Oracle强制索引优化数据库的运行效率（oracle强制使用索引）

With the increase of application complexity and data volume, the demand for data storage in the database is also higher and higher, and the performance requirements for the database are becoming more and more strict. How to optimize the performance of the database has become a major problem for many IT professionals. Using indexes correctly is an important part of optimizing the performance of a database. It can help you improve query performance and reduce I/O cost. Oracle support force index optimization methods in some scenarios, here explain how to use it.

First, let’s take a look at how Oracle creates an index. Generally speaking, when creating an index, Oracle will decide whether to use an index based on the information in the optimizer. Sometimes, the Oracle optimizer will not choose an index because it is not the most cost-effective or efficient. In this case, you can use the force index optimization method to tell the optimizer to use the index you specified.

To do this, you need to use the force index optimization keyword to indicate the index you specified, and modify the SQL statement. For example, you can use the following statement to force Oracle to use your specified MYINDEX index:

SELECT *

FROM mytable

WHERE id = ‘123’

FORCE INDEX (MYINDEX)

In addition, it is important to note that in order to successfully use the force index optimization method, we must ensure that the index you specify is the most appropriate index. If the specified index has poor performance, the performance of the query may be worse, so it is necessary to ensure that the index is appropriate when forcing the index.

In addition to forcing an index, there may be other algorithms used to optimize the performance of a poorly performing query. Common algorithms include re-writing the SQL statement, repartitioning data, reorganizing indexes, and so on. But before you start any other algorithm, don’t forget to try using the force index optimization method. It’s often the easiest and fastest way to improve your query performance.