In order for you to improve the performance for this extractor you must do two things as per note 382329:
Create the index COEP~4 and update the index statistics. If you see that this is created, Check if it like the DB is
using COEP~1, check and update.
Change the entry in table BWOM_SETTINGS where PARAM NAME = OBJSELSIZE to have the PARAM VALUE = X.
The entry should look like this:
MANDT 300
OLTPSOURCE
PARAM NAME OBJSELSIZE
PARAM VALUE X
Also please implement note note 1119746.