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  • truncate 空间不释放问题

    SQL> set linesize 200

    SQL> select segment_name, sum(bytes / 1024 / 1024/1024)

      from dba_segments

      where segment_name='T_PM_DEBIT_CARD'

      group by segment_name;  2    3    4 

     

    SEGMENT_NAME                                                                 SUM(BYTES/1024/1024/1024)

    --------------------------------------------------------------------------------- -------------------------

    T_PM_DEBIT_CARD                                                                  16.1968994

     truncate table T_PM_DEBIT_CARD;

    SQL> select segment_name, sum(bytes / 1024 / 1024 / 1024)

      from dba_segments

     where segment_name = 'T_PM_DEBIT_CARD'

     group by segment_name;  2    3    4 

     

    SEGMENT_NAME                                    SUM(BYTES/1024/1024/1024)

    --------------------------------------------------------------------------------- -------------------------

    T_PM_DEBIT_CARD                                         .836181641

    为什么还有800M呢?

    SQL> alter table T_PM_DEBIT_CARD deallocate unused keep 0;

     

    Table altered.

     

    SQL> select segment_name, sum(bytes / 1024 / 1024 / 1024)

      from dba_segments

     where segment_name = 'T_PM_DEBIT_CARD'

     group by segment_name;  2    3    4 

     

    SEGMENT_NAME                                    SUM(BYTES/1024/1024/1024)

    --------------------------------------------------------------------------------- -------------------------

    T_PM_DEBIT_CARD                                         .051513672

    是因为initial 分配的缘故.

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  • 原文地址:https://www.cnblogs.com/hzcya1995/p/13352440.html
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