How many files can be stored in on directory? I don't know the answer. But when one directory have a lot of files, it will be very hard to operate, and may slow down the file access speed.
I performed two times of LOB recovery, all recovered in TXT mode. At this mode, each LOB values is stored as a single file in the directory where you run the AUL binary. For this two times, there are no so many LOB rows, the first time has about 12000 LOB values, the second time has about 15000 LOB values, so there is no problem for all of them are stored in one directory.
But how about there are millions of LOB values? I add a new option to AUL to distribute the LOB files among different subdirectories. The option name is "MAXLOBDIR" with default value 500 (The maximum value you can give is 2000). Then the LOB files will be stored in different directories, which can support millions of LOB values recovery, the subdirectory name will look like "LOBxxxx" (xxxx is four digit). For example :
AUL> set MAXLOBDIR 1000
Current MAXLOBDIR is : 1000
AUL>
Now perform the LOB recovery, and check the current directory.
C:\MYDUL\LOBREC>ls
AULCOL.TXT LOB0245 LOB0394
AULOBJ.TXT LOB0246 LOB0395
AULTAB.TXT LOB0247 LOB0396
AULUSR.TXT LOB0248 LOB0397
LOB0212 LOB0377 LOB0398
LOB0213 LOB0378 LOB0399
LOB0214 LOB0379 LOB0400
LOB0215 LOB0380 LOB0402
LOB0216 LOB0381 LOB0403
LOB0233 LOB0382 LOB0404
LOB0234 LOB0383 LOB0405
LOB0235 LOB0384 LOB0406
LOB0236 LOB0386 LOB0407
LOB0237 LOB0387 LOB0408
LOB0238 LOB0388 LOB0413
LOB0239 LOB0389 T_LOBTEST_sqlldr.ctl
LOB0240 LOB0390 T_LOBTEST_syntax.sql
LOB0242 LOB0391 aul4b.exe
LOB0243 LOB0392 lobtest.txt
LOB0244 LOB0393 t_lobtest.txt
I unload about 5000 LOB values in the example, it looks much better than store all of them in one directory.