一个奇怪的Oracle SQL Loader错误
今天在用Oracle SQL Loader导入文本文件时，发生了一个奇怪的问题，就是：我的输入文本文件dbim.dat放在oracle用户根目录（$HOME）下时，导入不成功；而将其放在/u01/app/oracle目录下时，则可以成功。
先来看失败的情况：
[oracle@ocp23c test]$ pwd
/home/oracle/test
[oracle@ocp23c test]$ ls -l dbim*
-rw-r--r-- 1 oracle oinstall 1748681 Jan 5 01:08 dbim.dat
-rw-r--r-- 1 oracle oinstall 2321 Jan 5 09:47 dbim.log
[oracle@ocp23c test]$ sqlldr ssb@orclpdb1 table=dbim
Password:
SQL*Loader: Release 23.0.0.0.0 - Production on Fri Jan 5 09:47:46 2024
Version 23.3.0.23.09
Copyright (c) 1982, 2023, Oracle and/or its affiliates. All rights reserved.
Express Mode Load, Table: DBIM
Path used: External Table, DEGREE_OF_PARALLELISM=AUTO
SQL*Loader-807: error loading table
ORA-29913: error while processing ODCIEXTTABLEOPEN routine
ORA-29400: data cartridge error
KUP-04040: file dbim.dat in SYS_SQLLDR_XT_TMPDIR_00000 not found
Help: https://docs.oracle.com/error-help/db/ora-29913/
Table DBIM:
0 Rows successfully loaded.
Check the log files:
dbim.log
dbim_%p.log_xt
for more information about the load.
[oracle@ocp23c test]$ ls -l dbim*
-rw-r--r-- 1 oracle oinstall 1748681 Jan 5 01:08 dbim.dat
-rw-r--r-- 1 oracle oinstall 2321 Jan 5 09:47 dbim.log
错误KUP-04040说，输入文件dbim.dat找不到，但这个文件明明就在当前目录。并且日志文件dbim.log也产生了，但是外部表日志文件dbim_%p.log_xt确实没有。
再来看下SQL Loader的日志文件：
[oracle@ocp23c test]$ cat dbim.log
SQL*Loader: Release 23.0.0.0.0 - Production on Fri Jan 5 09:47:46 2024
Version 23.3.0.23.09
Copyright (c) 1982, 2023, Oracle and/or its affiliates. All rights reserved.
Express Mode Load, Table: DBIM
Data File: dbim.dat
Bad File: dbim_%p.bad
Discard File: none specified
(Allow all discards)
Number to load: ALL
Number to skip: 0
Errors allowed: 50
Continuation: none specified
Path used: External Table
Table DBIM, loaded from every logical record.
Insert option in effect for this table: APPEND
Column Name Position Len Term Encl Datatype
------------------------------ ---------- ----- ---- ---- ---------------------
A FIRST * , CHARACTER
Generated control file for possible reuse:
OPTIONS(EXTERNAL_TABLE=EXECUTE, TRIM=LRTRIM)
LOAD DATA
INFILE 'dbim'
APPEND
INTO TABLE DBIM
FIELDS TERMINATED BY ","
(
A
)
End of generated control file for possible reuse.
created temporary directory object SYS_SQLLDR_XT_TMPDIR_00000 for path /home/oracle/test
enable parallel DML: ALTER SESSION ENABLE PARALLEL DML
creating external table "SYS_SQLLDR_X_EXT_DBIM"
CREATE TABLE "SYS_SQLLDR_X_EXT_DBIM"
(
"A" VARCHAR2(16)
)
ORGANIZATION external
(
TYPE oracle_loader
DEFAULT DIRECTORY SYS_SQLLDR_XT_TMPDIR_00000
ACCESS PARAMETERS
(
RECORDS DELIMITED BY NEWLINE CHARACTERSET US7ASCII
BADFILE 'SYS_SQLLDR_XT_TMPDIR_00000':'dbim_%p.bad'
LOGFILE 'dbim_%p.log_xt'
READSIZE 1048576
FIELDS TERMINATED BY "," LRTRIM
REJECT ROWS WITH ALL NULL FIELDS
(
"A" CHAR(255)
)
)
location
(
'dbim.dat'
)
)REJECT LIMIT UNLIMITED
executing INSERT statement to load database table DBIM
INSERT /*+ append parallel(auto) */ INTO DBIM
(
A
)
SELECT
"A"
FROM "SYS_SQLLDR_X_EXT_DBIM"
SQL*Loader-807: error loading table
ORA-29913: error while processing ODCIEXTTABLEOPEN routine
ORA-29400: data cartridge error
KUP-04040: file dbim.dat in SYS_SQLLDR_XT_TMPDIR_00000 not found
Help: https://docs.oracle.com/error-help/db/ora-29913/
dropping external table "SYS_SQLLDR_X_EXT_DBIM"
Table DBIM:
0 Rows successfully loaded.
Run began on Fri Jan 05 09:47:46 2024
Run ended on Fri Jan 05 09:47:52 2024
Elapsed time was: 00:00:05.40
CPU time was: 00:00:00.03
其中的临时目录对象SYS_SQLLDR_XT_TMPDIR_00000并没有问题。
百思不得其解，然后将dbim.dat放在另一个目录，再试一次，居然成功了。
$ sqlldr ssb@orclpdb1 table=dbim
Password:
SQL*Loader: Release 23.0.0.0.0 - Production on Fri Jan 5 09:39:07 2024
Version 23.3.0.23.09
Copyright (c) 1982, 2023, Oracle and/or its affiliates. All rights reserved.
Express Mode Load, Table: DBIM
Path used: External Table, DEGREE_OF_PARALLELISM=AUTO
Table DBIM:
158971 Rows successfully loaded.
Check the log files:
dbim.log
dbim_%p.log_xt
for more information about the load.
[oracle@ocp23c test]$ ls -l dbim*
-rw-r--r-- 1 oracle oinstall 497 Jan 5 09:39 dbim_28651.log_xt
-rw-r--r-- 1 oracle oinstall 1748681 Jan 5 01:08 dbim.dat
-rw-r--r-- 1 oracle oinstall 2078 Jan 5 09:39 dbim.log
我们看到，除了成功外，和上一个例子有所不同的是，外部表日志文件dbim_28651.log_xt也产生了。
所以，很明确，一定是权限的问题，而且是操作系统文件目录权限的问题。
和同事沟通后，总结原因如下，但目前还没有看到具体的文档说明：
- SQL Loader日志文件dbim.log是由sqlldr程序写的，所以权限是没有问题
- 对外部表的读取，以及写外部表日志的操作，是有数据库内部进程操作的，这个进程的owner在本例中是grid
这样就很好解释了，先看以下的输出：
[oracle@ocp23c ~]$ ls -ld $HOME/test
drwxr-xr-x 4 oracle oinstall 4096 Jan 5 09:47 /home/oracle/test
[oracle@ocp23c ~]$ ls -ld $HOME
drwx------ 9 oracle oinstall 4096 Jan 5 09:47 /home/oracle
[oracle@ocp23c ~]$ ls -ld /u01/app/oracle/test
drwxr-xr-x 2 oracle oinstall 4096 Jan 5 03:43 /u01/app/oracle/test
[oracle@ocp23c ~]$ ls -ld /u01/app/oracle
drwxr-xr-x 10 oracle oinstall 4096 Jan 5 01:23 /u01/app/oracle
[oracle@ocp23c ~]$ ls -ld /u01/app
drwxr-xr-x 7 root oinstall 4096 Dec 20 03:15 /u01/app
[oracle@ocp23c ~]$ ls -ld /u01
drwxr-xr-x 5 root oinstall 4096 Dec 20 03:14 /u01
可以看到，除了oracle用户，其它用户并不能进入其$HOME目录（因为缺省x权限），所以之前的找不到文件错误，是因为grid用户没有权限读取文件所在目录。而/u01/app/oracle目录则所有用户都可以进入。
教训：不要在oracle用户$HOME目录下放置数据文件，建议的数据文件目录可以是/u02下。
遗留问题：找到Oracle文档中对此问题的描述。
参考
- Permission issues when loading text file to external table
- Proper permissions to user for loading external tables
- File not found when querying external table.