How to solve OUI-10197:Unable to create a new Oracle Home during cloning

Short background:

After a failed attempt to clone an Oracle 12c installation, using Oracle's perl script clone.pl, like this:

oracle@myserver:[DBSID]# cd /u01/oracle/product/12102/clone/bin
oracle@myserver:[DBSID]# perl clone.pl ORACLE_HOME=/u01/oracle/product/12102 ORACLE_HOME_NAME=12102 ORACLE_BASE=/u01/oracle OSDBA_GROUP=dba

the following error was thrown:

OUI-10197:Unable to create a new Oracle Home at /u01/oracle/product/12102. Oracle Home already exists at this location. Select another location.
SEVERE:OUI-10197:Unable to create a new Oracle Home at /u01/oracle/product/12102. Oracle Home already exists at this location. Select another location.

The solution is to detach the Oracle Home from the Inventory:

oracle@myserver:[DBSID]# ./runInstaller -detachHome ORACLE_HOME=/u01/oracle/product/12102 invPtrLoc=/u01/oracle/product/12102/oraInst.loc
Starting Oracle Universal Installer...

Checking swap space: must be greater than 500 MB.   Actual 7814 MB    Passed
The inventory pointer is located at /etc/oraInst.loc
'DetachHome' was successful.

You can now rerun clone.pl.
Note that you do not need to physically remove files from disk and unzip new ones, since your Inventory is now unaware of the previously failed installation attempt.

Simply run your clone again. Log output below.

Starting Oracle Universal Installer...

Checking Temp space: must be greater than 500 MB.   Actual 1810 MB    Passed
Checking swap space: must be greater than 500 MB.   Actual 7814 MB    Passed
Preparing to launch Oracle Universal Installer from /tmp/OraInstall2017-09-07_09-28-15AM. Please wait ...You can find the log of this install session at:
 /home/oracle/oraInventory/logs/cloneActions2017-09-07_09-28-15AM.log
..................................................   5% Done.
..................................................   10% Done.
..................................................   15% Done.
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..................................................   45% Done.
..................................................   50% Done.
..................................................   55% Done.
..................................................   60% Done.
..................................................   65% Done.
..................................................   70% Done.
..................................................   75% Done.
..................................................   80% Done.
..................................................   85% Done.
..........
Copy files in progress.

Copy files successful.

Link binaries in progress.

Link binaries successful.

Setup files in progress.

Setup files successful.

Setup Inventory in progress.

Setup Inventory successful.

Finish Setup successful.
The cloning of 12102 was successful.
Please check '/home/oracle/oraInventory/logs/cloneActions2017-09-07_09-28-15AM.log' for more details.
Setup Oracle Base in progress.
Setup Oracle Base successful.
..................................................   95% Done.
As a root user, execute the following script(s):
        1. /u01/oracle/product/12102/root.sh
..................................................   100% Done.

How to open and close a pluggable database in 12c multitenant database

Connect to the container database:

sqlplus sys@cdbveg as sysdba

SQL*Plus: Release 12.1.0.1.0 Production on Wed Sep 6 13:22:57 2017

Copyright (c) 1982, 2013, Oracle. All rights reserved.

Enter password:

Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options

SQL> show con_name

CON_NAME
------------------------------
CDB$ROOT
SQL>

Check status:

select con_id, dbid, name,open_mode from v$containers;

CON_ID	DBID	NAME	OPEN_MODE
1	3465911448	CDB$ROOT	READ WRITE
2	374976711	PDB$SEED	READ ONLY
3	53565692	PDBVEG1	MOUNTED

Open the pluggable database;

alter pluggable database pdbveg1 open;

Check status again:

CON_ID	DBID	NAME	OPEN_MODE
1	3465911448	CDB$ROOT	READ WRITE
2	374976711	PDB$SEED	READ ONLY
3	53565692	PDBVEG1	READ WRITE

To close the PDB and bring it back to a mounted state:

alter pluggable database pdbveg1 close;

Solution for ORA-01442: column to be modified to NOT NULL is already NOT NULL during online redefinition

When trying to execute dbms_redefinition.copy_table_dependents, like this:

whenever sqlerror exit
set serveroutput on
set feedback off
set verify   off
set timing on

DECLARE
l_num_errors PLS_INTEGER;
BEGIN
DBMS_REDEFINITION.COPY_TABLE_DEPENDENTS(uname=>'USER1',
orig_table=>'DOCUMENTS',
int_table=>'DOCUMENTS_INTERIM',
copy_indexes=>0,
copy_triggers=>TRUE,
copy_constraints=>TRUE,
copy_privileges=>TRUE,
ignore_errors=>FALSE,
num_errors => l_num_errors,
copy_statistics=>TRUE,
copy_mvlog=>TRUE);
DBMS_OUTPUT.put_line('l_num_errors=' || l_num_errors);
END;
/

You get the following error:

ORA-01442: column to be modified to NOT NULL is already NOT NULL
ORA-06512: at "SYS.DBMS_REDEFINITION", line 1646

Cause:
Your interim table has NOT NULL constraints. This is easy to overlook, particulary if you create your interim table using CTAS ("Create Table As Select") statement.
Your interim table should not have any constraints before you execute the copy_table_dependents procedure.

Solution:
Drop the NOT NULL constraint, and retry the operation:

SQL> alter table user1.documents_interim drop constraint SYS_C0018782;

Table altered.

Note that you do not have to abort the redefinion procedure at this point, and start all over again.

Simply drop the constraint, and retry your operation.

A workaround for ORA-12008 and ORA-14400 during online redefinition

To introduce partitions in one of my tables, I was using online redefinition of a rather large table.
The following error was thrown after about 30 minutes after having started the redefinition with dbms_redefintion.start_redef:

begin
*
ERROR at line 1:
ORA-12008: error in materialized view refresh path
ORA-12801: error signaled in parallel query server P004
ORA-14400: inserted partition key does not map to any partition
ORA-06512: at "SYS.DBMS_REDEFINITION", line 75
ORA-06512: at "SYS.DBMS_REDEFINITION", line 3459
ORA-06512: at line 2

It turned out that there were NULL values in the column that would be the future partition key.
Everything was explained very well in Doc ID 2103273.1 "ORA-14400: inserted partition key does not map to any partition, with possible ORA-12008: error in materialized view refresh path".

You can solve this in two ways:

a) find the rows with null values, and update them

or

b) use an overflow partition which will work as a "catch all" basket for rows that can't be mapped to a specific partition. NULL values sort in this category.

Since I was using interval range partitioning, I had to choose the former of the two options. If this is not possible, you can't use interval partitioning, and need to explicitly define every partition + your overflow partition in your interim table.

How to explain a SQL statement using bind variables

Sometimes I am asked to analyze an SQL statement picked up from Enterprise Manager Cloud Control.
These SQL statements only reveal the bind variables used, and not their actual values.

To get a more realistic explain plan, ask your developers to provide you with the actual literal values used in the SQL statement, and then prepare a script that contains the following:

connect username/password
SET TIMING ON
SET LINESIZE 200
SET PAGESIZE 0

var b9 number;
var b8 number;
var b7 number;
var b6 varchar2(3);
var b5 varchar2(3);
var b4 varchar2(4);
var b3 varchar2(1);
var b2 varchar2(2);
var b1 varchar2(2);

exec :B9 := 12345;
exec :B8 := 6127737;
exec :B7 := 2013;
exec :B6 := 'KOC';
exec :B5 := 'PPQ';
exec :B4 := 'OOPQ';
exec :B3 := '7';
exec :B2 := 'YM';
exec :B1 := 'WT';

EXPLAIN PLAN FOR
  SELECT ...
  FROM ...
  WHERE COL1 NOT IN (:B6, :B5, :B4)
  AND COL2 = :8
  AND COL3 = :9;


SELECT * FROM table(DBMS_XPLAN.DISPLAY);

Run the script using sqlplus.

Such a script can also come in handy if you're asked to perform changes to the tables' structure, and then execute the actual script to see how much time it takes to execute.
In this case, remove the EXPLAIN PLAN clause and the call to DBMS_XPLAN.DISPLAY, and you'll have all you need to execute the actual SQL statements you're tuning.

How to move a partition online from Oracle 12.1 and onwards

From Oracle version 12.1 and ownwards, moving partitions and subpartitions becomes non-blocking DDL operations. DML against the table can continue while the subobject is being moved. Oracle guarantees that global indexes are maintained during the move operation, so you no longer have to specify the "UPDATE INDEXES ONLINE"-clause.

Remember that skipping this clause will trigger Asynchronous Global Index Maintenance during the nightly maintenance window.

To move a subpartition to a new tablespace:

ALTER TABLE MYUSER.MYTABLE 
MOVE SUBPARTITION P_201312 ONLINE
TABLESPACE MYTABSPC;

To compress the subpartition data at the same time, use

ALTER TABLE MYUSER.MYTABLE 
MOVE SUBPARTITION P_201312_P_OPLSUM ONLINE 
TABLESPACE MYTABSPC 
ROW STORE COMPRESS ADVANCED;

To move a partition to a new tablespace using a DOP of 4 while updating any global indexes defined on the table:

ALTER TABLE MYUSER.MYTABLE
MOVE PARTITION P_2018_05 ONLINE
TABLESPACE NEWTABLESPACE
PARALLEL 4;

To compress the partition data at the same time, use

ALTER TABLE MYUSER.MYTABLE
MOVE PARTITION P_2018_06 ONLINE
TABLESPACE NEWTABLESPACE
ROW STORE COMPRESS ADVANCED
PARALLEL 4;

Remember to change the properties for the partition and the table, too:

ALTER TABLE MYUSER.MYTABLE
MODIFY DEFAULT ATTRIBUTES FOR PARTITION P201312
TABLESPACE MYTABSPC;

ALTER TABLE MYUSER.MYTABLE 
MODIFY DEFAULT ATTRIBUTES 
TABLESPACE MYTABSPC;

A simple query to find how much space the partitions are using would be:

select partition_name,tablespace_name, round(sum(bytes)/1024/1024/1024,1) "GB"
from dba_segments
where segment_name='MYTABLE'
group by partition_name,tablespace_name
order by 1;

Example output:

PARTITION_NAME	TABLESPACE_NAME	GB
SYS_SUBP102302	DATA2	8,9
SYS_SUBP102303	DATA2	2
SYS_SUBP102304	DATA2	0
SYS_SUBP120071	DATA2	7,9
SYS_SUBP120072	DATA	1,8
SYS_SUBP120073	DATA2	0
SYS_SUBP12401	DATA	129,5

Source: Oracle Documentation, New Features list, Version 12.1.0.1. See section "2.2.3.4 ONLINE Move Partition"

What exactly is a LOB index object?

This question was answered by Tom Kyte in an old post from 2001.


A LOB is simply a pointer. It points to an index. The index points to the chunks that make up the LOB.
Hence when you create a LOB, you will always get a lob index created (to find the chunks for the LOB fast) and a segment that holds the LOB data (chunks).

and

You control the placement of the LOB segment. You have NO control over the LOB index, it is an internal structure and goes where it goes. The LOB index is considered "part of the LOB" itself.