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 IOTIOT_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
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