Diagnosing a slow Extract
Until now, we have discussed the performance of Replicat because this generally requires tuning, whether it be adjusting the integrated parameters or adding additional processes. Occasionally, however, the Extract process may be slow, but before we tune, we must diagnose. Typically, slow performance lies with I/O operations, but let's perform the following steps to find the root cause for our Extract running in the classic capture mode:
Firstly, collect the Extract's statistics using the
STATS
command:GGSCI (db12server01) 1> stats EOLTP01, totalsonly *, reportrate sec GGSCI (db12server01) 2> stats EOLTP01, totalsonly *, reportrate min
Copy the Extract's parameter file to a test parameter file as follows:
$ cp ./dirprm/EOLTP01.prm ./dirprm/ETEST.prm
Add the
TESTMAPPINGSPEED
parameter to the test Extract parameter file, as shown in the following code:TESTMAPPINGSPEED REPORTCOUNT EVERY 5000 RECORDS
Add the test Extract process group
ETEST
withbegin now
timestamp...