Oracle Parallel __oracle

Parallel DDL

Sql> CREATE index idx_t3 on T1 (object_name,object_id) parallel;


The index has been created.


Sql> Select Index_name, degree from user_indexes where index_name= ' idx_t3 ';


No rows selected


Sql> Select Index_name, degree from user_indexes where index_name= ' idx_t3 ';


Index_name DEGREE
------------------------------------------------------------ ------------------------------------
Idx_t3 DEFAULT


sql> alter index IDX_T3 Noparallel;


The index has changed.


Sql> Select Index_name, degree from user_indexes where index_name= ' idx_t3 ';


Index_name DEGREE
------------------------------------------------------------ ------------------------------------
IDX_T3 1

See the parallelism of DDL statements after execution, the related objects have the degree of parallelism, so after the DDL is executed, it is best to reset the degree of parallelism of the object.

Parallel DML

Using parallel in SQL may not actually go in parallel, resulting in a longer time to take, and to use real parallelism

1alter session force parallel DML;

2alter sessoin enable parallel dml;+ parallel hint