DML command and Index

最新推荐文章于 2025-11-24 12:14:31 发布

翻译最新推荐文章于 2025-11-24 12:14:31 发布 · 347 阅读

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#command #insert #delete #oracle #query

本文介绍了数据库中数据操作语言(DML)的基本命令，包括创建、更新和删除记录的方法，并详细解释了索引的作用及其如何加速数据检索过程。

Data manipulation commands are used to manage data. Using DML command, you can create new records, update records and delete records. The following commands fall in this category.

SELECT - retrieve data from the a database
INSERT - insert data into a table
UPDATE - updates existing data within a table
DELETE - deletes all records from a table.

What is an Index?

Index in oracle helps to trace the information faster just like an index in a book. Index entries keep information about the columns that are part of the index in a sorted order. If you query data with an index, the data retrieval is much faster.