ORA-00439 feature not enabled Deferred Segment Creation 11g enterprise to standard edition downgrade

1293326.1


http://lifeandoracle.blogspot.in/2012/07/ora-00439-feature-not-enabled-deferred.html
http://ocpdba.wordpress.com/2009/10/09/deferred-segment-creation-segmentless-tables-11gr2-new-feature-and-dumb-questions/
http://asanga-pradeep.blogspot.in/2011/01/segment-creation-behavior-change.html
http://www.donotcommit.net/?p=51


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1. Init.ora Parameter "DEFERRED_SEGMENT_CREATION" Reference Note [ID 1216282.1]
2. IMP-00003, ORA-00959 While Importing Data Into Existing Table Of 11gR2 Using Traditional Import [ID 1180873.1]
3. Bug 8795792 - DBMS_METADATA.get_ddl generates wrong keywords for compressed indexes in 11.2 [ID 8795792.8]
4. Exporting Schema In 11.2 Database With 10g Client Gives ORA-1455 [ID 1083330.1]
1293326.1
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then you must know you have just hit one of the new features of 11gR2. Unfortunately this feature makes the life of the casual DBA a little bit more complicated than necessary.

I found an interesting debate about whether this must be considered a feature or a bug in the OTN forums but I very much appreciated the last comment where Michiel provided a working solution without delving into philosophical matters. I remember doing the same thing when dealing with another EXPDP/IMPDP problem between versions 11.1.0.6 and 11.1.0.7.

---------------------------Solution 1--------------

-- on the source instance
EXPDP ldbo/ldbo@apx1314srv full=Y dumpfile=expdp1314.dmp directory=DATA_DUMP_DIR logfile=expdp1314.log version=10.2

-- on the target instance
IMPDP ldbo/ldbo@apx1314srv full=Y dumpfile=expdp1314.dmp directory=DATA_DUMP_DIR logfile=expdp1314.log version=10.2


---------------------------Solution 2--------------

For 11.2.0.1 one way to avoid the issue is to allocate segment manually before the export. This could be done with

alter table  allocate extent;

select 'alter table '||table_name||' allocate extent;' from user_tables where segment_created = 'NO';



set autocommit on;
set line 124;

select 'ALTER TABLE ' || TABLE_NAME || ' ALLOCATE EXTENT;' from user_tables where SEGMENT_CREATED = 'NO';
select 'ALTER TABLE '|| TABLE_NAME || ' ALLOCATE EXTENT;' from user_lobs where SEGMENT_CREATED = 'NO';
select 'ALTER INDEX '|| INDEX_NAME || ' ALLOCATE EXTENT;' from user_indexes where SEGMENT_CREATED = 'NO';



---------------Solution 3--------

SQL> alter system set deferred_segment_creation=false;



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From 11g Release 2 all tables created without rows, do not create any segments (by default). If you want to change this behaviour, tweak the spfile parameter “deferred_segment_creation” to FALSE. Anyway the people installing Peoplesoft, SAP, Siebel and other thousand-table data models, really do thank for this new feature.

How does it work?

If the INITIAL extent of a table is 15 MegaBytes in size, but the table is empty, the table won’t ask for that 15 MB of space. As soon as the first row of data is inserted (even a few bytes), the Oracle space engine will run the storage space settings of the table, before inserting that line, making the table actually owner of that space. You can create a 100GB table onto a 100MB tablespace as long as the table is empty, because the space will only be reclaimed by the table when it receives the first row.

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In 11.2 the initialization parameter DEFERRED_SEGMENT_CREATION controls whether segment space is allocated at the time of the segment creation. This is set to true by default both on enterprise edition and standard edition. But on standard edition this parameter has no effect as this feature is not enabled. Initialization parameter behavior could be override at table with
SQL> CREATE TABLE x(a number) SEGMENT CREATION IMMEDIATE;
or
SQL> CREATE TABLE x(a number) SEGMENT CREATION DEFERRED;
But on standard edition this would still give an error.
SQL>  CREATE TABLE x(a number) SEGMENT CREATION DEFERRED;
CREATE TABLE x(a number) SEGMENT CREATION DEFERRED
*
ERROR at line 1:
ORA-00439: feature not enabled: Deferred Segment Creation
Problem happens when exporting some empty tables from an enterprise edition database to a standard edition database. According to the default behavior on enterprise edition when tables have no rows there won't be any segments. But default behavior on standard edition is that, tables are always created with segments.

In 11.2.0.1 when importing tables from enterprise to standard edition tables with no segments throws an error while in 11.2.0.2 tables get created with segments without an error.


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