I had earlier read that LOAD REPLACE with DUMMY works faster as compared to DELETE * from table incase the volume of data is very large.
In our shop(with 300+ tablespaces with each tablespace housing one table), DELETE * from table was earlier being used. To improve the performance, I tried to use a LOAD REPLACE with DUMMY but to my surprise the job ran at a much slower speed than what it earlier used to run with. I ran the original job (the one with DELETE * from table) and the one with my changes (LOAD REPLACE with DUMMY) in parallel on two different databases. The original job completed in 8 minutes whereas the one with my changes finished in 35 minutes.
Here is one of the LOAD statements that I provided in SYSIN:
LOAD DATA REPLACE LOG NO INDDN SYSREC00 NOCOPYPEND INTO TABLE ABC.TABLE1;
Can anyone please help me understand why the performance must have degraded ?