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Chris Saxon

Thanks for the question.

Asked: September 11, 2020 - 1:36 pm UTC

Last updated: September 14, 2023 - 1:01 pm UTC


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Could you please have a look at below table structure

drop table child purge

drop table parent purge

create table parent (id number(11,0)
                    ,dt date
                    ,constraint pk_parent primary key (id)
partition by range (dt) 
partition pytr_hist_p_jan_2018  values less than (to_date(' 2018-02-01 00:00:00', 'syyyy-mm-dd hh24:mi:ss', 'nls_calendar=gregorian')),
partition "pytr_hist_p_feb_2018"  values less than (to_date(' 2018-03-01 00:00:00', 'syyyy-mm-dd hh24:mi:ss', 'nls_calendar=gregorian')),
partition "pytr_hist_p_maxvalue"  values less than (maxvalue)

create table child (id number(11,0)
                    ,name varchar2(20 char)
                    ,constraint pk_child primary key (id)
                    ,constraint fk_parent_id foreign key (id) references parent (id)
partition by reference (fk_parent_id)

I need to separate out child table from referenced partitioned and make it as independent table.
I tried dropping the constraint, but due to reference-partition it not getting completed.
alter table child drop constraint fk_parent_id

Getting error as
ORA-14650: operation not supported for reference-partitioned tables
14650. 00000 -  "operation not supported for reference-partitioned tables"

On production environment, child table size if around 40 GB, so could you please suggest any alternative how can I detach child table from parent.

and Chris said...

You can't drop the foreign key used by reference partitioning.

If you want to remove partitioning, you'll have to re-create the table. Sadly you can't use dbms_redefinition to do this:

exec dbms_redefinition.can_redef_table ( user, 'CHILD' );

ORA-23549: table "CHRIS"."CHILD" involved in reference partitioning

I'd start by trying create-table-as-select:

create table child_new as 
  select * from child;

Copy the constraints, indexes, etc. from the old table to the new, then switch them over.

You'll likely have to take an outage to do this.


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Is it possible to do the same in Oracle 19c?

A reader, September 13, 2023 - 3:29 pm UTC

Is it possible separate out child table from referenced partitioned and make it as independent table in oracle 19c version?
Chris Saxon
September 14, 2023 - 1:01 pm UTC

I'm unsure what you're trying to do here - please clarify.

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