Thanks for the effort, but as I said I prefer changing the buffer size than deflating/inflating data into new table.

Btw, I got info from the creator of DBD-InterBase (Edwin Pratomo): it is hardcoded, so just change the buffer's size (in dbdimp.h) MAX_SAFE_BLOB_LENGTH from 1000000 to desired value and re-compile:

. . .
#define MAX_SAFE_BLOB_LENGTH (1000000)
. . .
[download]

so, I did and it worked!

Regards, - Pet.