create table进阶学习系列(八)
继续学习create table table_properties子句

语法:
SQL> select cache from user_tables where table_name='T_PROP';

CACHE
----------------------------------------
N

SQL> drop table t_prop purge;

Table dropped.

SQL> create table t_prop(a int) cache;

Table created.

SQL> select cache from user_tables where table_name='T_PROP';

CACHE
----------------------------------------
Y

----parallel选项的值=cpu个数*parallel_thread_per_cpu,一般不用配置此值,由oracle自动计算得到
PARALLEL Specify PARALLEL if you want Oracle to select a degree of parallelism equal to the number of CPUs
available on all participating instances times the value of the PARALLEL_THREADS_PER_CPU initialization parameter.

SQL> create table t_prop(a int);

Table created.

SQL> select degree from user_tables where table_name='T_PROP';

DEGREE
----------------------------------------------------------------

1

SQL> drop table t_prop purge;

Table dropped.

SQL> create table t_prop(a int) parallel 3;

Table created.

SQL> select degree from user_tables where table_name='T_PROP';

DEGREE
----------------------------------------------------------------

3

SQL> create table t_prop(a int);

Table created.

SQL> select dependencies from user_tables where table_name='T_PROP';

DEPENDENCIES
----------------
DISABLED

SQL> drop table t_prop purge;

Table dropped.

---rowdependences用于高级复制环境,increases the size of each row by 6 bytes
SQL> create table t_prop(a int) rowdependencies;

Table created.

SQL> select dependencies from user_tables where table_name='T_PROP';

DEPENDENCIES
----------------
ENABLED

语义:

测试:

后记:

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create table进阶学习系列(八)

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