figured out the solution myself - probably noone answered because it was too easy?
I thought I should post it here, because you were very friendly, Tim! Thanks for your help and keep up this good forum!
Simply use the following control file syntax:
Code: Select all
data LOBFILE(CONSTANT 'abc/vd-img.lob') VARRAWC(4,4096)
The file 'abc/vd-img.lob then needs to contain a (as specified by the first number in the varraw datatype) four-digit number specifying the length of the following image. Then the image follows (which, according to the control file, may not be longer than 4096 bytes). Then the size of the next image follows, followed, by the image, ... (and so on).
With a test on a Solaris9 two-processor machine removing the I/O overhead by putting 22000 image files into the single lob file I saved approx. 20% of load time. This increases even more if starting multiple loads in parallel. (I know, this depends very much on the used disks, the size of the images, ... and lots of other factors, but those 20% are already very nice).
Instead of using a constant file containing all the images it is (according to the documentation) also possible to specify the file in each row of the input data.
Best regards from sunny Black Forrest, Germany,