举比例如以下: SQL> Gruant dba to scott SQL> create table test(name char(10)); Table created. SQL> create table system.test(name char(10)); Table created. SQL> insert into test values(‘scott’); 1 row created. SQL> insert into system.test values(‘system’); 1 row created. SQL>...
–ORACLE_SIDrun1.sql spool C:ORACLE8IadminORACLE_SIDcreatecreatedb1 set echo on connect INTERNAL/oracle ALTER DATABASE DATAFILE ‘C:ORACLE8IoradataORACLE_SIDsystem01.dbf’AUTOEXTEND ON; CREATE ROLLBACK SEGMENT SYSROL TABLESPACE “SYSTEM” STORAGE (INITIAL100K NEXT 100K); ALTER ROLLBACK SEGMENT “...
在系统表user_tables中也可以看到segment_treated的字段里是“NO”或者“YES”说明了某张表是否分配了segment。说白了是为了可以节省少量的空间。 用下面的SQL语句查询,可以发现没有导出的表其 segment_created 字段值都是 'NO'。 Select segment_created,table_name from user_tables where segment_created = 'NO'...
Serializable transactions do not work with deferred segment creation. Trying to insert data into an empty table with no segment created causes an error. See Also: Oracle Database Concepts for general information on segment allocation and Oracle Database Reference for more information about the DEFERRE...
首先我们创建一个数据表justForTest,来观察数据库是否为此表分配segment。 SQL>createtablejustForTest(test1varchar2(2));Tablecreated 但是,对应的段segment对象,却没有创建出来,如下: selectsegment_name, BYTES, BLOCKS, EXTENTSfromuser_segmentswheresegment_name='JUSTFORTEST'; ...
SEGMENT_CREATED VARCHAR2(3) RESULT_CACHE VARCHAR2(7) CLUSTERING VARCHAR2(3) ACTIVITY_TRACKING VARCHAR2(23) DML_TIMESTAMP VARCHAR2(25) HAS_IDENTITY VARCHAR2(3) CONTAINER_DATA VARCHAR2(3) INMEMORY VARCHAR2(8) INMEMORY_PRIORITY VARCHAR2(8) ...
DEFERRED_SEGMENT_CREATIONspecifies the semantics of deferred segment creation. Ifset to true, then segments for tables and their dependent objects (LOBs,indexes) will not be created until the first row is inserted into the table. --如果deferred_segment_creation 设置为true,那么表的segments和相关的...
selectdr.tablespace_name, dr.segment_name, vr.statusfromdba_rollback_segs dr, v$rollstat vrwheredr.segment_id=vr.usn; 确实无误后,执行删除原有UNDOTBS1, droptablespaceUNDOTBS1includingcontentsanddatafiles; 再查看, SELECT*FROMDBA_DATA_FILES; ...
--- ---OWNERNOTNULLVARCHAR2(30)-- ALL_TABLES比USER_TABLES多了一列OWNER,以指明该表属于哪个用户-- 但除此以外表机构几乎一致TABLE_NAMENOTNULLVARCHAR2(30)TABLESPACE_NAME VARCHAR2(30)CLUSTER_NAME VARCHAR2...READ_ONLY VARCHAR2(3)SEGMENT_CREATED VARCHAR2(3)RESULT_CACHE VARCHAR2 1. 2. 3. 4...
段空间有两种管理方式,分别是手动段空间管理(Manual Segment Space Management,MSSM)和自动段空间管理(Auto Segment Space Management,ASSM)。 自动段空间管理(ASSM),它首次出现在Oracle 9.2中。自由列表FREELIST被位图所取代,它是一个二进制的数组,能够迅速有效地管理存储扩展和剩余区块(Free Block),因此能够改善分段...