We are runing a critical batchjob in DB2 V8 fp4 for AIX on a p630 with
AIX 5.2
The job updates only 6 columns of the 100 columns in a 600 bytes wide
row.
The job is very IO bound because of log writes. We seems to be logging
full rows 600 bytes per updated row.
I thought DB2 should be clever enough to only log the modified columns
??
We also seems to write to the log with a lot of small writes, filemon
-v -O lf output indicates
that we write just 18 KB per IO.
The batchjob updates 290 000 rows (read/update) and it does just 58
commit
We can only reach a rate of 1000 rows/sec and we need to increase this.
I have tried to increase log buffer size, this is our values
DBHEAP 10000 logretain OFF LOGBUFSZ 4000
logprimary 14
logsecond 20 logfilsiz 8000
How can we get DB2 to log less and write more on each log write.
Mats Mohlin IBM Sweden