Laurent Schneider
What is the instance name?
If your Oracle SID doesn’t match your instance name in init.ora, this is quite confusing.
Check my previous post, what is sid in oracle
In the instance_name column of the view v$instance, as well as in USERENV context, it matches the ORACLE_SID of the underlying operating system.
SQL> var ORACLE_SID varchar2(9)
SQL> set autoprint on
SQL> exec dbms_system.get_env('ORACLE_SID',:ORACLE_SID)
PL/SQL procedure successfully completed.
ORACLE_SID
------------
ORA001
SQL> select sys_context('USERENV','INSTANCE_NAME') from dual;
SYS_CONTEXT('USERENV','INSTANCE_NAME')
---------------------------------------
ORA001
SQL> select instance_name from v$instance;
INSTANCE_NAME
----------------
ORA001
SQL>
This is not the same as the init.ora parameter
SQL> select name, value, description from v$parameter where name='instance_name'; NAME VALUE DESCRIPTION ------------- --------- ---------------------------------------- instance_name INS001 instance name supported by the instance SQL>
The instance_name doesn’t have to match anything. It’s of relevance if you use ADR. And you probably do. Background dump dest and family are deprecated now. In your ADR docu you’ll read
{ORACLE_BASE}/diag/rdbms/{DB_UNIQUE_NAME}/{SID}/trace
But this SID is actually your init.ora instance name. And not your ORACLE_SID.
What is SID in Oracle ?
In the doc you’ll find, it’s the Oracle system identifier.
Okay, let’s imagine the following
Environment:
ORACLE_SID=ORA001
init.ora:
DB_NAME=DB001 DB_UNIQUE_NAME=UNI001 INSTANCE_NAME=INS001 SERVICE_NAMES=SVC001,SVC002 DB_DOMAIN=EXAMPLE.COM GLOBAL_NAMES=false
database:
SQL> select * from GLOBAL_NAME; GLO001.example.com
listener.ora:
SID_LIST_LISTENER = (SID_LIST = (SID_DESC = (GLOBAL_NAME=GLO001.EXAMPLE.COM) (SID_NAME=ORA001) ) )
What is my SID? Actually there is more than one correct answer.
In the environment, Oracle SID is ORA001. This matches SID_NAME in listener.ora. It does not have to match database name, unique name, global name or instance_name.
$ lsnrctl services Services Summary... Service "GLO001.EXAMPLE.COM" has 1 instance(s). Instance "ORA001", status UNKNOWN, has 1 handler(s) for this service... Handler(s): "DEDICATED" established:7 refused:0 LOCAL SERVER
As the instance is not running, I have only my listener.ora static connections.
The SERVICE_NAME is GLO001.EXAMPLE.COM and the SID is ORA001.
$ sqlplus "sys/***@ (DESCRIPTION= (ADDRESS= (PROTOCOL=TCP) (HOST=SRV001) (PORT=1521) ) (CONNECT_DATA= (SERVICE_NAME=GLO001.EXAMPLE.COM) ) )" as sysdba Connected to an idle instance. SQL> $ sqlplus "sys/***@ (DESCRIPTION= (ADDRESS= (PROTOCOL=TCP) (HOST=SRV001) (PORT=1521) ) (CONNECT_DATA= (SID=ORA001) ) )" as sysdba Connected to an idle instance. SQL>
Let’s start
SQL> startup
and check my services
$ lsnrctl services Services Summary... Service "SVC001.EXAMPLE.COM" has 1 instance(s). Instance "INS001", status READY, has 1 handler(s) for this service... Handler(s): "DEDICATED" established:0 refused:0 state:ready LOCAL SERVER Service "SVC002.EXAMPLE.COM" has 1 instance(s). Instance "INS001", status READY, has 1 handler(s) for this service... Handler(s): "DEDICATED" established:0 refused:0 state:ready LOCAL SERVER Service "UNI001.EXAMPLE.COM" has 1 instance(s). Instance "INS001", status READY, has 1 handler(s) for this service... Handler(s): "DEDICATED" established:0 refused:0 state:ready LOCAL SERVER Service "GLO001.EXAMPLE.COM" has 1 instance(s). Instance "ORA001", status UNKNOWN, has 1 handler(s) for this service... Handler(s): "DEDICATED" established:13 refused:0 LOCAL SERVER The command completed successfully
I know have 4 service names :
- The global name in listener.ora
- the unique name in init.ora
- both service name in init.ora
And 2 sid
- The SID in listener.ora
- The instance name in init.ora
While we often have sid = oracle_sid = service_name = service_names = global_name = instance_name = db_name = db_unique_name, if you switch from SID to SERVICE_NAME, this could be help to identify legacy application.
If you read the doc carefully, you may have noticed the SID is no longer documented as a valid clause of CONNECT_DATA in 11g and 12c
In 10gR2 :
http://docs.oracle.com/cd/B19306_01/network.102/b14213/tnsnames.htm#i477921
Use the parameter SID to identify the Oracle8 database instance by its Oracle System Identifier (SID). If the database is Oracle9i or Oracle8, use the SERVICE_NAME parameter rather than the SID parameter.
This is probably a documentation bug, I would rephrase this as If the database is Oracle9i or Oracle8i or later.
In 11g and 12c, the comment disappeared. Oracle 8i was released last century, but SID didn’t completly disappear from tnsnames. Yet.
duplicate to a future date
If you work with large databases, you often wait way to long for the clones. Typically you want to duplicate a 10TB database to production timestamp 9am, and you start at 9am and then you wait for hours.
Is it possible to start the clone, let’s say, at midnight, and set until time 9am?
No! You’ll get
RMAN-06617: UNTIL TIME (2016-05-21 09:00:00) is ahead of last NEXT TIME in archived logs (2016-05-20 23:58:52)
But… you could start to restore the datafiles at midnight.
sqlplus sys/***@db02 as sysdba <<EOF
alter system set db_name='DB01' scope=spfile;
alter system set db_unique_name='DB02' scope=spfile;
startup force nomount
EOF
rman target sys/***@db01 auxiliary sys/***@db02 <<EOF
restore clone primary controlfile;
alter clone database mount;
run {
set newname for datafile 1 to
"/db02/system01.dbf";
set newname for datafile 2 to
"/db02/sysaux01.dbf";
set newname for datafile 3 to
"/db02/undotbs1_02.dbf";
set newname for datafile 4 to
"/db02/users01.dbf";
restore clone database
;
}
EOF
This is exactly when RMAN does when you issue a duplicate. You could use the supported RESTORE command instead of the unsupported RESTORE CLONE command. But then it’ll get a bit more complex as you need to find out the location of your backup and so on.
At 9am, you issue your duplicate, and you’ll see
skipping datafile 1; already restored to file /db02/system01.dbf skipping datafile 2; already restored to file /db02/sysaux01.dbf skipping datafile 3; already restored to file /db02/undotbs1_02.dbf skipping datafile 4; already restored to file /db02/users01.dbf
You just saved nine hours 
column width change in 12c
In 11g I used to have 30 characters width in my dictionary
SQL> select table_name, column_name from user_tab_columns; TABLE_NAME COLUMN_NAME ------------------------------ ------------------------------ BONUS COMM BONUS SAL BONUS JOB BONUS ENAME DEPT LOC DEPT DNAME DEPT DEPTNO EMP DEPTNO EMP COMM EMP SAL EMP HIREDATE TABLE_NAME COLUMN_NAME ------------------------------ ------------------------------ EMP MGR EMP JOB EMP ENAME EMP EMPNO SALGRADE HISAL SALGRADE LOSAL SALGRADE GRADE 18 rows selected.
Which was pretty nice to read with no setting.
Now in 12c it is ugly enought to make your eyes tired
SQL> select table_name, column_name from user_tab_columns; TABLE_NAME ------------------------------------------------------------------------------------------------------------------------ COLUMN_NAME ------------------------------------------------------------------------------------------------------------------------ DEPT DEPTNO DEPT DNAME DEPT LOC TABLE_NAME ------------------------------------------------------------------------------------------------------------------------ COLUMN_NAME ------------------------------------------------------------------------------------------------------------------------ EMP EMPNO EMP ENAME EMP JOB TABLE_NAME ------------------------------------------------------------------------------------------------------------------------ COLUMN_NAME ------------------------------------------------------------------------------------------------------------------------ EMP MGR EMP HIREDATE EMP SAL TABLE_NAME ------------------------------------------------------------------------------------------------------------------------ COLUMN_NAME ------------------------------------------------------------------------------------------------------------------------ EMP COMM EMP DEPTNO BONUS ENAME TABLE_NAME ------------------------------------------------------------------------------------------------------------------------ COLUMN_NAME ------------------------------------------------------------------------------------------------------------------------ BONUS JOB BONUS SAL BONUS COMM TABLE_NAME ------------------------------------------------------------------------------------------------------------------------ COLUMN_NAME ------------------------------------------------------------------------------------------------------------------------ SALGRADE GRADE SALGRADE LOSAL SALGRADE HISAL 18 rows selected. SQL>
This is due to a change of the width of the underlying column in the dictionary. Probably a good-news for our data modeling colleagues that it may be 128 in future.
But currently it is only 30 characters in 12c. So why not format it correctly ?
Simply add the format in $ORACLE_HOME/sqlplus/admin/glogin.sql
col TABLE_NAME for a30 col COLUMN_NAME for a30
DISCLAIMER: it’s fine to add UNIQUE_KEY_LEVEL_NAME or REFERENCED_TRIGGER_NAME, but you may have application tables that have columns called OWNER or USER, it is probably safer to not assume they are all smaller than 30 chars, so don’t add common names.
Drop table cascade and reimport
Happy new year
Today I had to import a subset of a database and the challenge was to restore a parent table without restoring its children. It took me some minutes to write the code, but it would have taken days to restore the whole database.
CREATE TABLE t1( c1 NUMBER CONSTRAINT t1_pk PRIMARY KEY); INSERT INTO t1 (c1) VALUES (1); CREATE TABLE t2( c1 NUMBER CONSTRAINT t2_t1_fk REFERENCES t1, c2 NUMBER CONSTRAINT t2_pk PRIMARY KEY); INSERT INTO t2 (c1, c2) VALUES (1, 2); CREATE TABLE t3( c2 NUMBER CONSTRAINT t3_t2_fk REFERENCES t2, c3 NUMBER CONSTRAINT t3_pk PRIMARY KEY); INSERT INTO t3 (c2, c3) VALUES (2, 3); CREATE TABLE t4( c3 NUMBER CONSTRAINT t4_t3_fk REFERENCES t3, c4 NUMBER CONSTRAINT t4_pk PRIMARY KEY); INSERT INTO t4 (c3, c4) VALUES (3, 4); COMMIT; expdp scott/tiger directory=DATA_PUMP_DIR dumpfile=scott.dmp reuse_dumpfiles=y
Now what happen if I want to restore T2 and T3 ?
If possible, I check the dictionary for foreign keys from other tables pointing to T2 and T3.
SELECT constraint_name
FROM user_constraints
WHERE (r_constraint_name) IN (
SELECT constraint_name
FROM user_constraints
WHERE table_name IN ('T2', 'T3'))
AND table_name NOT IN ('T2', 'T3');
TABLE_NAME CONSTRAINT_NAME
------------------------------ ------------------------------
T4 T4_T3_FK
T4 points to T3 and T4 has data.
Now I can drop my tables with the cascade options
drop table t2 cascade constraints; drop table t3 cascade constraints;
Now I import, first the tables, then the referential constraints dropped with the cascade clause and not on T2/T3.
impdp scott/tiger tables=T2,T3 directory=DATA_PUMP_DIR dumpfile=scott.dmp impdp scott/tiger "include=ref_constraint:\='T4_T3_FK'" directory=DATA_PUMP_DIR dumpfile=scott.dmp
It’s probably possible to do it in one import, but the include syntax is horrible. I tried there
Licensing Cloud Control
I just read the Enterprise Manager Licensing Information User Manual today. They are a lot of packs there, and you may not even know that autodiscovering targets is part of the lifecycle management pack or that blackouts are part of the diagnostic pack.
Have a look
powershell odbc sybase
Oracle goes there ==> …/oracle-odbc-hello-world-with-powershell.html
To test Sybase ODBC driver with Powershell, it’s not much different
- configure the DsN with odbcconf or %SYSTEMROOT%\SysWOW64\odbcconf for the 32bits drivers under Windows 64.
- test it, same as in Oracle. If you need to test the 32bits drivers under 64bits windows, use the 32bits powershell %SystemRoot%\syswow64\WindowsPowerShell\v1.0\powershell.exe
cmd /c "%SYSTEMROOT%\SysWOW64\odbcconf.exe /a {configdsn ""Adaptive Server Enterprise"" ""DSN=helloworld|database=mydb|port=25000|server=srv01""}"
The name of the driver is important. It is probably also called “Adaptive Server Enterprise” on your machine.
$conn = New-Object data.odbc.odbcconnection
$conn.ConnectionString = "dsn=helloworld;uid=scott;pwd=tiger"
$conn.Open()
(new-Object Data.Odbc.OdbcCommand("select 'Hello World'",$conn)).ExecuteScalar()
$conn.close()
generate safe passwords
This is probably ambitious and I’ll start with a disclaimer, there is no such thing.
But ok, we know that system/manager isn’t
Apart from system/manager, there are hundreds of weak passwords that are commonly used and easy to guess.
On your database server, after a few tries, the account is lock. And maybe the attacker is detected by then.
So the worst passwords are the default passwords and passwords like oracle.
To enforce good passwords, we have verify functions, like ora12c_strong_verify_function in 12c, that checks for mixed case, special characters, etc. One may prefer to write his own and not disclose what it exactly checks.
In that function in rdbms admin, it states The maximum length of any DB User password is 128 bytes. but it’s 30 character in most cases.
If you have failed login attends of 10, chosing eleven as a password does not make it safe. If the attacker got’s the user metadata, you are screwed in no time. In Oracle 4, it’s clear text. In 7-10, it’s a doubled-DES unsalted with a fixed disclosed key encryption. There any dictionary attack takes milliseconds, and a 6 character password in sub-second. It’s got better in 11, where SHA1 could take weeks to years to have a 8 char password. Depending on its complexity. In 12c, generating a hash cost lot’s of cpu cycle, so it is no longer possible to test millions of password per second, even with the strongest hardware.
But to get a good password it is recommended and often required to use digit / letters / special signs / mixed case and no dictionary word.
I have made a small password generator for my reader using dbms_random.string, which generates pseudorandom string. It is best to use the cryptographically secure dbms_crypto.randombytes, but then you must still get a password that you can type. It should also be possible to use unicode if you like. And depending where you are going to use it, it is sometimes safer to not use signs like * or ‘ because, who know’s, your password may produce an error and end up in a logfile.
Okay, I wrote a small function that generates a 10-char string and verify it with the 12c strong verifier. And loop until one is good enough.
The chance that a random password is manager is pretty low, but it is probably best to check you got not only safe random, but also strong string
-- @?/rdbms/admin/catpvf
CREATE OR REPLACE FUNCTION pw (username VARCHAR2,
old_password VARCHAR2 DEFAULT NULL)
RETURN VARCHAR2
IS
p VARCHAR2 (30);
c BOOLEAN := FALSE;
i NUMBER := 0;
BEGIN
WHILE NOT c AND i < 1000
LOOP
p := DBMS_RANDOM.string ('P', 10);
i := i + 1;
BEGIN
c := sys.ora12c_strong_verify_function (username, p, old_PASSWORD);
EXCEPTION
WHEN OTHERS
THEN
NULL;
END;
END LOOP;
RETURN p;
END;
/
SELECT pw ('SCOTT', 'TIGER') FROM DUAL;
#gA~82NxBv
This could well be a good initial expired password for your user. Later the user will find something easier to remember
Generate 11g password hash
An easy way to generate a value string from the ssl is to use openssl
Let’s take a random salt of ABCDEFGHIJ. The length of 10 is important.
The hexadecimal representation is -41-42-43-44-45-46-47-48-49-4A-
$ echo "SafePassw0rDABCDEFGHIJ\c" | openssl dgst -sha1
(stdin)= 47cc4102144d6e479ef3d776ccd9e0d0158842bb
With this hash, I can construct my value
SQL> create user testuser identified by values 'S:47CC4102144D6E479EF3D776CCD9E0D0158842BB4142434445464748494A';
User created.
SQL> grant create session to testuser;
Grant succeeded.
SQL> conn testuser/SafePassw0rD
Connected.
If you prefer PL/SQL over shell, use DBMS_CRYPTO
SQL> exec dbms_output.put_line('S:'||dbms_crypto.hash(utl_raw.cast_to_raw('SafePassw0rDABCDEFGHIJ'),dbms_crypto.HASH_SH1)||utl_raw.cast_to_raw('ABCDEFGHIJ'))
S:47CC4102144D6E479EF3D776CCD9E0D0158842BB4142434445464748494A
PL/SQL procedure successfully completed.
In 12c there is also a “T” String. According to the doc
The cryptographic hash function used for generating the 12C verifier is based on a de-optimized algorithm involving PBKDF2 and SHA-512.
delete all data
How do you delete all data? The simplistic approach would be to truncate all tables
SQL> select table_name from user_tables;
TABLE_NAME
----------
T1
SQL> truncate table t1;
Table truncated.
You cannot truncate if you have referential integrity constraints.
SQL> truncate table t2;
ORA-02266: unique/primary keys in table
referenced by enabled foreign keys
Ok, let’s disable the RIC
SQL> select table_name, constraint_name
from user_constraints
where constraint_type='R';
TAB CONSTRAINT
--- ----------
T3 SYS_C00107
SQL> alter table t3 disable constraint SYS_C00107;
Table altered.
SQL> truncate table t2;
Table truncated.
SQL> truncate table t3;
Table truncated.
You cannot truncate cluster tables
SQL> truncate table t4;
ORA-03292: Table to be truncated is part of a cluster
Cluster tables could be dropped with TRUNCATE CLUSTER.
SQL> select cluster_name from user_clusters;
CLUSTER_NAME
------------
C
SQL> truncate cluster c;
Cluster truncated.
The code above doesn’t work with Partitioned cluster (12.1.0.2) because it was not properly implemented at the time of the writing.
Check Bug 20284579 : CAN NOT QUERY DYNAMIC CLUSTER PARTITIONS
For reference partitioning, it is not possible to disable the foreign key
SQL> alter table t6 disable constraint fk;
ORA-14650: operation not supported for
reference-partitioned tables
In 12c, if the foreign key is defined with ON DELETE CASCADE, you can truncate cascade the parent.
SQL> select table_name, REF_PTN_CONSTRAINT_NAME
from user_part_tables
where partitioning_type='REFERENCE';
TAB REF
--- ---
T6 FK
SQL> select r_constraint_name, delete_rule
from user_constraints
where constraint_name='FK';
R_CON DELETE_RULE
----- -----------
PK CASCADE
SQL> select table_name
from user_constraints
where constraint_name='PK';
TAB
---
T5
SQL> truncate table t5 cascade;
Table truncated.
But if one of child or child-child table is using reference partitioning without the ON DELETE CASCADE, then the parent or grand-parent could not be truncated. And truncate cascade for reference partitioning is not documented (yet).
But there is very nice alternative to TRUNCATE called is DELETE
SQL> select table_name, REF_PTN_CONSTRAINT_NAME
from user_part_tables
where partitioning_type='REFERENCE';
TAB REF
--- ---
T8 FK
SQL> select r_constraint_name, delete_rule
from user_constraints
where constraint_name='FK';
R_CON DELETE_RULE
----- -----------
PK NO ACTION
SQL> select table_name
from user_constraints
where constraint_name='PK'
TAB
---
T7
SQL> truncate table t7 cascade;
ORA-14705: unique or primary keys referenced by enabled foreign keys in table "SCOTT"."T8"
SQL> truncate table t8;
Table truncated.
SQL> delete from t7;
2 rows deleted
To get the tables in the right order, parent tables after children, you can do some hierarchical query and then order by rownum desc, a construct I’m using for the first time I confess. Note the leaf tables are truncable.
select c_owner owner, child table_name
FROM
(
SELECT
p_OWNER, parent, nvl(c_owner, a.owner) c_owner,
nvl(child, a.table_name ) child
FROM
(
SELECT
PT.OWNER P_owner, pt.table_name parent,
pt2.owner c_owner, pt2.table_name child
FROM all_part_tables pt
JOIN all_constraints c
ON pt.OWNER = c.owner
AND PT.TABLE_NAME = c.table_name
AND c.constraint_type = 'P'
AND c.status = 'ENABLED'
JOIN all_constraints r
ON r.r_owner = c.owner
AND r.r_constraint_name = c.constraint_name
AND r.constraint_type = 'R'
AND r.status = 'ENABLED'
JOIN all_part_tables pt2
ON r.owner = pt2.owner
AND r.constraint_name = pt2.REF_PTN_CONSTRAINT_NAME
AND pt2.partitioning_type = 'REFERENCE'
) t
RIGHT JOIN all_tables a
ON child = table_name and a.owner = T.c_OWNER
)
where connect_by_isleaf=0
CONNECT BY parent = PRIOR child and p_owner=PRIOR c_owner
start with parent is null
order by rownum desc;
OWNER TAB
----- ---
SCOTT T10
SCOTT T9
Note the query above is very slow. If dictionary-performance is an issue, maybe we could delete all tables and catch exceptions and loop until all tables are empty
SQL> delete from t9;
ORA-02292: integrity constraint (SCOTT.F10) violated - child record found
SQL> delete from t10;
ORA-02292: integrity constraint (SCOTT.F11) violated - child record found
SQL> delete from t11;
1 row deleted.
SQL> delete from t9;
ORA-02292: integrity constraint (SCOTT.F10) violated - child record found
SQL> delete from t10;
1 row deleted.
SQL> delete from t11;
0 row deleted.
SQL> delete from t9;
1 row deleted.
SQL> delete from t10;
0 row deleted.
SQL> delete from t11;
0 row deleted.
SQL> delete from t9;
0 row deleted.
SQL> delete from t10;
0 row deleted.
SQL> delete from t11;
0 row deleted.
If you have close to zero reference-partitioning table, this approach will be more efficient.
tracefile tim to readable date format
In trace file, the time is recorded, this could be used to measure time between two timestamps
But how do you convert 31796862227375 to a human format?
This is how I proceeded :
SQL> oradebug SETMYPID Statement processed. SQL> oradebug tracefile_name /u01/log/oracle/diag/rdbms/db01/DB01/trace/DB01_ora_32440740.trc SQL> alter session set nls_date_format='YYYY-MM-DD_HH24:MI:SS' sql_trace=true; Session altered. SQL> select '&_DATE','Start' from dual; 2015-09-23_13:17:50 Start SQL> select '&_DATE','End' from dual; 2015-09-23_13:18:38 End SQL> alter session set sql_trace=false; Session altered.
I use the sqlplus variable _date and waited about a minute between the select’s.
Now let’s look at the trace
PARSING IN CURSOR #4859519800 tim=31796814530524 select '2015-09-23_13:17:50','Start' from dual PARSING IN CURSOR #4859511384 tim=31796862227375 select '2015-09-23_13:18:38','End' from dual
Note the tim=
Between 13:17:50 and 13:18:38 I have 48 seconds; the difference between 31796862227375 and 31796814530524 is 47696851, roughly 48 millions of microseconds.
So the time on this specific version of Oracle is in microseconds.
Now if I substracted 31796862227375 from 2015-09-23_13:17:50 and I get 2014-09-20_12:50:08 on this specific instance.
So to convert tim= to human readable date, I simply add tim microseconds to Sep 20, 2014, 12:50:08.
job_name cannot be null
exec dbms_scheduler.create_job(job_name=>null,job_type=>'PLSQL_BLOCK',job_action=>'BEGIN NULL; END;')
ORA-27451: JOB_NAME cannot be NULL
ORA-06512: at "SYS.DBMS_ISCHED", line 146
ORA-06512: at "SYS.DBMS_SCHEDULER", line 288
ORA-06512: at line 1
This sounds like a proper error message. A bit less obvious is the drop_job message
SQL> exec dbms_scheduler.drop_job(job_name=>null)
ORA-20001: comma-separated list invalid near
ORA-06512: at "SYS.DBMS_UTILITY", line 236
ORA-06512: at "SYS.DBMS_UTILITY", line 272
ORA-06512: at "SYS.DBMS_SCHEDULER", line 743
ORA-06512: at line 1
comma-separated list invalid near what?
Ok, why would you create an empty job? Obviously you wouldn’t. But remember job_name could be a very long expression that won’t fit in your VARCHAR2(30) variable.
SQL> begin
dbms_scheduler.create_job(job_name=>
' "SCOTT" '||
' . '||
' "JOB10000000000000000000001" ',
job_type=>'PLSQL_BLOCK',
job_action=>'BEGIN NULL; END;');
end;
/
PL/SQL procedure successfully completed.
SQL> exec dbms_scheduler.drop_job('scott.job10000000000000000000001')
PL/SQL procedure successfully completed.
If you use drop job in the exception clause without catching the exception of the exception, it could lead to this ORA-20001 if job name is null
For exception handling, we could improve
BEGIN
CREATE JOB
RUN JOB
DROP JOB
EXCEPTION
WHEN OTHERS THEN
DROP JOB
output message
RAISE
END
into
BEGIN
CREATE JOB
RUN JOB
DROP JOB
EXCEPTION
WHEN OTHERS THEN
BEGIN
DROP JOB
EXCEPTION
WHEN IS_RUNNING
sleep
WHEN OTHERS
output message
END LOOP
output message
RAISE
END