAX_SCANS 1048576 # Maximum number of decision support scans DATASKIP off # List of dbspaces to skip OPTCOMPIND 1 # To hint the optimizer NETTYPE tlitcp,8,20,NET # Override sqlhosts nettype parameters