Oracle 视图 DBA_SEGMENTS 官方解释，作用，如何使用详细说明
本站中文解释
Oracle 中视图DBA_SEGMENTS为DBA权限视图，可以查询和查看当前实例中所有表空间和段的相关信息，信息包括表空间名，段名，字节数，段类型等信息，方便数据库DBA查看每个表空间的大小及占用情况，可以进行合理的表空间管理。
使用方法：
1. 使用以下SQL查询当前实例的所有表空间的信息：
select * from dba_segments;
2. 使用以下SQL查询某个表空间下的段信息：
select * from dba_segments where tablespace_name=’表空间名’;
官方英文解释
DBA_SEGMENTS describes the storage allocated for all segments in the database.
Related View
USER_SEGMENTS describes the storage allocated for the segments owned by the current user’s objects. This view does not display the OWNER, HEADER_FILE, HEADER_BLOCK, or RELATIVE_FNO columns.
| Column | Datatype | NULL | Description |
|---|---|---|---|
|
| Username of the segment owner | |
|
| Name, if any, of the segment | |
|
| Object Partition Name (Set to | |
|
| Type of segment:
| |
|
| Subtype of LOB segment: | |
|
| Name of the tablespace containing the segment | |
|
| Absolute file number of the data file containing the segment header | |
|
| ID of the block containing the segment header | |
|
| Size, in bytes, of the segment | |
|
| Size, in Oracle blocks, of the segment | |
|
| Number of extents allocated to the segment | |
|
| Size in bytes requested for the initial extent of the segment at create time. (Oracle rounds the extent size to multiples of 5 blocks if the requested size is greater than 5 blocks.) | |
|
| Size in bytes of the next extent to be allocated to the segment | |
|
| Minimum number of extents allowed in the segment | |
|
| Maximum number of extents allowed in the segment | |
|
| Maximum number of blocks allowed in the segment | |
|
| Retention option for | |
|
| Minimum retention duration for | |
|
| Percent by which to increase the size of the next extent to be allocated | |
|
| Number of process freelists allocated to this segment | |
|
| Number of freelist groups allocated to this segment | |
|
| Relative file number of the segment header | |
|
| Buffer pool to be used for segment blocks:
| |
|
| Database Smart Flash Cache hint to be used for segment blocks:
Solaris and Oracle Linux functionality only. | |
|
| Cell flash cache hint to be used for segment blocks:
See Also: Oracle Exadata Storage Server Software documentation for more information | |
|
| Indicates whether the In-Memory Column Store (IM column store) is enabled ( | |
|
| Indicates the priority for In-Memory Column Store (IM column store) population:
| |
|
| Indicates how the IM column store is distributed in an Oracle Real Application Clusters (Oracle RAC) environment:
| |
|
| Indicates the duplicate setting for the IM column store in an Oracle RAC environment:
| |
|
| Indicates the compression level for the IM column store:
| |
|
| The value for columnar compression in the storage cell flash cache. Possible values:
|
Footnote 1
This column is intended for use with Oracle Exadata
See Also:
“USER_SEGMENTS”
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