Oracle 视图 ALL_PART_LOBS 官方解释，作用，如何使用详细说明

本站中文解释

Oracle视图 ALL_PART_LOBS 是用来查询当前用户拥有或可控制权限的全部基于 LOB 的分区表定义信息的一个系统视图，它不会涉及自动分区信息。它的具体字段如下：

– TABLE_OWNER：表的Ownner
– TABLE_NAME：表名
– PARTITION_POSITION：分区上的位置
– COLUMN_NAME：用于分区的LOB字段
– SEGMENT_NAME： KTF$存储段名
– RETENTION：LOB的保存期限

使用 ALL_PART_LOBS 视图的一般步骤如下：

1.通过查询ALL_PART_LOBS视图来获取全部基于 LOB 的分区定义信息。

2.根据所获取的信息来构建一个表（原表），并基于列上的LOB属性分区。

3.使用分区以增加表的存取性能。

官方英文解释

ALL_PART_LOBS displays table-level information about the partitioned LOBs accessible to the current user, including default attributes for LOB data partitions.

Related Views

DBA_PART_LOBS displays table-level information about all partitioned LOBs in the database.
USER_PART_LOBS displays table-level information about the partitioned LOBs owned by the current user. This view does not display the TABLE_OWNER column.

Column	Datatype	NULL	Description
`TABLE_OWNER`	`VARCHAR2(128)`	`NOT NULL`	Owner of the partitioned table containing the LOBs
`TABLE_NAME`	`VARCHAR2(128)`	`NOT NULL`	Name of the partitioned table containing the LOBs
`COLUMN_NAME`	`VARCHAR2(4000)`		Name of the LOB column
`LOB_NAME`	`VARCHAR2(128)`	`NOT NULL`	Name of the partitioned LOB
`LOB_INDEX_NAME`	`VARCHAR2(128)`	`NOT NULL`	Name of the partitioned LOB index
`DEF_CHUNK`	`NUMBER`	`NOT NULL`	Default value of `CHUNK` for a LOB data partition to be used when adding a partition
`DEF_PCTVERSION`	`NUMBER`	`NOT NULL`	Default value of `PCTVERSION` for a LOB data partition to be used when adding a partition
`DEF_CACHE`	`VARCHAR2(10)`		Indicates whether and how the LOB data is cached by default in the buffer cache: `YES` – LOB data is placed in the buffer cache `NO` – LOB data either is not brought into the buffer cache or is brought into the buffer cache and placed at the least recently used end of the LRU list `CACHEREADS` – LOB data is brought into the buffer cache only during read operations but not during write operations
`DEF_IN_ROW`	`VARCHAR2(3)`		Indicates whether LOB data < 4000 bytes is stored by default inline (in the row) (`YES`) or not (`NO`); that is, whether or not `ENABLE STORAGE IN ROW` was specified when the LOB column was created or last altered
`DEF_TABLESPACE_NAME`	`VARCHAR2(30)`		Default tablespace for a LOB data partition to be used when adding a partition
`DEF_INITIAL_EXTENT`	`VARCHAR2(40)`		Default value of `INITIAL` for a LOB data partition to be used when adding a partition, or `DEFAULT` if no `INITIAL` value was specified
`DEF_NEXT_EXTENT`	`VARCHAR2(40)`		Default value of `NEXT` for a LOB data partition to be used when adding a partition, or `DEFAULT` if no `NEXT` value was specified
`DEF_MIN_EXTENTS`	`VARCHAR2(40)`		Default value of `MINEXTENTS` for a LOB data partition to be used when adding a partition, or `DEFAULT` if no `MINEXTENTS` value was specified
`DEF_MAX_EXTENTS`	`VARCHAR2(40)`		Default value of `MAXEXTENTS` for a LOB data partition to be used when adding a partition, or `DEFAULT` if no `MAXEXTENTS` value was specified
`DEF_MAX_SIZE`	`VARCHAR2(40)`		Default value of `MAXSIZE` for a LOB data partition to be used when adding a partition, or `DEFAULT` if no `MAXSIZE` value was specified
`DEF_RETENTION`	`VARCHAR2(7)`		Default value of `RETENTION` for a LOB data partition to be used when adding a partition. Possible values for SecureFiles: `NONE` `AUTO` `MIN` `MAX` `DEFAULT` `INVALID` Possible values for BasicFiles: `YES` `NO`
`DEF_MINRET`	`VARCHAR2(40)`		Default value of `RETENTION MIN` for a LOB data partition to be used when adding a partition, or `DEFAULT` if no `RETENTION MIN` value was specified
`DEF_PCT_INCREASE`	`VARCHAR2(40)`		Default value of `PCTINCREASE` for a LOB data partition to be used when adding a partition, or `DEFAULT` if no `PCTINCREASE` value was specified
`DEF_FREELISTS`	`VARCHAR2(40)`		Default value of `FREELISTS` for a LOB data partition to be used when adding a partition, or `DEFAULT` if no `FREELISTS` value was specified
`DEF_FREELIST_GROUPS`	`VARCHAR2(40)`		Default value of `FREELIST GROUPS` for a LOB data partition to be used when adding a partition, or `DEFAULT` if no `FREELIST GROUPS` value was specified
`DEF_LOGGING`	`VARCHAR2(7)`		Default `LOGGING` attribute for a LOB data partition to be used when adding a partition: `NONE` – Not specified See Also: the `_LOBS` and `_LOB_PARTITIONS` views `YES` `NO`
`DEF_BUFFER_POOL`	`VARCHAR2(7)`		Default buffer pool for a LOB data partition to be used when adding a partition: `DEFAULT` `KEEP` `RECYCLE` NULL
`DEF_FLASH_CACHE`	`VARCHAR2(7)`		Default Database Smart Flash Cache hint to be used when adding a partition: `DEFAULT` `KEEP` `NONE` Solaris and Oracle Linux functionality only.
`DEF_CELL_FLASH_CACHE`	`VARCHAR2(7)`		Default cell flash cache hint to be used when adding a partition: `DEFAULT` `KEEP` `NONE` See Also: Oracle Exadata Storage Server Software documentation for more information
`DEF_ENCRYPT`	`VARCHAR2(4)`		Default value of `ENCRYPT` for a LOB data partition to be used when adding a partition. Possible values for SecureFiles: `YES` `NO` Possible value for BasicFiles: `NONE` – Not applicable
`DEF_COMPRESS`	`VARCHAR2(6)`		Default value of `COMPRESS` for a LOB data partition to be used when adding a partition. Possible values for SecureFiles: `LOW` `MEDIUM` `HIGH` `NO` – Compression is off Possible value for BasicFiles: `NONE` – Not applicable
`DEF_DEDUPLICATE`	`VARCHAR2(15)`		Default value of `DEDUPLICATE` for a LOB data partition to be used when adding a partition. Possible values for SecureFiles: `LOB` – Deduplicate `NO` – Keep duplicates Possible values for BasicFiles: `NONE` – Not applicable
`DEF_SECUREFILE`	`VARCHAR2(3)`		Indicates whether the LOB is SecureFiles (`YES`) or not (`NO`)
`DEF_MAX_INLINE`	`NUMBER`		Default inline LOB size (in bytes)