You can change these database defaults, as described later in this section.ĭictionary managed tablespace-When you create a new dictionary managed tablespace, it is assigned the threshold values that Cloud Control lists for "All others" in the metrics categories "Tablespace Free Space (MB) (dictionary managed)" and "Tablespace Space Used (%) (dictionary managed)." You change these values on the Metric and Policy Settings page. Defaults for free space remaining thresholds for a new database are both zero (disabled). A newly created database has a default of 85% full for the warning threshold and 97% full for the critical threshold. Locally managed tablespace-When you create a new locally managed tablespace, it is assigned the default threshold values defined for the database. New tablespaces are assigned alert thresholds as follows: See " Monitoring a Database with Server-Generated Alerts" for more information. For dictionary managed tablespaces, Oracle Enterprise Manager Cloud Control (Cloud Control) provides this functionality. Free-space-remaining thresholds are more useful for very large tablespaces.Īlerts for locally managed tablespaces are server-generated. There are two ways to specify alert thresholds for both locally managed and dictionary managed tablespaces:įor both warning and critical thresholds, when space used becomes greater than or equal to a percent of total space, an alert is issued.īy free space remaining (in kilobytes (KB))įor both warning and critical thresholds, when remaining space falls below an amount in KB, an alert is issued. The database issues alerts at both thresholds. The critical threshold is a serious limit that warrants your immediate attention. The warning threshold is the limit at which space is beginning to run low. So Oracle deletes the objects in schema and then it drops the user automatically, Objects referred to these schema objects from other schema like views and private synonyms goes to invalid state.Two alert thresholds are defined by default: warning and critical. If we try to drop a user containing objects in his schema we must specify CASCADE word because Oracle does not allow you to delete a user containing objects. here the restrict word forces you to specify that schema with out objects. We can drop the schema by using the DROP SCHEMA RESTRICT statement, but it can not delete schema contained objects, so to drop the schema, it must be empty. We can create schema by using the CREATE SCHEMA statement, but Oracle automatically creates a user for that schema. It contains all objects created by the user associated to that schema.For Example if i created a user with name santhosh then oracle creates a schema called santhosh, Oracle stores all objects created by user santhosh in the santhosh schema. It's created automatically by Oracle when user created. The Schema Also Logical Structure to process the data in Database(Memory Component). SchemaĪctually Oracle Database contain logical and physical structure to process the data. We can create user by using CREATE USER IDENTIFIED BY. User is a account to connect database(Server). The both words, user and schema, are interchangeable, that's why most people get confused on these words. ![]() Its a physical Memory Component Connected to a Computer Installed with DBMS Software to manipulate the data in that Memory component,the computer installed with dbms software is called Server or Database Server.The both Server(Computer) and Database(memory component) are different but Most of times refered as Same based on situation. The Data base is a collection of data,where actually data stored. ![]() But using dbca (database creation assistant) is easier to get started. You can create a database with the create database statement, once you've installed the Oracle software stack. You should look at the Oracle Database Architecture documentation in the Concepts Guide (actually, that whole page is worth a read - there's a section about users and schemas higher up in that page) to get an introduction to what a database is, and what a database instance is - two important concepts. The database is the thing that contains all the users you've created, and their data (and a bunch of predefined system users, tables, views, etc. Once the user is created, an administrator can grant privileges to the user, which will enable it to create tables, execute select queries, insert, and everything else. This also "creates" the schema (initially empty) - you cannot create a schema as such, it is tied to the user. You create users with the create user statement. ![]() ![]() See this post on Stack Overflow: difference between a User and a Schema in Oracle? for more details and extra links. You can consider that a user is the account you use to connect to a database, and a schema is the set of objects (tables, views, etc.) that belong to that account. In Oracle, users and schemas are essentially the same thing.
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