Oracle Freelist和HWM原理及性能优化

    SQL> 
         create  or  replace  procedure show_space 
        ( p_segname  in varchar2, 
        p_owner  in varchar2  default  user, 
        p_type  in varchar2  default  'TABLE', 
        p_partition  in varchar2  default  NULL ) 
         as 
        l_free_blks number; 
        l_total_blocks number; 
        l_total_bytes number; 
        l_unused_blocks number; 
        l_unused_bytes number; 
        l_LastUsedExtFileId number; 
        l_LastUsedExtBlockId number; 
        l_last_used_block number; 
         procedure p( p_label  in varchar2, p_num  in number ) 
         is 
         begin 
        dbms_output.put_line( rpad(p_label,40, '.') || p_num ); 
         end; 
         begin 
        dbms_space.free_blocks 
        ( segment_owner => p_owner, 
        segment_name => p_segname, 
        segment_type => p_type, 
        partition_name => p_partition, 
        freelist_group_id => 0, 
        free_blks => l_free_blks ); 
        dbms_space.unused_space 
        ( segment_owner => p_owner, 
        segment_name => p_segname, 
        segment_type => p_type, 
        partition_name => p_partition, 
        total_blocks => l_total_blocks, 
        total_bytes => l_total_bytes, 
        unused_blocks => l_unused_blocks, 
        unused_bytes => l_unused_bytes, 
        last_used_extent_file_id => l_LastUsedExtFileId, 
        last_used_extent_block_id => l_LastUsedExtBlockId, 
        last_used_block => l_last_used_block ); 
        p(  'Free Blocks', l_free_blks ); 
        p(  'Total Blocks', l_total_blocks ); 
        p(  'Total Bytes', l_total_bytes ); 
        p(  'Unused Blocks', l_unused_blocks ); 
        p(  'Unused Bytes', l_unused_bytes ); 
        p(  'Last Used Ext FileId', l_LastUsedExtFileId ); 
        p(  'Last Used Ext BlockId', l_LastUsedExtBlockId ); 
        p(  'Last Used Block', l_last_used_block ); 
         end; 
        过程已创建。