How to use the find command on Unix/Linux systems

Here is how to list the regular files (indicated by -type f) files generated the last 30 minutes in a particular directory on a Linux/Unix server:

find . -mmin -30 -type f -exec ls -l {} +

Another example, listing files in my audit_file_dest older than 10 days:

find /u01/admin/proddb01/adump/ -name '*.aud' -mtime +10 -exec ls -latrh {} \;

Count all files with extension ".trm" generated one day or less ago:

find . -name '*.trm' -mtime -1 -type f -exec ls -l {} + | wc -l

Count all files with extension ".trm" generated more than 30 days ago:

find . -name '*.trm' -mtime +30 -type f -exec ls -l {} + | wc -l

Find all files with timestamp new than April 15th, 16:14 in the afternoon:

export TIMENOW=`date +"%a %b %e %H:%M"`
echo $TIMENOW
Thu Apr 15 16:14
find . -type f -newermt "$TIMENOW" -exec ls -la {} \;

Find and delete can be done in different ways, the recommended way is to use the -delete option. In the command below, I want to find and delete all *.trc and *.trm files older than 10 days:

find /u01/oracle/diag/rdbms/mydb/mydb/trace -type f -name 'mydb*.tr*' -mtime +10 -delete

Delete all *.trm files in the current directory generated earlier than 24 hrs ago:

find *.trm -mmin +1440 -type f -delete

If the -delete option is not available, you can use a different method:

find /u01/oracle/diag/rdbms/mydb/mydb/trace -type f -name 'mydb*.tr*' -mtime +10 -exec rm -f {} \;

Or, using xargs, finding files older than 2 days:

find /u01/oracle/diag/rdbms/mydb/mydb/trace -type f -name 'mydb*.tr*' -mtime +2 -print0 | xargs -I {} -0 rm -v "{}"

Pipe to wc to get the number of files deleted:

find /u01/oracle/diag/rdbms/mydb/mydb/trace -type f -name 'mydb*.tr*' -mtime +2 -print0 | xargs -I {} -0 rm -v "{}" | wc -l

Some good external sources:

How To Format Date For Display or Use In a Shell Script
Linux / Unix: Find And Remove Files With One Command On Fly
Linux Find Command with Practical Examples

How to to use the script-command to log everything a script does

The utility "script" will make a typescript of a terminal session.
Very useful if you have a script which produces lots of output, and you need to search for errors after the script has run to completion:

script -c /tmp/install_oracle.sh

Unless you add the name of the output file, the resulting file will be called typescript.

How to monitor rollback activity after killing long-running session

Found this brilliant script here: http://www.oracle-wiki.net/startsqlshowrollinfo

prompt This query will monitor rollbacks of transactions after killing a job or session. 
prompt If the used undo records/used undo blocks count is going down, then the transaction is rolling back. 
prompt If they are going up, then the transaction is still running.
SET PAUSE ON
SET PAUSE 'Press Return to Continue'
SET PAGESIZE 60
SET LINESIZE 300
 
COLUMN username FORMAT A20
COLUMN sid FORMAT 9999
COLUMN serial# FORMAT 99999
 
SELECT s.username,
       s.sid,
       s.serial#,
       t.used_ublk,
       t.used_urec,
       rs.segment_name,
       r.rssize,
       r.status
FROM   v$transaction t,
       v$session s,
       v$rollstat r,
       dba_rollback_segs rs
WHERE  s.saddr = t.ses_addr
AND    t.xidusn = r.usn
AND   rs.segment_id = t.xidusn
ORDER BY t.used_ublk DESC
/

In my environment, the output looked as follows:

This query will monitor rollbacks of transactions after killing a job or session.
If the used undo records/used undo blocks count is going down, then the transaction is rolling back.
If they are going up, then the transaction is still running.

USERNAME               SID SERIAL#  USED_UBLK  USED_UREC SEGMENT_NAME                       RSSIZE STATUS         
-------------------- ----- ------- ---------- ---------- ------------------------------ ---------- ---------------
MYUSERNAME_XX_XXX_  1194   10616     670875   14088690 _SYSSMU22_1415974968$          1189502976 ONLINE

The USED_UBLK was dropping, so the ongoing rollback could be confirmed to the users.

How to delete a specific line from a file, or all characters following a specific character using sed

If you want to search a file for a particular string, and then delete that line, use sed, like this:

sed -i "/_use_column_stats_for_function/d" init.ora

In bash, using the double quotation marks was the only way to make this work when using a variable instead of a fixed string.

To delete a specific line number, in this case line number 7:

 sed -i '7d' myfile.txt
 

To delete lines 7 and 8:

 sed -i '7,8d' insert_data.sql

To delete everything after a specific character, for example #:

sed -i "s/#.*//g" /tmp/autoupgrade.ora

How to find the currently enabled unified auditing policies in an Oracle 12c database

Oracle 12c comes with two auditing policies enabled by default: ORA_SECURECONFIG and ORA_LOGON_FAILURES.
You can find the currently enabled policies in the AUDIT_UNIFIED_ENABLED_POLICIES view.

The query below will reveal what the currently enabled policies will actually audit

select policy_name,audit_option,condition_eval_opt
from audit_unified_policies
where policy_name in (  select policy_name 
                        from audit_unified_enabled_policies);
                        

The result shows that the default Unfied Auditing Setup covers many of the actions you would certainly want to audit, like DROP USER, ALTER SYSTEM etc:

POLICY_NAME	AUDIT_OPTION	CONDITION_EVAL_OPT
ORA_SECURECONFIG	LOGMINING	NONE
ORA_SECURECONFIG	TRANSLATE ANY SQL	NONE
ORA_SECURECONFIG	EXEMPT REDACTION POLICY	NONE
ORA_SECURECONFIG	PURGE DBA_RECYCLEBIN	NONE
ORA_SECURECONFIG	ADMINISTER KEY MANAGEMENT	NONE
ORA_SECURECONFIG	DROP ANY SQL TRANSLATION PROFILE	NONE
ORA_SECURECONFIG	ALTER ANY SQL TRANSLATION PROFILE	NONE
ORA_SECURECONFIG	CREATE ANY SQL TRANSLATION PROFILE	NONE
ORA_SECURECONFIG	CREATE SQL TRANSLATION PROFILE	NONE
ORA_SECURECONFIG	CREATE EXTERNAL JOB	NONE
ORA_SECURECONFIG	CREATE ANY JOB	NONE
ORA_SECURECONFIG	GRANT ANY OBJECT PRIVILEGE	NONE
ORA_SECURECONFIG	EXEMPT ACCESS POLICY	NONE
ORA_SECURECONFIG	CREATE ANY LIBRARY	NONE
ORA_SECURECONFIG	GRANT ANY PRIVILEGE	NONE
ORA_SECURECONFIG	DROP ANY PROCEDURE	NONE
ORA_SECURECONFIG	ALTER ANY PROCEDURE	NONE
ORA_SECURECONFIG	CREATE ANY PROCEDURE	NONE
ORA_SECURECONFIG	ALTER DATABASE	NONE
ORA_SECURECONFIG	GRANT ANY ROLE	NONE
ORA_SECURECONFIG	DROP PUBLIC SYNONYM	NONE
ORA_SECURECONFIG	CREATE PUBLIC SYNONYM	NONE
ORA_SECURECONFIG	DROP ANY TABLE	NONE
ORA_SECURECONFIG	ALTER ANY TABLE	NONE
ORA_SECURECONFIG	CREATE ANY TABLE	NONE
ORA_SECURECONFIG	DROP USER	NONE
ORA_SECURECONFIG	CREATE USER	NONE
ORA_SECURECONFIG	AUDIT SYSTEM	NONE
ORA_SECURECONFIG	ALTER SYSTEM	NONE
ORA_LOGON_FAILURES	LOGON	NONE
ORA_SECURECONFIG	CREATE DATABASE LINK	NONE
ORA_SECURECONFIG	DROP DATABASE LINK	NONE
ORA_SECURECONFIG	ALTER USER	NONE
ORA_SECURECONFIG	CREATE ROLE	NONE
ORA_SECURECONFIG	DROP ROLE	NONE
ORA_SECURECONFIG	SET ROLE	NONE
ORA_SECURECONFIG	CREATE PROFILE	NONE
ORA_SECURECONFIG	DROP PROFILE	NONE
ORA_SECURECONFIG	ALTER PROFILE	NONE
ORA_SECURECONFIG	ALTER ROLE	NONE
ORA_SECURECONFIG	CREATE DIRECTORY	NONE
ORA_SECURECONFIG	DROP DIRECTORY	NONE
ORA_SECURECONFIG	ALTER DATABASE LINK	NONE
ORA_SECURECONFIG	CREATE PLUGGABLE DATABASE	NONE
ORA_SECURECONFIG	ALTER PLUGGABLE DATABASE	NONE
ORA_SECURECONFIG	DROP PLUGGABLE DATABASE	NONE
ORA_SECURECONFIG	EXECUTE	NONE

If the $ORACLE_HOME/rdbms/admin/secconf.sql script was created during database creation, you will have some other policies in your database, too, but they won't be enabled by default. These can be found by executing the following statement:

select policy_name,count(audit_option) "number of audits"
from AUDIT_UNIFIED_POLICIES
where policy_name not in (select unique policy_name from audit_unified_enabled_policies )
group by policy_name
order by 2 desc;

In my database, the following collection shows up as being created, but not yet enabled:

POLICY_NAME	number of audits
ORA_RAS_POLICY_MGMT	33
ORA_CIS_RECOMMENDATIONS	26
ORA_RAS_SESSION_MGMT	14
ORA_ACCOUNT_MGMT	9
ORA_DATABASE_PARAMETER	3

How to use the dbms_explan.display_cursor function to find the execution plan of a query in the Cursor Cache

set linesize 200
set pagesize 0
select * from table
(dbms_xplan.display_cursor( '0syc4upspr638',3,'TYPICAL'));
exit

Where
- the first argument is the SQL id
- the second argument cursor child number
- the third argument is the format string. TYPICAL is the default value.


See the Oracle Documentation for more information on how to use dbms_xplan

How to migrate a non-CDB database to a PDB on the same host

There are many ways to migrate your non-cdb Oracle databases to the new Multitenant Architecture. Here I will show you how to clone a non-cdb database to a PDB running in a container database

Asumptions:
You have two Oracle databases of version 12.1 or higher running on the same server:

1. Your original, non-cdb database called db01
2. Your new container database called cdb01
Both of these databases are running out of Oracle Home installe in /u01/oracle/product/12c

Step 1: For Oracle 12.1, open your non-CDB in read only mode (not needed from version 12.2 and onwards):

shutdown immedate
startup mount
alter database open read only;

Step 2: create an xml file that describes the non-CDB database using the package dbms_pdb:

export ORACLE_SID=db01
sqlplus / as sysdba

Generate the file:

set serveroutput on
begin
  dbms_pdb.describe( pdb_descr_file => '/tmp/ncdb.xml');
end;
/

Step 3: Create the pluggable database

Connect to your CDB, and create the PDB using the script you created in step 2.

export ORACLE_SID=cdb01
sqlplus / as sysdba

create pluggable database pdb01
using '/tmp/ncdb.xml'
copy
file_name_convert = ('/u02/oradata/db01/', '/u02/oradata/cdb01/PDBS/pdb01/');

Note that I am choosing to copy the files from the original location of the non-CDB database, to a brand new one, using the directive file_name_convert. There are other options, too: MOVE and NOCOPY

Step 4: execute $ORACLE_HOME/rdbms/admin/noncdb_to_pdb.sql

sqlplus / as sysdba
alter session set container=PDB01;
@?/rdbms/admin/noncdb_to_pdb.sql

I did receive errors during this phase:

ORA-65172: cannot run noncdb_to_pdb.sql unless pluggable database is an
unconverted non-container database
ORA-06512: at "SYS.DBMS_PDB", line 154
ORA-06512: at line 1

The error message seemed to be harmless:

oracle@myserver.mydomain.com:[cdb1]# oerr ora 65172
65172, 00000, "cannot run noncdb_to_pdb.sql unless pluggable database is an unconverted non-container database"
// *Cause:  An attempt was made to run 'noncdb_to_pdb.sql' on a pluggable
//          database (PDB) that was not an unconverted non-container database.
// *Action: 'noncdb_to_pdb.sql' is not necessary for this PDB.
//

Further research showed 1) the Pdb was indeed created, and 2) that there were errors in PDB_PLUG_IN_VIOLATIONS:

select PDB_ID,PDB_NAME,STATUS,CON_ID from cdb_pdbs

    PDB_ID PDB_NAME                       STATUS                          CON_ID
---------- ------------------------------ --------------------------- ----------
         2 PDB01                          NEW                                  2

alter session set container=cdb$root;


SELECT TO_CHAR(TIME,'dd.mm.yyyy hh24:mi') "time",NAME,STATUS,MESSAGE 
FROM PDB_PLUG_IN_VIOLATIONS;

Result:

time	NAME	STATUS	MESSAGE
20.09.2017 14:17	PDB01	PENDING	Database option CATJAVA mismatch: PDB installed version 12.1.0.2.0. CDB installed version NULL.
20.09.2017 14:17	PDB01	PENDING	Database option CONTEXT mismatch: PDB installed version 12.1.0.2.0. CDB installed version NULL.
20.09.2017 14:17	PDB01	PENDING	Database option JAVAVM mismatch: PDB installed version 12.1.0.2.0. CDB installed version NULL.
20.09.2017 14:17	PDB01	PENDING	Database option ORDIM mismatch: PDB installed version 12.1.0.2.0. CDB installed version NULL.
20.09.2017 14:17	PDB01	PENDING	Database option XML mismatch: PDB installed version 12.1.0.2.0. CDB installed version NULL.
20.09.2017 14:17	PDB01	PENDING	Sync PDB failed with ORA-65177 during 'alter user sys identified by *'
20.09.2017 14:17	PDB01	PENDING	Sync PDB failed with ORA-65177 during 'alter user system identified by *'

A quick search on Oracles support site revealed that these errors can be ignored. See Doc ID 2020172.1 "OPTION WARNING Database option mismatch: PDB installed version NULL" in PDB_PLUG_IN_VIOLATIONS"

Finally, remember to open your pdb in read write mode. It was in MIGRATE mode after the noncdb_to_pdb.sql script had been run and failed:

 select con_id,name,open_mode from v$containers;

    CON_ID NAME      OPEN_MODE
---------- --------- -----------------------------
         1 CDB$ROOT  READ WRITE
         2 PDB01     MIGRATE

alter session set container=PDB01;

alter pluggable database close;

Pluggable database altered.

alter pluggable database open;

 select con_id,name,open_mode from v$containers;

    CON_ID NAME      OPEN_MODE
---------- --------- -----------------------------
         2 PDB01     READ WRITE