Oracle “dba_tables”介绍

　　DBA_TABLES describes all relational tables in the database. Its columns are the same as those in ALL_TABLES. To gather statistics for this view, use the ANALYZE SQL statement.

ALL_TABLES describes the relational tables accessible to the current user. To gather statistics for this view, use the ANALYZE SQL statement.

Related Views

• DBA_TABLES describes all relational tables in the database.

• USER_TABLES describes the relational tables owned by the current user. This view does not display the OWNER column.

Note:

Columns marked with an asterisk (*) are populated only if you collect statistics on the table with the ANALYZE statement or theDBMS_STATS package.

Column	Datatype	NULL	Description
OWNER	VARCHAR2(30)	NOT NULL	Owner of the table
TABLE_NAME	VARCHAR2(30)	NOT NULL	Name of the table
TABLESPACE_NAME	VARCHAR2(30)		Name of the tablespace containing the table; null for partitioned, temporary, and index-organized tables
CLUSTER_NAME	VARCHAR2(30)		Name of the cluster, if any, to which the table belongs
IOT_NAME	VARCHAR2(30)		Name of the index-organized table, if any, to which the overflow or mapping table entry belongs. If the IOT_TYPE column is not null, then this column contains the base table name.
STATUS	VARCHAR2(8)		If a previous DROP TABLE operation failed, indicates whether the table is unusable (UNUSABLE) or valid (VALID)
PCT_FREE	NUMBER		Minimum percentage of free space in a block; null for partitioned tables
PCT_USED	NUMBER		Minimum percentage of used space in a block; null for partitioned tables
INI_TRANS	NUMBER		Initial number of transactions; null for partitioned tables
MAX_TRANS	NUMBER		Maximum number of transactions; null for partitioned tables
INITIAL_EXTENT	NUMBER		Size of the initial extent (in bytes); null for partitioned tables
NEXT_EXTENT	NUMBER		Size of secondary extents (in bytes); null for partitioned tables
MIN_EXTENTS	NUMBER		Minimum number of extents allowed in the segment; null for partitioned tables
MAX_EXTENTS	NUMBER		Maximum number of extents allowed in the segment; null for partitioned tables
PCT_INCREASE	NUMBER		Percentage increase in extent size; null for partitioned tables
FREELISTS	NUMBER		Number of process freelists allocated to the segment; null for partitioned tables
FREELIST_GROUPS	NUMBER		Number of freelist groups allocated to the segment; null for partitioned tables
LOGGING	VARCHAR2(3)		Logging attribute; NULL for partitioned tables
BACKED_UP	VARCHAR2(1)		Has table been backed up since last change
NUM_ROWS*	NUMBER		Number of rows in the table
BLOCKS*	NUMBER		Number of used data blocks in the table
EMPTY_BLOCKS*	NUMBER		Number of empty (never used) data blocks in the table
AVG_SPACE*	NUMBER		Average amount of free space, in bytes, in a data block allocated to the table
CHAIN_CNT*	NUMBER		Number of rows in the table that are chained from one data block to another, or which have migrated to a new block, requiring a link to preserve the old ROWID
AVG_ROW_LEN*	NUMBER		Average length of a row in the table (in bytes)
AVG_SPACE_FREELIST _BLOCKS	NUMBER		Average freespace of all blocks on a freelist
NUM_FREELIST_BLOCKS	NUMBER		Number of blocks on the freelist
DEGREE	VARCHAR2(10)		Number of threads per instance for scanning the table
INSTANCES	VARCHAR2(10)		Number of instances across which the table is to be scanned
CACHE	VARCHAR2(5)		Indicates whether the table is to be cached in the buffer cache (Y) or not (N)
TABLE_LOCK	VARCHAR2(8)		Indicates whether table locking is enabled (ENABLED) or disabled (DISABLED)
SAMPLE_SIZE	NUMBER		Sample size used in analyzing this table
LAST_ANALYZED	DATE		Date on which this table was most recently analyzed
PARTITIONED	VARCHAR2(3)		Indicates whether this table is partitioned. Set to YES if it is partitioned.
IOT_TYPE	VARCHAR2(12)		If this is an index-organized table, then IOT_TYPE is IOT, IOT_OVERFLOW, or IOT_MAPPING. If this is not an index-organized table, then IOT_TYPEis NULL.
TEMPORARY	VARCHAR2(1)		Can the current session only see data that it place in this object itself?
SECONDARY	VARCHAR2(1)		Whether the trigger is a secondary object created by theODCIIndexCreate method of the Oracle Data Cartridge (Y |N)
NESTED	VARCHAR2(3)		Indicates whether the table is a nested table (YES) or not (NO)
BUFFER_POOL	VARCHAR2(7)		The default buffer pool for the object. NULL for partitioned tables
ROW_MOVEMENT	VARCHAR2(8)		Whether partitioned row movement is enabled or disabled
GLOBAL_STATS	VARCHAR2(3)		For partitioned tables, indicates whether statistics were collected for the table as a whole (YES) or were estimated from statistics on underlying partitions and subpartitions (NO)
USER_STATS	VARCHAR2(3)		Indicates whether statistics were entered directly by the user (YES) or not (NO)
DURATION	VARCHAR2(15)		Indicates the duration of a temporary table: SYS$SESSION: the rows are preserved for the duration of the session SYS$TRANSACTION: the rows are deleted after COMMIT Null for a permanent table
SKIP_CORRUPT	VARCHAR2(8)		Whether the Oracle Database ignores blocks marked corrupt during table and index scans (ENABLED) or raises an error (DISABLED). To enable this feature, run the DBMS_REPAIR.SKIP_CORRUPT_BLOCKSprocedure.
MONITORING	VARCHAR2(3)		Whether the table has the MONITORING attribute set
CLUSTER_OWNER	VARCHAR2(30)		Owner of the cluster, if any, to which the table belongs
DEPENDENCIES	VARCHAR2(8)		Indicates whether row-level dependency tracking is enabled (ENABLED) or disabled (DISABLED)
COMPRESSION	VARCHAR2(8)		Indicates whether table compression is enabled (ENABLED) or not (DISABLED); null for partitioned tables
DROPPED	VARCHAR2(3)		Indicates whether the table has been dropped and is in the recycle bin (YES) or not (NO); null for partitioned tables