My Oracle Support Banner

Parallel DML/DDL using sequence produces wrong results (Doc ID 1528656.1)

Last updated on MARCH 27, 2014

Applies to:

Oracle Database - Enterprise Edition - Version and later
Information in this document applies to any platform.


If dml or ddl with sequence is run in parallel,it produces wrong results.


drop table tab;
drop sequence sq;
drop type vtype;

create table tab (c1 number, c2 number);

insert into tab values(1, 2);
insert into tab values(2, 2);


alter table tab parallel 2;
alter session force parallel query parallel 1;
alter session force parallel dml parallel 2;

create table tab2 as select * from tab;

create or replace view v as
select /*+ no_parallel(tab 2) no_parallel(tab2 2) */ t2.c2
from tab t1, tab2 t2 where t1.c1 = t2.c1;
create unique index i2 on tab2(c1);

explain plan into xpl_table for
update v set c2 = sq.nextval;

execute display_plan(slave_sql=>true, clean=>true);

update v set c2 = sq.nextval;


To view full details, sign in with your My Oracle Support account.

Don't have a My Oracle Support account? Click to get started!

In this Document

This document is being delivered to you via Oracle Support's Rapid Visibility (RaV) process and therefore has not been subject to an independent technical review.
My Oracle Support provides customers with access to over a million knowledge articles and a vibrant support community of peers and Oracle experts.