Author: Laurent Schneider

ANNOUNCEMENT: 12cR2 documentation is available

The doc docs.oracle.com/database/122 is available. Check new features and stay tuned. Okay, just 12 for today : HIGH compressed index, case insensitive database with bound collation, partitioned external tables, AL32UTF8 default for new database, listagg overflow, VALIDATE_CONVERSION, approx_percentile, json_exists, flashback pluggable database, the SHARING clause, RAC streched clusters site definition and INACTIVE_ACCOUNT_TIME in profile. Some […]

To shrink or to move

If you delete most of the rows in one table, you probably want to regain that space, to minimize IO and fragmentation. If you delete most of the rows in most of the tables, you probably also want to resize the datafile to reduce storage and backup space. In this case, you could move your […]

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 […]

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 […]

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 […]

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. 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 […]

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 […]

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 […]

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; […]

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 […]

Open last one-note page

If you got a one-note document, you may want to automatically go to the last page. This is possible with powershell. First you create a ComObject. There are incredibly many ComObject that could be manipulated in powershell. $o = New-Object -ComObject OneNote.Application Now it get’s a bit confusing. First you open your document [ref]$x = […]

Don’t call it test

There are quite a few names to avoid in your scripts. Even if there are not reserved-words, keep away ! I’ll start with test cd $HOME/bin vi test echo hello world chmod +x test ./test hello world The problem is that it may break your other scripts $ ssh localhost test 1 = 2 && […]

list database monitoring users

I am quite familiar with the SYSMAN tables but this one required me some googling beyond the Oracle documentation. The list of targets in your Oracle Enterprise Manager is in SYSMAN.MGMT_TARGETS. Each database target is monitored by a database user, typically DBSNMP. To retrieve this information, you need some to hijack your database, read this […]

Drop table if exists

The syntax that you are looking for is docs.oracle.com/…/drop-table.html DROP [TEMPORARY] TABLE [IF EXISTS] tbl_name [, tbl_name] … [RESTRICT | CASCADE] Wait, this does not work ! SQL> drop table if exists t; drop table if exists t * ERROR at line 1: ORA-00933: SQL command not properly ended Okay. It was the Oracle MySQL […]

Irrecoverable part III : a fix

After part I:the problem, Part II: two reports here is part III. We have backed up archivelog during a full and deleted them before the full completed. RMAN> list backup of archivelog all; List of Backup Sets =================== BS Size Type Elapsed Completion — —— —- ——– ———- 15 4.00K DISK 00:00:00 13:31:08 BP Key: […]

Irrecoverable full backup part II : reporting

After my post Can you restore from a full online backup ?, I needed to come up with a report. Assuming that each backup goes in a different directory, I just wrote two reports. Report gaps in v$backup_redolog (or rc_backup_redolog if you use the catalog) DIR FIRST_CHANGE# NEXT_CHANGE# ——- ————- ———— /bck01/ 284891 285140 /bck01/ […]

Can you restore from a full online backup ?

The question is not HOW TO DO IT but WHETHER YOU CAN DO IT ! A typical backup script would contains something like BACKUP DATABASE PLUS ARCHIVELOG: backup database format ‘/u99/backup/DB01/20150518/full_0_%d_s%s_p%p’ plus archivelog format ‘/u99/backup/DB01/20150518/arc_%d_s%s_p%p’; Starting backup at 2015-05-18_18:27:55 current log archived input archived log thread=1 sequence=469 … piece handle= /u99/backup/DB01/20150518/arc_DB01_s86_p1 Finished backup at 2015-05-18_18:27:58 […]

🎂 10 years 🎂

Thanks to all my readers for being so faithful 🙂 I’ll post a new solution to calculate factorial. This is the one I posted 10 years ago : https://laurentschneider.com/2005/05/recursive-sql.html I also used it in the obfuscation contest with function f (x number) return number is begin return case x when 1 then x else x*f(x-1) […]

run sudo, ssh, password, su in simulated interactive mode

Some commands do not like non-interactive mode $ passwd newpassword > newpassword > EOF Changing password for user lsc. Current password for lsc@example.com: passwd: Authentication token manipulation error $ echo oraclepassword | su – oracle standard in must be a tty $ echo sudopassword | sudo su – oracle [sudo] password for lsc: sudo: sorry, […]

bypass ora-20

When you really need to run one script, at all cost, an annoying error is ORA-00020: maximum number of processes (40) exceeded, which can even occurs as sysdba. Test case (21 is a not something to do in real life): SQL> alter system set processes=21 scope=spfile; System altered. SQL> startup force quiet ORACLE instance started. […]

switch user in Oracle

Almost a decade ago I wrote about su in sqlplus. This 10gR2 “new” feature allows delegation à la sudo. By checking the DBA_USERS in 12c I found PROXY_ONLY_CONNECT. According to Miguel Anjo, there is a secret syntax for allowing only the proxy user. SQL> ALTER USER app_user PROXY ONLY CONNECT; SQL> CONNECT app_user/xyz ERROR:ORA-28058: login […]