INDEX_QUALIFERsysnameName of the index owner. Some database management system (DBMS) products allow for users other than the table owner to create indexes. In SQL Server, this column is always the same asTABLE_NAME. INDEX_NAMEsysnameName of the index. ...
A database index is a data structure that improves the speed of operations in a table. Indexes can be created using one or more columns, providing the basis for both rapid random lookups and efficient ordering of access to the records....
CONSTRAINT_INDEX VARCHAR2(3) 索引が制約の一部として作成されたかどうか(YESまたはNO)を示します 関連項目: 「DBA_INDEXES」 「USER_INDEXES」 DBMS_STATSパッケージの詳細は、『Oracle Database PL/SQLパッケージおよびタイプ・リファレンス』を参照してください。 前...
SQL> create index idx_id on dave(id)invisible; Index created. SQL> execdbms_stats.gather_table_stats(ownname =>'&owner',tabname=>'&tablename',estimate_percent => &est_per ,method_opt =>'forall columns size 1',degree=>°ree,cascade => true); Enter value for owner: sys Enter val...
一、视图视图是虚拟的表。与包含数据的表不一样,视图只包含使用时动态检索数据的查询。说明:DBMS支持Microsoft Access不支持视图,没有与SQL视图一致的工作方式。因此,这一课的内容不适用Microsoft Access。MySQL从版本5起开始支持视图,因此,这一课的内容不适用较早版本的My...
MS-SQL Server has the ability to use multiple indexes per table within a single query. As a result, MS-SQL Server's 7.0 multiple search condition query execution is greatly improved over previous versions because the user can virtually eliminate table scans (in which the DBMS reads every row...
CALL DBMS_RESOURCE_MANAGER.SET_CONSUMER_GROUP_MAPPING('FUNCTION', 'DDL', 'DDL_GROUP'); /* Enable the resource management plan */ SET GLOBAL resource_manager_plan = 'DDL_PLAN'; In this example, therootuser and theDDLfunction for executing DDL tasks are mapped to theDDL_GROUPresource consum...
SQL> create table colocated ( x int, y varchar2(80) ); 表已创建。 1begin 2for i in 1 .. 100000 3loop 4insert into colocated(x,y) 5values (i, rpad(dbms_random.random,75,'*') ); 6end loop; 7*end; 8/ PL/SQL过程已成功完成。
现在数据库系统主要基于三个层次进行数据库加密工作,即0S、DBMS内核层、DBMS外层。目前常用的办法是在DBMS外核层加密。DBMS外核层加密是将数据库加密系统做成DBMS的一个工具,其优点是不会加重数据库服务器的负载并可以实现网上传输加密,缺点是加密功能会受一些限制。作为一种通过加密方式来保护数据的专门系统,数据库加...
Der Name des Indexbesitzers. Verschiedene DBMS-Produkte ermöglichen neben dem Tabellenbesitzer auch anderen Benutzern das Erstellen von Indizes. Bei SQL Server ist diese Spalte stets mitTABLE_NAMEidentisch. INDEX_NAME sysname Der Name des Indexes. ...