在空表上创建索引后插入数据或在oracle上插入数据后创建唯一索引？ [英] Insertion of data after creating index on empty table or creating unique index after inserting data on oracle?

问题描述

哪个选项更好更快？
在空表上创建索引或在插入数据后创建唯一索引后插入数据。我有大约10M行要插入。哪个选项会更好，以便我可以减少停机时间。

Which option is better and faster? Insertion of data after creating index on empty table or creating unique index after inserting data. I have around 10M rows to insert. Which option would be better so that I could have least downtime.

推荐答案

首先插入数据，然后创建索引。

Insert your data first, then create your index.

每次执行UPDATE，INSERT或DELETE操作时，表中的所有索引也必须更新。因此，如果首先创建索引，然后插入10M行，则索引也必须更新10M次（除非您正在进行批量操作）。

Every time you do an UPDATE, INSERT or DELETE operation, any indexes on the table have to be updated as well. So if you create the index first, and then insert 10M rows, the index will have to be updated 10M times as well (unless you're doing bulk operations).

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