Re: anyway to optimize this query?

let's see... there are 61772773 rows in the table. The table is indexed on three fields, let's call it f1,f2,f3, it is a composite index, the reason I do that is because there is also a where clause in the query which uses all three fields as criterias. update satistics was performed. we are running 7.22 on solaris 2.6 with 2 p300 processors and 256 meg of rams. here are my onconfig file: ROOTNAME rootdbs # Root dbspace nameROOTPATH /usr/informix/dbspace/rootdbs ROOTOFFSET 0 # Offset of root dbspace into device (Kbytes) ROOTSIZE 125000 # Size of root dbspace (Kbytes)MIRROR 0 # Mirroring flag (Yes = 1, No = 0) MIRRORPATH # Path for device containing mirrored root MIRROROFFSET 0 # Offset into mirrored device (Kbytes)PHYSDBS rootdbs # Location (dbspace) of physical log PHYSFILE 10000 # Physical log file size (Kbytes) LOGFILES 8 # Number of logical log files LOGSIZE 10000 # Logical log size (Kbytes)MSGPATH /usr/informix/online.log # System message log file path CONSOLE /dev/null # System null message pathALARMPROGRAM /usr/informix/log_full.sh # Alarm program path TAPEDEV /dev/null # Tape device path TAPEBLK 16 # Tape block size (Kbytes) TAPESIZE 10240 # Maximum amount of data to put on tape (Kbytes) LTAPEDEV value # Log tape device path LTAPEBLK 16 # Log tape block size (Kbytes) LTAPESIZE 10240 # Max amount of data to put on log tape (Kbytes)STAGEBLOB # INFORMIX-OnLine/Optical staging area SERVERNUM 1 # Unique id corresponding to a OnLineinstance DBSERVERNAME Hamlet # Name of default database server DBSERVERALIASES Macbeth # List of alternate dbservernames DEADLOCK_TIMEOUT 60 # Max time to wait of lock in distributed env. RESIDENT 0 # Forced residency flag (Yes = 1, No = 0) MULTIPROCESSOR 1 # 0 for single-processor, 1 formulti-processor NUMCPUVPS 2 # Number of user (cpu) vps SINGLE_CPU_VP 0 # If non-zero, limit number of cpu vps toone NOAGE 1 # Process aging AFF_SPROC 0 # Affinity start processor AFF_NPROCS 0 # Affinity number of processors LOCKS 2000 # Maximum number of locks BUFFERS 37768 # Maximum number of shared buffers NUMAIOVPS 15 # Number of IO vps PHYSBUFF 32 # Physical log buffer size (Kbytes) LOGBUFF 32 # Logical log buffer size (Kbytes)LOGSMAX 10 # Maximum number of logical log files CLEANERS 4 # Number of buffer cleaner processes SHMBASE 0xa000000 # Shared memory base address SHMVIRTSIZE 8000 # initial virtual shared memory segment size SHMADD 8192 # Size of new shared memory segments (Kbytes) SHMTOTAL 0 # Total shared memory (Kbytes). 0=>unlimited CKPTINTVL 120 # Check point interval (in sec) LRUS 4 # Number of LRU queues LRU_MAX_DIRTY 60 # LRU percent dirty begin cleaning limit LRU_MIN_DIRTY 50 # LRU percent dirty end cleaning limit LTXHWM 50 # Long transaction high water markpercentage LTXEHWM 60 # Long transaction high water mark (exclusive) TXTIMEOUT 0x12c # Transaction timeout (in sec) STACKSIZE 32 # Stack size (Kbytes) OFF_RECVRY_THREADS 10 # Default number of offline workerthreads ON_RECVRY_THREADS 1 DRAUTO 0 # DR automatic switchover DRINTERVAL 30 # DR max time between DR buffer flushes (in sec) DRTIMEOUT 30 # DR network timeout (in sec) DRLOSTFOUND /tmp # DR lost+found file pathCDR_LOGBUFFERS 2048 # size of log reading buffer pool (Kbytes) CDR_EVALTHREADS 1,2 # evaluator threads (per-cpu-vp,additional) CDR_DSLOCKWAIT 5 # DS lockwait timeout (seconds) CDR_QUEUEMEM 4096 # Maximum amount of memory for any CDR queue (Kbytes) BAR_ACT_LOG /tmp/bar_act.log BAR_MAX_BACKUP 0 BAR_RETRY 1 BAR_NB_XPORT_COUNT 10 BAR_XFER_BUF_SIZE 31 RA_PAGES 80 # Number of pages to attempt to read ahead RA_THRESHOLD 20 # Number of pages left before next group DBSPACETEMP tempdb1 # Default temp dbspaces DUMPDIR /tmp # Preserve diagnostics in this directory DUMPSHMEM 1 # Dump a copy of shared memory DUMPGCORE 0 # Dump a core image using 'gcore' DUMPCORE 0 # Dump a core image (Warning:this aborts OnLine) DUMPCNT 1 # Number of shared memory or gcore dumps for FILLFACTOR 90 # Fill factor for building indexes USEOSTIME 0 # 0: use internal time(fast), 1: get time from OS(slow) MAX_PDQPRIORITY 12 # Maximum allowed pdqpriority DS_MAX_QUERIES 8 # Maximum number of decision support queries DS_TOTAL_MEMORY 36000 # Decision support memory (Kbytes) DS_MAX_SCANS 150 # Maximum number of decision support scans DATASKIP off # List of dbspaces to skip OPTCOMPIND 2 # To hint the optimizer ONDBSPACEDOWN 2 # Dbspace down option: 0 = CONTINUE, 1 = ABORT, 2 = WAITLBU_PRESERVE 0 # Preserve last log for log backup OPCACHEMAX 0 # Maximum optical cache size (Kbytes) HETERO_COMMIT 0 NETTYPE ipcshm,2,100,CPU # Configure poll thread(s) for nettype NETTYPE tlitcp,2,100,NET # Configure poll thread(s) for nettype ok, hmm, what else? that's about all I can think of. btw, I can't index all the grouped field. I am constructing the sql by a web page, everything is dynamic, they can randomly picked anyfields as output in any order, so indexing any group of fields inorder to speed up the groupby won't help most of them. thanks a lot. yan Obnoxio The Clown wrote: > >hi all: > > I have a 16 gig database, each record is contains 50 fields. > > I am running a query like this: > > > > select f1,f2....f15, sum(f40),sum(f41),sum(f42), sumf(43) > > group by f1,f2...f15> > > > as you see, i have to group about 15 fields and sum 4 other fields > >based on that group. > > now, it took me about 12 hours to run that query, my questions are: > > > > 1. is that normal speed or too slow? > > 2. if too slow, what are the suggestions to make it faster? > > This isn't really anything like enough information to make an informed > comment, but that has never stopped me in the past. :-) > > 1. UPDATE STATISTICS > 2. Indexes > 3. Pre-aggregate the data > 4. Tune the database server. > > If you ne