I am running into performance problems inserting into an indexed table, using Informix 11.50. The following timings for loading into compressed/uncompressed, indexed/non-indexed tables using dbload/HPL-Deluxe more illustrate the problem. The number of rows inserted is 6 million.
compressed/indexed/DBLoad or HPL/h:mm:ss.d
Y/Y/DBLoad/3:47:39.9
Y/N/DBLoad/0:10:58.1
N/Y/DBLoad/3:31:13.4
N/N/DBLoad/0:22:46.6
Y/Y/HPL/3:26:17.6
Y/N/HPL/0:08:31.7
N/Y/HPL/3:28:16.1
N/N/HPL/0:18:45.7
Why are the inserts into the indexed tables so much slower? I would expect some performance hit of course, but not this much. I want the indexes left intact during the load, hence my use of HPL in Deluxe mode rather than Express mode.
I'm using pretty much "out of the box" configuration parameters:
------------------------------------------------------------------------
onstat -c:
IBM Informix Dynamic Server Version 11.50.UC4 -- On-Line -- Up 4 days 17:59:
49 -- 38212 Kbytes
Configuration File: /opt/informix/informix.11.50_UC4/etc/onconfig.bcslinuxprod
ROOTNAME rootdbs
ROOTOFFSET 0
MIRROR 0
MIRRORPATH /opt/IBM/informix/tmp/demo_on.root_mirror
MIRROROFFSET 0
PHYSFILE 200000
PLOG_OVERFLOW_PATH /opt/IBM/informix/tmp
PHYSBUFF 128
LOGFILES 49
LOGSIZE 10000
DYNAMIC_LOGS 2
LOGBUFF 64
LTXHWM 70
LTXEHWM 80
CONSOLE /work1/stat/bcslinuxprod_console.log
TBLTBLFIRST 0
TBLTBLNEXT 0
TBLSPACE_STATS 1
DBSPACETEMP temp1db
SBSPACETEMP temp1sb
SBSPACENAME temp1sb
SYSSBSPACENAME temp1sbifmx
ONDBSPACEDOWN 2
NETTYPE ipcshm,1,50,CPU
LISTEN_TIMEOUT 60
MAX_INCOMPLETE_CONNECTIONS 1024
FASTPOLL 1
MULTIPROCESSOR 0
VP_MEMORY_CACHE_KB 0
SINGLE_CPU_VP 0
CLEANERS 8
AUTO_AIOVPS 1
DIRECT_IO 0
LOCKS 20000
DEF_TABLE_LOCKMODE page
RESIDENT 0
SHMBASE 0x44000000L
SHMVIRTSIZE 32656
SHMADD 8192
EXTSHMADD 8192
SHMTOTAL 0
SHMVIRT_ALLOCSEG 0,3
SHMNOACCESS
CKPTINTVL 300
AUTO_CKPTS 1
RTO_SERVER_RESTART 0
BLOCKTIMEOUT 3600
TXTIMEOUT 300
DEADLOCK_TIMEOUT 60
HETERO_COMMIT 0
TAPEBLK 32
TAPESIZE 0
LTAPEBLK 32
LTAPESIZE 0
BAR_DEBUG 0
BAR_MAX_BACKUP 0
BAR_RETRY 1
BAR_NB_XPORT_COUNT 20
BAR_XFER_BUF_SIZE 31
RESTARTABLE_RESTORE ON
BAR_PROGRESS_FREQ 0
BAR_BSALIB_PATH
BACKUP_FILTER
RESTORE_FILTER
BAR_PERFORMANCE 0
ISM_DATA_POOL ISMData
ISM_LOG_POOL ISMLogs
DD_HASHSIZE 31
DD_HASHMAX 10
DS_HASHSIZE 31
DS_POOLSIZE 127
PC_HASHSIZE 31
PC_POOLSIZE 127
STMT_CACHE 0
STMT_CACHE_HITS 0
STMT_CACHE_SIZE 512
STMT_CACHE_NOLIMIT 0
STMT_CACHE_NUMPOOL 1
USEOSTIME 0
STACKSIZE 32
ALLOW_NEWLINE 0
USELASTCOMMITTED NONE
FILLFACTOR 90
MAX_FILL_DATA_PAGES 0
ONLIDX_MAXMEM 5120
MAX_PDQPRIORITY 100
DS_MAX_QUERIES
DS_TOTAL_MEMORY
DS_MAX_SCANS 1048576
DS_NONPDQ_QUERY_MEM 128
DATASKIP
OPTCOMPIND 2
DIRECTIVES 1
EXT_DIRECTIVES 0
OPT_GOAL -1
IFX_FOLDVIEW 0
AUTO_REPREPARE 1
RA_PAGES 64
RA_THRESHOLD 16
EXPLAIN_STAT 0
IFX_EXTEND_ROLE 0
SECURITY_LOCALCONNECTION
UNSECURE_ONSTAT
ADMIN_USER_MODE_WITH_DBSA
ADMIN_MODE_USERS
SSL_KEYSTORE_LABEL
PLCY_POOLSIZE 127
PLCY_HASHSIZE 31
USRC_POOLSIZE 127
USRC_HASHSIZE 31
STAGEBLOB
OPCACHEMAX 0
ENCRYPT_HDR
ENCRYPT_SMX
ENCRYPT_CDR 0
ENCRYPT_CIPHERS
ENCRYPT_MAC
ENCRYPT_MACFILE
ENCRYPT_SWITCH
CDR_EVALTHREADS 1,2
CDR_DSLOCKWAIT 5
CDR_QUEUEMEM 4096
CDR_NIFCOMPRESS 0
CDR_SERIAL 0
CDR_DBSPACE
CDR_QHDR_DBSPACE
CDR_QDATA_SBSPACE
CDR_MAX_DYNAMIC_LOGS 0
CDR_SUPPRESS_ATSRISWARN
DRAUTO 0
DRINTERVAL 30
DRTIMEOUT 30
HA_ALIAS
DRIDXAUTO 0
LOG_INDEX_BUILDS
SDS_ENABLE
SDS_TIMEOUT 20
SDS_TEMPDBS
SDS_PAGING
REDIRECTED_WRITES 0
FAILOVER_CALLBACK
TEMPTAB_NOLOG 0
ON_RECVRY_THREADS 1
OFF_RECVRY_THREADS 10
DUMPSHMEM 1
DUMPGCORE 0
DUMPCORE 0
DUMPCNT 1
ALRM_ALL_EVENTS 0
STORAGE_FULL_ALARM 600,3
RAS_PLOG_SPEED 14900
RAS_LLOG_SPEED 742
EILSEQ_COMPAT_MODE 0
QSTATS 0
WSTATS 0
JVPJAVALIB /bin
JVPJAVAVM jvm
AUTO_LRU_TUNING 1
ROOTPATH /opt/IBM/informix/demo/server/online_root
MSGPATH /work1/stat/bcslinuxprod_online.log
TAPEDEV /dev/null
LTAPEDEV /dev/null
DBSERVERNAME bcslinuxprod
DBSERVERALIASES
SERVERNUM 0
ALARMPROGRAM /opt/IBM/informix/etc/alarmprogram.sh
DRLOSTFOUND /opt/IBM/informix/etc/dr.lostfound
BAR_ACT_LOG /work1/stat/bar_act.log
BAR_DEBUG_LOG /work1/stat/bar_debug.log
SYSALARMPROGRAM /opt/IBM/informix/etc/evidence.sh
DUMPDIR /work1/stat
JVPJAVAHOME /opt/IBM/informix/extend/krakatoa/jre
JVPHOME /opt/IBM/informix/extend/krakatoa/
JVPPROPFILE /opt/IBM/informix/extend/krakatoa/.jvpprops
JVPLOGFILE /opt/IBM/informix/demo/server/jvp.log
JVPCLASSPATH /opt/IBM/informix/extend/krakatoa/krakatoa.jar:/opt/IBM/informix/ex
tend/krakatoa/jdbc.jar
ROOTSIZE 200000
BUFFERPOOL size=2K,buffers=1000,lrus=8,lru_min_dirty=50.000000,lru_max_dirt
y=60.000000
VPCLASS cpu,num=1,noage
BTSCANNER num=1,threshold=5000,rangesize=-1,alice=6
UPDATABLE_SECONDARY 0
--------------------------------------------------------------------
Here is my table definition:
--------------------------------------------------------------------
create table "mdwilkie".noaa_sst_conventional_hpl_comp_24000000
(
type_of_observation integer,
source_of_observation integer,
dt datetime year to second,
latitude float,
longitude float,
sst float,
reliability integer,
solar_zenith_angle float,
satellite_zenith_angle float,
analyzed_field_sst float,
internal_error float,
solar_azimuth_angle float,
climatological_sst float,
beginning_row integer,
beginning_column integer,
avhrr_ch_1_average float,
avhrr_ch_2_average float,
avhrr_ch_3_average float,
avhrr_ch_4_average float,
avhrr_ch_5_average float,
space_view_ch_1 float,
space_view_ch_2 float,
space_view_ch_3 float,
ch_4_blackbody_temperature float,
ch_5_blackbody_temperature float,
year_of_observation integer
) extent size 16 next size 16 lock mode page;
start violations table for "mdwilkie".noaa_sst_conventional_hpl_comp_24000000
using noaa_sst_conventional_hpl_comp_24000000_vio, noaa_sst_conventional_hpl_comp_24000000_dia;
create index "mdwilkie".noaa_sst_conventional_hpl_comp_24000000_dt_idx
on "mdwilkie".noaa_sst_conventional_hpl_comp_24000000 (dt)
using btree in miscdbind;
create index "mdwilkie".noaa_sst_conventional_hpl_comp_24000000_latitude_idx
on "mdwilkie".noaa_sst_conventional_hpl_comp_24000000 (latitude)
using btree in miscdbind;
create index "mdwilkie".noaa_sst_conventional_hpl_comp_24000000_longitude_idx
on "mdwilkie".noaa_sst_conventional_hpl_comp_24000000 (longitude)
using btree in miscdbind;
--------------------------------------------------------------------------------
Note that my default dbspace (miscdbtab) is different from my index dbspace (miscdbind), but both are stored on the same disk (the only disk on my linux box). Also I'm using just 1 CPU.
Here are the last few lines from the log file:
-----------------------------------------------------------------------------
09:41:42 Maximum server connections 4
09:41:42 Checkpoint Statistics - Avg. Txn Block Time 0.000, # Txns blocked 1, Plog used 26253, Llog used 7
09:42:56 Checkpoint Completed: duration was 2 seconds.
09:42:56 Tue Jul 7 - loguniq 1610, logpos 0x26466a4, timestamp: 0x7c24d7c1 Interval: 12113
09:42:56 Maximum server connections 5
09:42:56 Checkpoint Statistics - Avg. Txn Block Time 0.000, # Txns blocked 2, Plog used 26253, Llog used 7
09:44:09 Checkpoint Completed: duration was 3 seconds.
09:44:09 Tue Jul 7 - loguniq 1610, logpos 0x264e4b0, timestamp: 0x7c2697f5 Interval: 12114
09:44:09 Maximum server connections 5
09:44:09 Checkpoint Statistics - Avg. Txn Block Time 0.000, # Txns blocked 1, Plog used 26253, Llog used 8
09:45:34 Checkpoint Completed: duration was 0 seconds.
09:45:34 Tue Jul 7 - loguniq 1610, logpos 0x2655560, timestamp: 0x7c285148 Interval: 12115
09:45:34 Maximum server connections 5
09:45:34 Checkpoint Statistics - Avg. Txn Block Time 0.000, # Txns blocked 1, Plog used 26253, Llog used 7
-----------------------------------------------------------------------
My linux box has the following description:
CPU: Intel Pentium D, 3.0 GHz, 2MB Cache, 32 bit
RAM: 2 GB
OS: Fedora Core 7
Here are the first few lines of output from "top":
-----------------------------------------------------------------------
top - 09:50:39 up 11 days, 23:10, 12 users, load average: 21.83, 21.41, 21.35
Tasks: 230 total, 1 running, 229 sleeping, 0 stopped, 0 zombie
Cpu(s): 2.8%us, 2.3%sy, 0.0%ni, 40.5%id, 54.2%wa, 0.0%hi, 0.2%si, 0.0%st
Mem: 2066880k total, 2015236k used, 51644k free, 14972k buffers
Swap: 2031608k total, 196k used, 2031412k free, 1559480k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
3982 informix 5 -10 59888 45m 43m S 5 2.2 39:00.35 oninit
3996 root 6 -10 59868 6464 5124 D 1 0.3 1:21.52 oninit
9939 informix 15 0 2340 1088 788 R 1 0.1 0:00.06 top
3988 root 6 -10 59876 7440 6096 D 0 0.4 1:49.16 oninit
3991 root 6 -10 59876 6916 5572 D 0 0.3 1:38.22 oninit
3992 root 6 -10 59876 6680 5336 D 0 0.3 1:33.69 oninit
3994 root 5 -10 59868 6508 5168 D 0 0.3 1:26.88 oninit
3995 root 5 -10 59876 6772 5428 D 0 0.3 1:24.17 oninit
3997 root 6 -10 59868 6276 4936 D 0 0.3 1:18.85 oninit
4001 root 5 -10 59868 6312 4972 D 0 0.3 1:10.82 oninit
4003 root 5 -10 59876 6388 5044 D 0 0.3 1:08.10 oninit
4004 root 6 -10 59868 6048 4708 D 0 0.3 1:06.35 oninit
4006 root 6 -10 59876 6356 5012 D 0 0.3 1:03.41 oninit
4007 root 6 -10 59868 6320 4980 D 0 0.3 1:01.70 oninit
------------------------------------------------------------------------
The machine appears to be heavily I/O bound.
I don't have the option of splitting table and index onto different disks, disabling the index during the load, or adding more CPU's (I'm not sure if this would make a difference anyway). Do I have any other options? Are there some specific configuration parameters that I should try adjusting?
Many thanks,
Mike
