Oracle教程 2023-04-07

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

本站中文解释

Oracle视图ALL_CLUSTERS是一个字典视图，它记录着当前用户下的所有簇的元数据信息，如所有配置的簇的名称，相关的表，使用的存储表和簇的数据类型。

使用ALL_CLUSTERS视图可以获取系统中关于簇的所有信息，从而帮助用户更好地管理和维护簇和关联的表。举个例子，使用者可以运行一个SQL语句来查询当前用户所有的簇及其关联的表：

SELECT CLUSTER_NAME, RELATED_TABLE FROM ALL_CLUSTERS;

官方英文解释

ALL_CLUSTERS describes all clusters accessible to the current user.

Related Views

DBA_CLUSTERS describes all clusters in the database.
USER_CLUSTERS describes all clusters owned by the current user. This view does not display the OWNER column.

Column	Datatype	NULL	Description
`OWNER`	`VARCHAR2(128)`	`NOT NULL`	Owner of the cluster
`CLUSTER_NAME`	`VARCHAR2(128)`	`NOT NULL`	Name of the cluster
`TABLESPACE_NAME`	`VARCHAR2(30)`	`NOT NULL`	Name of the tablespace containing the cluster
`PCT_FREE`	`NUMBER`		Minimum percentage of free space in a block
`PCT_USED`	`NUMBER`		Minimum percentage of used space in a block
`KEY_SIZE`	`NUMBER`		Estimated size of cluster key plus associated rows
`INI_TRANS`	`NUMBER`	`NOT NULL`	Initial number of transactions
`MAX_TRANS`	`NUMBER`	`NOT NULL`	Maximum number of transactions
`INITIAL_EXTENT`	`NUMBER`		Size of the initial extent in bytes
`NEXT_EXTENT`	`NUMBER`		Size of secondary extents in bytes
`MIN_EXTENTS`	`NUMBER`	`NOT NULL`	Minimum number of extents allowed in the segment
`MAX_EXTENTS`	`NUMBER`	`NOT NULL`	Maximum number of extents allowed in the segment
`PCT_INCREASE`	`NUMBER`		Percentage increase in extent size
`FREELISTS`	`NUMBER`		Number of process freelists allocated to this segment
`FREELIST_GROUPS`	`NUMBER`		Number of freelist groups allocated to this segment
`AVG_BLOCKS_PER_KEY`	`NUMBER`		Number of blocks in the table divided by number of cluster keys
`CLUSTER_TYPE`	`VARCHAR2(5)`		Type of the cluster: `INDEX` – B*-Tree index `HASH` – Hash
`FUNCTION`	`VARCHAR2(15)`		If the cluster is a hash cluster, the hash function
`HASHKEYS`	`NUMBER`		If the cluster is a hash cluster, the number of hash keys (hash buckets)
`DEGREE`	`VARCHAR2(10)`		Number of threads per instance for scanning the cluster, or `DEFAULT`
`INSTANCES`	`VARCHAR2(10)`		Number of instances across which the cluster is to be scanned , or `DEFAULT`
`CACHE`	`VARCHAR2(5)`		Indicates whether the cluster is to be cached in the buffer cache (`Y`) or not (`N`)
`BUFFER_POOL`	`VARCHAR2(7)`		Buffer pool to be used for cluster blocks: `DEFAULT` `KEEP` `RECYCLE` NULL
`FLASH_CACHE`	`VARCHAR2(7)`		Database Smart Flash Cache hint to be used for cluster blocks: `DEFAULT` `KEEP` `NONE` Solaris and Oracle Linux functionality only.
`CELL_FLASH_CACHE`	`VARCHAR2(7)`		Cell flash cache hint to be used for cluster blocks: `DEFAULT` `KEEP` `NONE` See Also: Oracle Exadata Storage Server Software documentation for more information
`SINGLE_TABLE`	`VARCHAR2(5)`		Indicates whether this is a single-table cluster (`Y`) or not (`N`)
`DEPENDENCIES`	`VARCHAR2(8)`		Indicates whether row-level dependency tracking is enabled (`ENABLED`) or disabled (`DISABLED`)

本站中文解释

官方英文解释

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