What is the difference between a user and a schema in Oracle?
相关问题
- Can I skip certificate verification oracle utl_htt
- how to calculate sum time with data type char in o
- keeping one connection to DB or opening closing pe
- System.Data.OracleClient not working with 64 bit O
- How can I get rid of dynamic SQL
相关文章
- node连接远程oracle报错
- oracle 11g expdp导出作业调用失败,提示丢包。
- 执行一复杂的SQL语句效率高,还是执行多少简单的语句效率高
- Oracle equivalent of PostgreSQL INSERT…RETURNING *
- Difference between FOR UPDATE OF and FOR UPDATE
- Oracle USING clause best practice
- Is there a method in PL/SQL to convert/encode text
- PHP PDO installation on windows (xampp)
Schema is a container of objects. It is owned by a user.
User: Access to resource of the database. Like a key to enter a house.
Schema: Collection of information about database objects. Like Index in your book which contains the short information about the chapter.
Look here for details
This answer does not define the difference between an owner and schema but I think it adds to the discussion.
In my little world of thinking:
I have struggled with the idea that I create N number of users where I want each of these users to "consume" (aka, use) a single schema.
Tim at oracle-base.com shows how to do this (have N number of users and each of these users will be "redirected" to a single schema.
He has a second "synonym" approach (not listed here). I am only quoting the CURRENT_SCHEMA version (one of his approaches) here:
It's very simple.
A user may be given access to schema objects owned by different Users.
Schema is an encapsulation of DB.objects about an idea/domain of intrest, and owned by ONE user. It then will be shared by other users/applications with suppressed roles. So users need not own a schema, but a schema needs to have an owner.
--USER and SCHEMA
The both words user and schema are interchangeble,thats why most people get confusion on this words below i explained the difference between them
--User User is a account to connect database(Server). we can create user by using CREATE USER user_name IDENTIFIED BY password .
--Schema
Actually Oracle Database contain logical and physical strucutre to process the data.The Schema Also Logical Structure to process the data in Database(Memory Component). Its Created automatically by oracle when user created.It Contains All Objects created by the user associated to that schema.For Example if i created a user with name santhosh then oracle createts a schema called santhosh,oracle stores all objects created by user santhosh in santhosh schema.
We can create schema by CREATE SCHEMA statement ,but Oracle Automatically create a user for that schema.
We can Drop the schema by using DROP SCHEMA schama_name RESTRICT statement but it can not delete scehema contains objects,so to drop schema it must be empty.here the restrict word forcely specify that schema with out objects.
If we try to drop a user contain objects in his schema we must specify CASCADE word because oracle does not allow you to delete user contain objects. DROP USER user_name CASCADE so oracle deletes the objects in schema and then it drops the user automatically,Objects refered to this schema objects from other schema like views and private synonyms goes to invalid state.
I hope now you got the difference between them,if you have any doubts on this topic,please feel free to ask.
Thank you.