Oracle supplies many PL/SQL packages with the Oracle server to extend database functionality and provide PL/SQL access to SQL features. You can use the supplied packages when creating your applications or for ideas in creating your own stored procedu…

One characteristic of an RDBMS is the independence of physical data storage from logical data structures. RDBMS的特点之一是物理数据与逻辑数据结构的独立性. Introduction to Schema Objects Schema Object Types Schema Object Storage Schema Object Dependencies SYS and SYSTEM S…

概述: (一)什么Oracle叫用户(user): A user is a name defined in the database that can connect to and access objects. 大意:Oracle用户是用连接数据库和访问数据库对象的.(用户是用来连接数据库访问数据库). (二)什么叫模式(schema): A schema is a collection of database objects (used by a user.). Schema objects…

Oracle Schema Objects Oracle Schema Objects——Tables——Oracle Data Types Oracle伪列 在Oracle数据库之中为了实现完整的关系数据库的功能,专门为用户提供了许多的伪列. “NEXTVAL”和“CURRVAL”就是两个默认提供的操作伪列Oracle Schema Objects——Sequences(伪列:nextval,currval) SYSDATE与SYSTIMESTAMP也属于伪列SQL Fundamentals…

方案(Schema)为数据库对象的集合,为了区分各个集合,我们需要给这个集合起个名字,这些名字就是我们在企业管理器的方案下看到的许多类似用户名的节点,这些类似用户名的节点其实就是一个schema,schema里面包含了各种对象如tables, views, sequences, stored procedures, synonyms, indexes, clusters, and database links.  一个用户一般对应一个schema,该用户的schema名等于用户名,并作为该用户缺…

Oracle Schema Objects Table Storage Oracle数据库如何保存表数据? Oracle Database uses a data segment in a tablespace to hold table data. Oracle 数据库使用表空间中的数据段保存表数据. As explained in "User Segments", a segment contains extents made up of data blocks. 如"用…

1.这是Schema的definition: A schema is a collection of database objects (used by a user.) Schema objects are the logical structures that directly refer to the database’s data.A user is a name defined in the database that can connect to and access objects…

Oracle Schema Objects Object Tables object type An Oracle object type is a user-defined type with a name, attributes, and methods. Oracle 对象类型是具有名称. 属性.和方法的用户定义类型. Object types make it possible to model real-world entities such as customers and purch…

Oracle Schema Objects Overview of Tables A table is the basic unit of data organization in an Oracle database. 表是Oracle数据库中的数据组织的基本单位. A table describes an entity, which is something of significance about which information must be recorded. 一个表描述了一个实…

Oracle Schema Objects 表分区 表- - 分区( partition )TABLE PARTITION 一段时间给出一个分区,这样方便数据的管理. 可以按照范围range分区,列表分区,哈希分区等. 创建表分区: SQL> create table t_part(id int) 2 partition by range(id) 3 (partition p1 values less than(5), 4 partition p2 values less than(10), 5…