当freelist里面没有记录了，也就是块空间已经没有办法容纳新的记录了，这时候就需要扩展extent.

这里有一个脚本来查看段空间使用情况。

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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 )

-- this procedure uses authid current user so it can query DBA_*

-- views using privileges from a ROLE and so it can be installed

-- once per database, instead of once per user that wanted to use it

authid current_user

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;

l_segment_space_mgmt        varchar2(255);

l_unformatted_blocks number;

l_unformatted_bytes number;

l_fs1_blocks number; l_fs1_bytes number;

l_fs2_blocks number; l_fs2_bytes number;

l_fs3_blocks number; l_fs3_bytes number;

l_fs4_blocks number; l_fs4_bytes number;

l_full_blocks number; l_full_bytes number;

-- inline procedure to print out numbers nicely formatted

-- with a simple label

procedure p( p_label in varchar2, p_num in number )

is

begin

dbms_output.put_line( rpad(p_label,40,'.') ||

to_char(p_num,'999,999,999,999') );

end;

begin

-- this query is executed dynamically in order to allow this procedure

-- to be created by a user who has access to DBA_SEGMENTS/TABLESPACES

-- via a role as is customary.

-- NOTE: at runtime, the invoker MUST have access to these two

-- views!

-- this query determines if the object is a ASSM object or not

begin

execute immediate

'select ts.segment_space_management

from dba_segments seg, dba_tablespaces ts

where seg.segment_name      =

_segname

and (

_partition is null or

seg.partition_name =

_partition)

and seg.owner =

_owner

and seg.tablespace_name = ts.tablespace_name'

into l_segment_space_mgmt

using p_segname, p_partition, p_partition, p_owner;

exception

when too_many_rows then

dbms_output.put_line

( 'This must be a partitioned table, use p_partition => ');

return;

end;

-- if the object is in an ASSM tablespace, we must use this API

-- call to get space information, else we use the FREE_BLOCKS

-- API for the user managed segments

if l_segment_space_mgmt = 'AUTO'

then

dbms_space.space_usage

( p_owner, p_segname, p_type, l_unformatted_blocks,

l_unformatted_bytes, l_fs1_blocks, l_fs1_bytes,

l_fs2_blocks, l_fs2_bytes, l_fs3_blocks, l_fs3_bytes,

l_fs4_blocks, l_fs4_bytes, l_full_blocks, l_full_bytes, p_partition);

p( 'Unformatted Blocks ', l_unformatted_blocks );

p( 'FS1 Blocks (0-25)  ', l_fs1_blocks );

p( 'FS2 Blocks (25-50) ', l_fs2_blocks );

p( 'FS3 Blocks (50-75) ', l_fs3_blocks );

p( 'FS4 Blocks (75-100)', l_fs4_blocks );

p( 'Full Blocks        ', l_full_blocks );

else

dbms_space.free_blocks(

segment_owner     => p_owner,

segment_name      => p_segname,

segment_type      => p_type,

freelist_group_id => 0,

free_blks         => l_free_blks);

p( 'Free Blocks', l_free_blks );

end if;

-- and then the unused space API call to get the rest of the

-- information

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( 'Total Blocks', l_total_blocks );

p( 'Total Bytes', l_total_bytes );

p( 'Total MBytes', trunc(l_total_bytes/1024/1024) );

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;

/

[/php]