批量導入某大張表數據的時候的最佳實踐： 1、把表上所有的索引都設置為unusable: alter index <index name> unusable; 2、做批量導入 3、rebuild索引：alter index <index name> rebuild parallel nologging;
演示如下 SQL> create table emp as select * from employees; Table created.
SQL> create index idx_emp_job on emp(job_id); Index created.
SQL> select bytes from user_segments where segment_name='IDX_EMP_JOB'; BYTES ---------- 65536
SQL> alter index idx_emp_job unusable; Index altered.
SQL> insert into emp select * from emp; 107 rows created.
SQL> / 214 rows created.
SQL> / 428 rows created.
SQL> / 856 rows created.
SQL> / 1712 rows created.
SQL> / 3424 rows created.
SQL> / 6848 rows created.
SQL> / 13696 rows created.
SQL> / 27392 rows created.
SQL> / 54784 rows created.
SQL> SQL> SQL> SQL> / 109568 rows created.
SQL> commit; Commit complete.
SQL> select bytes from user_segments where segment_name='IDX_EMP_JOB'; no rows selected
SQL> select status from user_objects where object_name='IDX_EMP_JOB'; STATUS ------- VALID
SQL> alter index IDX_EMP_JOB rebuild parallel 4 nologging; Index altered.
SQL> select bytes from user_segments where segment_name='IDX_EMP_JOB'; BYTES ---------- 5373952
