做一个 initial 大于 uniform size 乘以 minextents 的实验,总结出initial extent的分配规律

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做一个 INITIAL EXTENT 大于 UNIFORM size 乘以 MINEXTENTS 的实验。总结出initial extent的分配规律

Connected to:Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit ProductionWith the Partitioning, OLAP, Data Mining and Real Application Testing optionsSQL> alter system set deferred_segment_creation=false;System altered.SQL> show parameter deferNAME                                 TYPE        VALUE------------------------------------ ----------- ------------------------------deferred_segment_creation            boolean     FALSESQL> create tablespace test_uni_sz_1m   2  datafile '/u01/app/oracle/oradata/test/test_uni_sz_1m_01.dbf' size 200m  3  extent management local uniform size 1m;Tablespace created.SQL> create table test_tab_3 (col1 varchar2(2)) tablespace test_uni_sz_1m storage(initial 10m minextents 3); Table created.SQL> select bytes from dba_extents where segment_name = 'TEST_TAB_3' and owner = 'SCOTT';     BYTES----------   1048576   1048576   1048576   1048576   1048576   1048576   1048576   1048576   1048576   1048576   1048576     BYTES----------   104857612 rows selected.SQL> show user    USER is "SCOTT"SQL>

结果是分配了12个大小为1M（即：uniform size）的 extents。

貌似是前10个 1M 对应minextents的第一个，后2个1M对应 minextents的第二个和第三个。

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